FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF WATER AND ENERGY I FEASIBILITY STUDY AND DETAIL DESIGN OF BALE GADULA IRRIGATION PROJECT SECTION I - DESIGN REPORTS VOLUME VII - OPERATION AND MAINTENANCE MANUAL DETAIL DESIGN REPORT OCTOBER 2011 in association with Water Works Design and Spervision Enterprise (WWDSE) and 1 ech nocarts PVT LTD (ICT)i n LIST OF VOLUMES SECTION 1 - DESIGN REPORTS VOLUME 1 EXECUTIVE SUMMARY VOLUME II DESIGN OF WEIR AND HEAD REGULATOR ' VOLUME III DESIGN OF IRRIGATION AND DRAINAGE SYSTEM M R VOLUME IV DESIGN OF STRUCTURES ON CANAL AND DRAINAGE SYSTEM VOLUME V DESIGN OF HYDRO MECHANICAL GATES VOLUME VI INFRASTRUCTURE DESIGN VOLUME VII OPERATION AND MAINTENANCE MANUAL SECTION II - DRAWING ALBUM PART 1 DIVERSION WEIR AND HEAD REGULATOR PART II i IRRIGATION AND DRAINAGE SYSTEM H ■ M ■ M ■ H ■ M PART III CANAL AND DRAINAGE STRUCTURES PART IV HYDROMECHANICAL GATES PARTV INFRASTRUCTURE DESIGNS SECTION III - TENDER DOCUMENTS VOLUME VIII BID DOCUMENTS VOLUME IX TECHNICAL SPECIFICATIONS VOLUME X BILL OF QUANTITIES ■Ministry of Water and Energy - Feoerai Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual TABLE OF CONTENTS LIST OF VOLUMESI TABLE OF CONTENTS.................................................................................................................................................... II LIST LIST LIST OF APPENDIXV 1. INTRODUCTION1 11 General Background1 OF OF TABLEV FIGUREV 1.2 Objectives.......................................................................................................................................... 2 13 Scope of the Report2 14 Methodologies .................................................................................................................................. 3 1.5 Report Outline 2. BALE-GADULA IRRIGATION & DRAINAGE PROJECT (BAGIDP)4 2 1 DESCRIPTION OF THE PROJECT 4 3 2.1.1 Location ................................................................................ —4 2.1.2 Alt'tude, Climate & Hydrology 4 2.1 3 Basic Agricultural Features of tne Project Area 7 2.1 4 Existing Irrigated Agriculture Practices ............... .... ....................................................................... 9 2.1.5 Potential Command Area of BAGID Project .....................................................................................9 2 1.6 Crop Planning ana Cropping Pattern 2.1.7 Soil and Land Suitaoihty14 2.17 1 Landuse & Land Forms ...................................................... 14 9 2.17.2 Soils Physical Charactenstics —.............................................................................................. 14 2.1.7 3 Hydraulic Features of Sons-................................................................ -........... -16 2 17 4 Chemic3i Properties ot Soils 218 Socioeconomic Features of tne Protect Area18 2 2 Description of Works/Project Components.. 2.3 Irrigation System Layout21 18 18 2.3.1 Layout for Canoi Networks ana Ternary Units (TUs)21 2.3.2 Furrow Layout 73 3. THE OPERATION & MAINTAINANCE MANAGEMENT STRUCTURE............................. .... 24 3 1 Principles of the O and M Management Structure24 3 1.1 Project Management 74 3.2 Duties andResponsibiuties of the irrigation Project Management unit (PMU)25 3.3 accountability of the PMU25 3.4 Some important Basic cactsofthe Project26 3.5 Areas of Activities of WUA’s27 3.6 water Users Associations and DA vs Command AREA Ratio27 3 7 Functionsof WUA's-................................................................................................................................. 28 3.8 proposed Organizational Structure for the PMU 3.8.1 Technical Advisory Committee 29 29 3 8 2 Project Management Unit (PMU) 29 3 82 1 Major Functions ...................................................................................... 30 3.9 2 2 Functions of Development Agents 30 3 8.3 Proposed Manpower Requirement 3 8 3 1 Qualification Requirement 4 IRRIGATION SYSTEM OPERATION SERVICES 4 1 Soil-Water-Piant Relationships 4 11 Generals 31 .............................. ..................... 33 36 . . 36 WWDSE Addis Adana in Association with 11 Detail Design of Bale Gadula Irrigation & Drainage Project ICT Pvt Ltd and ABCE PLn October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I. Volume - VII Operation and Maintenance Manual 412 The Soil.......................................................................................................................................... 36 4 13 Soil Texture 4 14 Soil Structure 36 37 4 15 Storage of Soil Moisture........................................................................................... 37 4 1.6 Soturotion....................................................................................................................................... 37 4 17 Field Capacity 4 1.8 Permanent Wilting Point ... 37 38 4 1.9 Available Water/Moisture (AW)...................................................................................................... 39 4 2 Soil-Water Availability to Plants............................................................................................... 40 4 3 Measuring Soil Moisture...................................................................................................................41 4 3 1 Data Collection/Sampling Procedures............................................................................................ 41 4.3.2 instruments for Measuring soil Moisture................................... -................................................. 42 4 4 Principles of Farm Operation...........................................................................................................43 4.5 Basic Objectives of Farm Operation ............................................................................................. 44 4 6 Planning for Operation.................................................................................................................... 44 4 7 Estimating Future Water Supply ................................................................................................... 45 4 8 Estimating Water Demand ............................................................................................................... 45 4 9 Matching Supply and Demand......................_.................................................................................. 46 4 10 Matching Supply and Demand under Limited Supply Conditions..................................................47 4 11 Methods of Water Distribution ..................................................................................................... 49 4 12 irrigation Schedules ........................................................................................................................ 50 4 13 irrigation Scheduling in the BalE-Gadula irrigation Project..................................................... 51 4 13 1 Irrigation Time .......................................... _..................................................................................... SI 4 13.2 Tertiary unit Levei Scneduhna................................................................................................. 52 4 13 3 Irrigation Scheduling at Individual Crop Leve1 .... ........................ .................. 53 5. OPERATION AT CONTROL POINTS...................................................................................................................................54 5 1 The Principles of Control and Operation................................................................................... 54 5.2 variables *or Con’^ol...................................................................................................................... 54 5 3 Control Points in Bale-Gadula Command System ................................................... 55 5 4 Stage Discharge Curves atthe headwork .............................................................. 55 5 4.1 Stage-Discharge Curve for the Sluice Gate . ............................................................. 55 5.4 2 Stage -Discharge Curve for the mead Regulator...................~...................................56 5.4 3 Stage-Discharge Curve for tne Brooa Crested Weir.............................................. 57 5.4 4 Stage-Discharge Curve for tne Partial Flume.........................................................58 5.5 Stage-Discharge Curves atthe Division Boxes in the Canal Network... ................................ 59 5 6 Discharge Measurements ................... ............................................................................................. 61 6. INSPECTION OF WORKS............................................................................................................................................ -....... 62 6 1 Diversion Structure ......................................................................................................... 62 6.1.1 General......... ......................................................................................................................... 62 61.2 Aprons.................................................................................................................. 62 6 13 impervious Floors............. „............................................................................ ..................................... 62 614 Canai Head Regulator.......................................................................................................................... 63 6.1.5 Performance of Structure ............................................................................................................63 6 15 1 Uplift Pressure................................................................................................................. 63 6 15 2 Hydraulic jump profile 6 15 3 Suspended Sediment 6 15 4 Settlement and remedial measures 6 7 5 5 Aggregations upstream ... 64 64 64 . 64 6 7 5 6 Discharge distnbution and cross-flow 64 6 15 7 Pond Capacity 64 6 16 Operation ana Regulation ......... . .. 65 617 Pre-Ramy Season Operation ............. 65 6 17 1 Rainy Season Operation 6 17 2 Post Rainy Season Operation 6 18 Stuay of Imogeries 6 1 9 of He"1 ..... 69 66 68 69 WWDSE Addis Apana in A^^oc.arion with -m- Detail Design of Bale Gadula Irrigation & Drainage Project ICT °vt etc and ABOEOctober 2Q11Ministry of Water and Energy - Section - I, Volume - VII Federal Democratic Republic of Ethiopia_______ _____________________Operation and Maintenance Manual 6 1 10 List of Referred Indian Standards..................................................................................................... 69 6 2 Maintenance of Guide Bunds ... . ... ......................... 70 6 2 1 General ....................................................................................................................................... 70 6 2.2 Maintenance during floods.......................................................................................................... 70 6.2 3 Maintenance after Floods...............................................................................................................71 7. MAINTENANCE OF HYDRO-MECHANICAL INSTALLATIONS........................................................................................ 72 7 1 General.............................................................................................................................................. 72 7 2 Operation of Gates.......................................................................................................................... 72 7.3 Maintenance of Gates..................................................................................................................... 72 7 3 1 Gate Grooves and Seals................................................................................................................ 74 7.3.2 Seals.............................................................................................................................................. 74 7.3.3 Staunching Pipes...........................................................................................................................74 7.3.4 Steel Wire Ropes.......................................................................................................................... 74 7.3.5 Roller Trains ana Fixed Rollers..................................................................................................... 74 7.3.6 Wmches/Hoist...........................-................................................................................................... 75 7.3.7 issue of Certificate.......................................................................................................................... 75 7.4 LIGHTING ......................................................................................................................................... 75 7.5 Painting............................................................................................................................................. 75 7.6 Hoists................................................................................................................................................ 75 8. MAINTAINANCE OF CANAL AND DRAINAGE SYSTEM...................................................... 76 8 1 Maintenance of Canal System ........................................................................................................ 76 8.2 Bed and Berm...................................... -............................................................................................. 76 8.2.1 Bed............................................................................................ :...............................................76 8.2.2 Escapes ........................................................................................................................................ 77 8.2.3 Berm...............................................................................................................................................77 8.2 4 Silt Clearance............................................................................................................. 77 8.2.5 Discharge Measurements..............................................................................................................77 8.2.6 Banks................. -........................................................................................................................... 78 8.2 7 Sources of Earth for Repair....................................................................................... 79 8.2 8 Roods and Romps.................................................................................................... 79 8.2.9 vegetation Growth......................................................................................................................... 50 8.3 Drains Maintenance...........................................................................................................................81 8.3.1 Structures on Drains...................................................................................................................... 51 8.4 Plantation ......................................................................................................................................... 81 8.5 Maintenance of Lined Portions of Canals.....................................................................................82 8.5 1 Efficient Working..........................................................................................................82 8.5.2 Inspections of Lining...................................................................................................................... 82 8.5.3 Maintenance of Lining....................................................................................................................82 8 6 Carriage of Authorized Discharge 83 8.7 Performance of Canal..................... -.............................................................................................. 83 8.8 Maintenance of Embankments......................................................................................................... 83 8.9 Pre Rainy Season Maintenance.......................................................................................................84 8.9.1 Maintenance during the Rainy Season................................................................................................85 9. MAINTENANCE OF CANAL AND DRAINAGE STRUCTURES..............................................86 9.1 Outlets............................................................................................................................................... 86 9.2 Gates of Canals............................................................................................................................... 87 9.3 Over growth of Grass ano bushes (Jungle Clearance) ............................................................ 87 9 4 Regulation......................................................................................................................................... 87 9 5 Cross Drainage works 9 5 1 Inspection 88 88 9 5.2 Damages to Cross Drainage Works and Remedial Measures.................................................... 89 9 5.3 Remedial measures for the oamages to cross drainage works... go 9 5 4 Maintenance .............. ................................................................................................... 91 9 5 4 1 Before Rainy season ................. 91 WWDSE hbddis Ababa in Association with -iv- Detail Design of Bale Gadula Irrigation & Drainage Project ICT Pvt Ltd and ABCE PLC Octobet 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - l. Volume - VII Operation and Maintenance Manual 9 5 4 2 Dunng Rainy Season .........................................................-....................................................... 91 9 5 4 3 Post R.unv season . 9.6 implementation jf Maintenance LIST OF TABLE 91 ........ -92 Table 2 i Monthly Rainfall Series at Goro Observation Station.... ............. . ..........—...... -..............-......... 5 Table 2 2 Mean Monthly imflDw (cumecs) Series of Wt»3 River at Alem-KeremGaug.ng Station... —.................... . 6 Table 2.3 length of Growing Stages (LGP) of proposed crops /days......... ................ ............... ................ ................ ................ ................ 13 Table 2.4 Crop Factor in Crop Development Stage....-...................................................................................... 14 Table 2.5 Summary of infiltration Rate and hvorauuc Conductivii < Measurement ................................................ 16 Table 2.6 Soil Moisture Characteristics Curve & Available Water holding Capacity of the SMUs...... 17 Table 2 7 : Salient Features of Head Works................................................................................................. 19 Table 2 8 Summary of Type of Structures Designed................................................................................. 21 Table 2 9 layout of BAGCOMA-i .....................................................................................................................22 Table 3 1 Number of tus and WUAs Proposed...............................................................................................28 Table 3.2 Project Manager s Office .............................................................................................................. 31 Table 3 3. Administration Service................................................................................................................... 32 Table 3 4 Water Management & Environment Protection Section............................................................. 32 Table 3 5. Technical Services CIVIL................................................................................................................ 32 Table 3 6 Technical Services mechanical... ...................................................................................................33 Table 3 t Summary of Staffing Plan 33 Table 3 8 Proposed Qualification for Requirements................................................................................... 33 Table4 l Available Watfo holding Capacity of Soils of Different Texture.............................................. 40 T Table 4 2 irt’ERp»fA 5 . T’.ns»ometer Readings . ... Table 4.3 Summary of Soil intake Family Salient Features. .............. .7.......................................... 42 .......................................................... 52 Table 4 4 Features of the irrigation System................................................................................................. 53 Table 5 1 Profile of DBs n ’me BalaGadula Command System ........................... ........................ 60 LIST OF FIGURE Figure 2.1 Schematics of crop coefficient as impacted with soil evaporation &leaf Coverage..............13 Figure 2.2 Details of irrigation System layout .......................................................................................... 23 Figure 3-1 Bale-Gadula irrigation Project - PMU.........................................................................................35 Figure 5.1 Stage-Discharge Relationship of Sluice Gate..... 56 Figure 5.2 Stage-discharg curve for Broa^ Crested Weir at the head Regulator................................ 57 Figure 5 3 Stage-discharge Curve for the Partial Flume located at the Head Regulator.................... 58 Figure 5 4 Stage-Discharge Curve for Orifices in the Division Boxes ................................................... 61 LIST OF APPENDIX Appendix li Crop Groups According to Soil Water Depletion ... Appendix ll Irrigation Scheduling at Tertiary unit (TU) level 97 ................................. 99 appendix ill Format of Water Delivery in each canal ................................................................................ 131 WWDSE Addis Ababa m Association with -✓- Detail Des<qn of Sale Gaaula Irngation & Drainage Project iCT P.’ ^ j’ ai '-E'E ~ October 2011Ministry of Water ano Energy - Federal Democratic Republic of Ethiopia 1. INTRODUCTION 1.1 General Background Section -1, Volume - VII Operation and Maintenance Manual Irrigation has been practiced by mankina for several thousand years yet only in the present century have extensive studies been conducted in the general area of water-soil-plant relationships These relationships, commonly known as irrigation management involve irrigation practice on the farm or on individual fields Improper irngation may waste large amounts of water leach soil nutrients, and impair the productivity of the soil that may lead to considerable loss of production if allowed to sustain more within the system, or yield losses may occur if insufficient water is applied Water for irrigation and other uses is becoming more and more valuable due to the increasing cost of irrigation projects and a limited supply of good quality water The problem of limited water supply is exacerbated with high nydrologic variability as in the case of Bale-Gadula irrigation and drainage project Due to the random process of rainfall and its high vanability stream flows exhibit to acauire similar hydrologic features that impacts operation of irrigation systems and also impacts water management practices of irrigated farm systems Water management practices in any given irrigated farm system shall, therefore nave the objective of managing the supply and demand sides of the irrigated agnculture system and apply optimum allocation and equitable distribution of water across the board of an irrigation system To do so we must learn on how to distnbute the available water to the individual farms so that optimum moisture content can be acquired ana prevent an excessive application of water at individual field This action helps irrigated farms to acquire optimum soil-moisture regime in the growing periods whicn intern maximizes production per unit volume of water On the otner hand by preventing excessive applications we can reduce losses in the system and preclude tne degradation of the land which finally fosters high crop production and increased household level income that finally alleviates food insecurity ana reduces poverty Water management practices in surface irrigated agriculture system shall be giving emphasis to system losses especially at application level Surface runoff ana deep percolations are thougnt to be important components of system losses to be seen as important design variables in water management practices of irngated agnculture system For instance water waste by surface runoff is difficult to prevent while irrigating sloping fields particularly when water is turned into furrow or strip checks allowed to run the full length and out the lower end for hours This waste could be controlled by reducing the rate of flow into the furrows or strip checks, once the water has reacned the lower end of the field Loss of water from runoff is easy to observe On the other nand. a loss aue to deep percolation, which is the movement of water down to a depth below the roots of plants is difficult to observe Nevertheless a large part of the water applied by irrigation may be lost by aeeD percolation These losses are the result of over-irrigation or of water being left on an area longer tnan necessary Where furrows are too long or where water is rur over the iana for long distance almost WWDSE 'iddis Aoaoa m Association with -1- Detail Design of Bale Gaduia Irrigation & Drainage Projec' >0^ Pvt Ltd ann-\BCE P'-C October 201 ’Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - /, Volume - VII Operation aarnxc invariably it will be wanted by deep percolation in the upper ends of the furrow or fields and also where it may pond at the lower end of the field Deep percolation losses occur on rough or unleveled land, and that not properly graded for irrigation the water ponds to a considerable depth on the low areas during the irrigation of high spots Improper irrigation not only waste water and/or reduces crop yields but frequently results in plant nutnents being leached from the soil. Excessive application of water causes high water tables or seepage spots to develop which may be corrected only by the construction of expensive drainage systems In addition, salts accumulate and an alkali soil may develop Improving irrigation practice would be much easier if we could see below the soil surface and observe wnat is taking place, i.e how rapidly the water moves downward and how far it penetrates the soil what happens when it reaches a hard soil layer how fast and how far it moves laterally from a furrow; how and wnere the water is stored in the soil, how it is removed from the soil by plant roots the rate of removal and other underground water conditions This in turn prevails the importance of understanding the water balance of the system to develop effective water management practices in an irrigated agnculture like ours The aforementioned discussions reveal the importance of both project management and operation and maintenance manuals for assisting smooth operation of irrigated agriculture systems and finally to acquire high system efficiency both in terms of supply management and farm unit productivity per unit volume of water This is the very reason for this part of the project report has been conceived 1.2 Objectives Effective water management practice is highly related to system maintenance and regulation activities wnich in general describe operation and maintenance principles of irrigated agriculture works Two important pnnciples ir. developing proper water management practices include (i) proper operation of irrigated agriculture systems; and (ii) proper implementation of maintenance activities for irrigated agnculture systems so that system operation can be enhanced which finally results high productivity per unit volume of water the very scarce resource and yet important element in the development of agriculture. The pnmary objective of this report is therefore to establish proper guidelines and procedures on the operation and maintenance aspects of the Baie-Gadula Irrigation and Drainage Project 1.3 Scope of the Report The principles of water management as discussed in the preceding sections reveals that project management is an important tool to foster effective operation and maintenance activities in irrigated agriculture Project management involves two important aspects (i) institutional and link/liaison of the project within and WWDSE Addis Ababa in Association with -2- Detail Design of B&e Gadula Imgation & Drainage Project 10^ Pvt Ltd ano ABPE pLC October 20' tMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual outside of its system, and (ii) integration of operation and maintenance activities within the project system so that envisaged project out puts dunng planning and design phases can be materialized The institutional and liaison aspects of the project has been dealt with a separate study as reported in section-l appendix 15 of the project feasibility phase report However for tne sake of completeness and to establish proper relationships between the management and O & M activities of the project under consideration important aspects of this report are summarized and presented in this report 1.4 Methodologies The methodology used in developing O & M manual for Bale-Gadula project include (i) review of documents from previous undertakings and (ii) to deal more deeply into the project system as identified in the detail design pnase of the project 1.5 Report Outline The first chapter including this section deals with the general water management principles and/or practices the objectives scope of the report and methodologies used in developing this 0 and M manual Chapter 2 of this report is designed to deal with the general and basic features of the project Chapter-3 deals with the project management aspects as summarized from the institutional studies report labeled as Section-I annex-15 Chapter-4 specifically deals with basic soil-water-plant relationships including the soils ano water relationships of the Bale-Gadula command system Chapter-5 is dedicated to deal with the pnnciples of project operation and develops guidelmes/procedures for operation aspects of the Bale-Gadula command system Chapter-6 to Chapter-9 deals witn the inspection and maintenance aspects of the project under consideration WWDSE Addis Atiaoa ia Association with iCT Jd ana AB~E DLC -3- Derail Design of Bale Gaauia Irrigation & Drainage Project October 2 JI ’Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I. Volume - VII Operation and 2. 2.1 BALE-GADULA IRRIGATION & DRAINAGE PROJECT (BAGIDP) Description of the Project 2.1.1 Location BAGID project is administratively located in Bale administrative zone of the Oromia National Regional State (ONRS) Goro is the project woreda and the Goro town the capital of the woreaa is located 82 km East of Robe town which is currently identified as the capital of Bale zone Robe is located 380 km from Addis Ababa in a general South-Eastern direction via Asela (a town located 175 km from Addis Aoaba & capital of Arsi Administrative zone) Goro town is located 494 km from Addis Ababa, the capital of the nation The proposed weir site is located 9 km from Goro town in its general north direction The command area is located on the left bank of the Weybnver The command area is bounded by a cnain of ridges as local mountains (above 2000 masl) in its genera north direction The command area circumscribed by Weyb River from its general south and south eastern direction The project area is also circumscnbed by a chain of ridgs having an altitude of above 2000 masl on the right bank of the Weybriver A very long and narrow low-lying plain area (1800 masl and around) is created in between the two chain of ridges which is currently envisaged as the command area for BAGID project Geographically the project command area is located extending from 7°6'N to 7°9'N and 40°18 E to 40°37’E. 2.1.2 Altitude. Climate & Hydrology Altitude: The altitude of the river bed at the proposed weir site is approximated at 2073 50 masl The command area starts at an altitude of 2060 00 masl and extends to an altitude of 1580 masl in its downstream tail The narrow elongated low-lying valley, where the entire command area is located in, has a total length of about 35 km Climate: The project hydrologist as part of the project studying team has conducted a separate study for the climate and engineering hydrology component of the project Climate studies relevant to irrigation design works is summarized and incorporated here for quick reference purposes There is one meteorological station located at Goro town, available in tne vicinity of the BAGID project area This station records rainfall and temperature events only Another nearby station is the Ginir meteorological station located some 30 Km from the command area. The later station is observed to be Class-A type that records RainTall, temperature wind speed relative humidity, and sunshine hours at a daily time scale The climatic data recorded in these two stations were used for the design parameters irrigation system and headwork According to Thornthwaite s classification witn moisture and aridity indexes of 48% and 19% respectively climate in the project area (indicative only) is classified to be moist climate of class B type with moderate summer and winter water deficiencies Monthly moistuie deficit-surplus computation of the project WWDSE Addis Ababa in Association with -4- Detail Design of Bale Gadula ImgStion & Drainage Project tC'f Pvt Ltd andABCEPLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - /, Volume - VII Operation and Maintenance Manual area indicates that only three months (April May and October) are observed to be moisture surplus months Mean annual rainfall (2001 to 2007) at Goro station is computed to be 845 mm and mean annual PET for the same period is estimated at 1525 mm, indicating evaporation is nearly double of the mean annual rainfall in the project area Rainfall distribution is bimodal type with two distinct peaks in April and October The Belg season extends from Feb/March to June and the Miher season extends from Aug/Sept to December January February and July & August are considered to be the driest months in the project area Nearly 55% of the annual rainfall falls in the Belg season and 45% falls in the Miher season Daily rainfall records at Goro station from 2001 to 2007 is observed to be scanty and incomplete It has been assumed tnat the PMU shall collect better data for use in the operation phase of the project and decided not to put this data as an annex for this report Mean monthly rainfall Goro station for the given period is however presented in Table 2.1 Table 2.1 Monthly Rainfall Senes at Goro Observation Station I Year Jan Feb Mar Apr 2001 0 00 0 00 74 07 78 64 May Jun Jul Aug Sep Oct Nov Dec Annual I 110 80 55 50 1220 75 00 220 80 105 90 59 40 29 60 ' 821 91 2002 30 60 0 00 151 20 147 20 | 56 20 0 00 19 10 0 00 151 60 333 20 2 20 85 00 976 30 2003 0 00 0 00 3 50 19120 98 10 4 00 37 50 12 70 32 60 52 80 35.60 | 89 30 557 8C 2004 187 80 0 00 38 00 203 70 2005 1060 1890 201 10 54 60 83 80 11 30 1390 30 50 30 50 22 20 59 80 28 30 710 30 199 30 2020 29 40 6 90 72 00 134 80 70 80 0 00 | 818 60 2006 0 00 31 00 118 30 249 70 | 158 70 59 30 OOC 125 90 181 20 214 20 36 80 2 00 1177 10 2007 21 63 0 00 57 28 155 85 105 82 69 58 16 90 39 91 99 89 145 05 65 70 69 16 846 77 Mean 35.80 7 13 91 92 154 41 116 10 31 41 18 43 41 56 11266 144 02 47 19 43 48 844 11 STDEV 68 08 12 67 68 77 69 06 48 00 29 11 12 15 44 94 7403 104 41 24 06 37 75 195 53 HVI(%) 190 15 177 67 74 81 44 73 41 35 92 66 65 93 108 14 65 72 72 50 51 00 86 81 23 16 Source Weimel Yadot and B Gadula Project Office M Hydrologic vanability of rainfall in the project area is observed to be considerably high Mean annual variability index is estimated at 24% Seasonal variability is estimated to be more than 70% both in the Belg and Meher seasons According to the research outputs of NMSA (NMSA, 1996) places in Ethiopia with mean M annual variability index exceeding 20% is prone to draught Places with variability index greater than 30% are cnaractenzed with prominent draught events more frequently According to the FGD discussants of the project area one time good M ■ rainfall year is normally followed with two bad years rainfall time According to their definition a good year is characterized as a year having at least 40-days rainfall in each growing season Similarly the bad year is also characterized as a year with only 10 or less day s rainfall in eacn growing season The plot of mean annual rainfall ano annual series indicates (hat out of the 7-years (20C1 tO 2007) recoding period only three years are observed to nave annual rainfall slightly exceed.ng the mean annual rainfall The balance is observed to have an annual kWVDSE Addis Ababa in Association w/ih 5- iC z_rc/ and A5CE LC D Desiqn o' Bale Gariuia Irrigation & Drainage Project October 20*Ministry of Water and Energy - i-eaerai Democratic Republic of Ethiopia Operation and Mointe^^^^g^^^^ Section - /, Volume - VII rainfall of less or equal to the mean annual rainfall Annual rainfall less than the mean annual rainfall is prone for moisture stress Mean annual daily maximum temperature is estimated at 29°C with a mean annual minimum daily temperature of 15 7°C May and October are humid months with above 74% relative humidity The area has mean annual relative humidity of 70 3% Wind speed is highly variable ranging from 166.5 km/day in April to 75 2 km/day in October Mean annual wind speed is estimated at 102 2 km/day At 3.1 sunshine hours/day cloud coverage in the project area is maximum in Juiy. ana at 9 6 sunshine hours/day it is minimum in December Mean daily sunshine hours in the project area is estimated at 6 4 hours/day Hydrology & Water Resources: Weyb nver is the only available water source in the project area The command area circumscribed by river Weyb in the general south direction The hydrological observation station Weyb is located at the Goro-Gimr mam road bridge situated d/s of the proposed diversion site Recording has been made since 1984 and mean daily hydrograph data from 1984 to 2004 are available for the study of the BAGID project At mean annual runoff of 385 mcm tne mean annual inflow for the Weyb watersned is recorded to be 12 16 m /s/day Mean daily minimum monthly inflow J is recorded to oe 0 95 m'/s/day and it appears in January The mean daily maximum inflow at 34 2 m*/s is observed to happen in August. Hydrologic variability index (HVI) is observed to be considerably high It is nearly 40% for the annual senes and more than 80% for the Belg and Meher seasons These features of tne Weyb watersned hydrograph are given due emphasis in this intenm phase and dependable flows available for 80% of the time has been used to plan crop and imgation water requirements of the project area. Tne dependable base flow was computed by the project engineenng hydrologist These are available at Table 2.2. Table 2.2 : Mean Monthly Inflow (cumecs/ Series of Weyb River at Alem-Kerem Gauging Station 7----------------------- -------------------------r YEAR JAN 1984 2 536 FEB MAR APR MAY JUN JUL AUG SEP OCT NOV OEC --------------- 1 1 664 1 564 2 260 8 816 7 269 1 176 r 1 494 27 055 84 106 3 793 | 16 V0 37 170 67 905 ' 13 654 3 580 2 091 1985 1 422 17 388 71 548 34 317 38 975 10 779 2.786 Annual Mean 13 723 24 570 1986 1 503 1 280 3 788 | 32 794 54 979 52 432 60 424 , -J 33 867 82 898 43 517 6616 5 317 — 31 618 1987 3 878 1 379 13 576 56 294 80 605 i 23 965 3 498 10 422 1988 0 441 C486 0 923 23 823 5 323 2 704 64 428 150 081 •989 C649 0 589 i 0 990 J 71 136 28 809 2 991 57 141 37 609 28 363 84 953 42 914 38 578 12 640 1 274 22 873 127 393 6 120 1 128 38 984 ■ 990 9 563 33 692 55 459 79 403 6 957 , 1 670 30 557 96 258 28 231 ———___ 55 770 24 041 31 615 29 521 47 173 4 463 4 211 33 053 | ------------- - ’991 0 983 1 296 2 220 ’9 204 29 875 —L-------------- 1 15 957 1 5 e2i i 16019 176 844 65 732 10 968 90 059 101 686 3 427 18 300 8 007 I 1 549 23 965 1992 0 "74 4 169 1 0 620 1 396 — 118 044 — 29 668 33 282 39 002 WWDSE Addis Ababa in Association with -6- /C P^t Ltd ind A9CE PLC r Deta'I Design of Bale Gadula Irrigation & Dramagf Project October 2011Ministry of Water and Energy - Section - I, Volume - VII Federal Democratic Republic of Ethiopia__________________________ Opera bon and Maintenance Manual i 1 YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV — DEC i 1993 1 13012 104 604 4 922 8 652 40 564 20 915 11 930 46 117 59 501 55 286 48 281 1 486 1994 0 642 0 426 0 439 24 430 7 488 I 3 120 58 379 281 928 47 632 79 366 100 801 7 333 Annual Mean ---------- 34 673 1 1 51 003 ] L”9? 0 926 0 521 4 805 54 259 25 123 3 773 20 838 97 928 64 696 106 631 13414 1 943 32 905 1996 2 325 0 926 1 525 7991 53 022 69615 | 79 324 105 481 52 081 28 755 2 197 1997 1 141 0 798 0 810 14 565 20 125 27 548 25 467 91 248 188 008 96 785 37 427 1 499 3 3 728 26 155 44 173 | 1998 -- 1 303 0 098 7 543 23 583 2 354 48 186 123 075 110 022 61 206 258 926 _________ 27 724 1 539 55 463 [ 1999 0 994 0 631 3 878 6 542 0 697 0 500 0 496 1 920 1 474 3 719 21 8H 112 759 1 047 0 493 2 333 31 292 5 174 C649 i 582 15964 11 594 2 592 63 435 71 000 31 604 49 260 8618 2 799 21 079 ! 2000 2001 2002 2003 24 529 1 827 | 20 660 82 639 56 530 174 813 28 005 5 265 33 157 31 807 197 290 30 606 69 657 87 518 7 322 5 248 3 543 16 476 16 857 67 016 15 136 2 764 53 463 12 740 1 620 16 477 9.62’ j 8 878 9 877 46 954 107 708 29411 34 839 4 569 18 185 2 3 649 , 2004 1 701 ■404 ] 0 465 | 25 983 24 787 2 464 ’ 27 945 83 267 j 64 544 55 942 4 216 3 675 24 699 j avg 2 475 '643 6 252 30 524 27 287 i 24 003 | | 40 06’ 91 809 55 993 72 465 18 949 8 208 32 ’39 I STDEV 3 22 23 34 12 39 29 01 23 60 4.4 11 30 98 58 98 37 12 59 41 22 75 1040 12 08 HVI(%, 130 09 305 41 | 198 23 95 05 86 49 ’83 78 I 77 32 ‘ 64 24 66 30 81 99 120 04 126 70 37 58 MCM 6 630 18 492 16 745 79 118 73 085 62 216 ’07 300 245 901 1 145 134 194 090 49 115 21 985 1019 809 Source Weimei Yaaot and B Gaduia Project Office 2.1.3 Basic Agricultural Features of the Project Area Land Tenure System: By proclamation in Ethiopia, land remains to be a public and government property The farmers have use right and also to inherit for their descendants On the Dasis of data collected from a small random sample of 98 farm holdings in the project command the size of holdings varies from 0 5 to above 3 1 ha Nearly 60% of the respondents have land holdings that vary from 2.1 ha to 3 0 ha per household followed Dy 25% with holdings of 1 1 ha to 2 0 ha Only 50% has less than 1 ha Crop Production and Food Security ConditionszThe existing status of crop production cropping system and farming system scenario of Baie Gaduia irrigation command was studied through a comprehensive questionnaire consisting of all production parameters These questionnaires were completed Dy personal contact and througn Kebeles of the selected woredas for collection of primary data The secondary data on land use, area and production of crops along with inputs distribution were also collected from agncultural and rural development offices of woredas and Bale zone under which the present irrigation project falls From this study and data collected it is quite evident that the yield of maize per hectare (13 3 qt/haj is lower than the average yield recorded at the national level and it is lower than the yield obtained at regional level The total hectare under wheat is the mghest followed Dy Teff and barley Rice has not been introduced m Goroworeda The area and production for some of the crops ano commodities under project command are not available though they are being grown The WWDSE Addis Ababa tn Association with -_F- Dera».‘ Des'qn of Bale Gaduia irnqation & Drainage Project IC^ Pvr Ltd and ABCE DLC Octobe' 20.'Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I Volume - VII Operation and Maintenance jManyal trend of crop production of the individual farmer in their holding for the last 5 years has shown an increasing trend as have been indicated by 93% of the sample farmers during the interview The food production of last year was insufficient by 59% of the families interviewed during the survey The major reason recorded was bad weather condition of the season and shortage of inputs The coping mechanisms to fill the food shortage gap are labor sales of the family members sale of livestock remittance from other people, aid from government and NGOs borrowing and sales of forest products, out of the sales of live stocks is the first The data generated have also revealed the requirements of food crops per a farmer HH per annum Hence, the maximum requirement being 75 qt whereas the minimum is 6 qts while the average is 23 qts per farmer house hold Existing Status of Farming System: Several natural factors influence the farming system of the project command area Among these the altitude, soil and climatic parameters are the major factors The rain fed crop cultivation integrated with livestock rearing is the principal farming system in most part of the project command The proiect command is sparsely populated with a few small holders hence major portion of land is yet to be cultivated However on the basis of the statistics available from the related woreda, the presently cultivated area is under wheat (32%). followed by black cumin (21 7%) and Teff (10%) The woreda. on the other hand, has got many mechanized farms with large and small holdings ano tnese data were not used in crop budget and planning computations Major Production and Development Constraints: Bale Gadula irngation command is very thinly populated witn a very low cropping intensity A lot of potential land is still left uncultivated The crop production technologies are still very traditional though mixed farming system is common in the area In crop production there is very limited introduction of modern inputs like fertilizer improved crop vaneties, quality seed and agro-chemicals Moreover different natural hazards such as recurrent drought condition, land degradation due to erosion and rapid deforestation hail and frost damage flood and drainage problem etc have resulted in poor yield in both project command area. Though extensive area is not yet being used for agricultural activities due to low population the government is active to arrange the resettlement of more farmers by promoting the resettlement scheme to bring more land under cultivation During socio-economic household survey a numoer of production constraints have been identified Out of these, the most important factors include (i) inadequate input supply (h) low and/or absent of using improved verities (iii) poor seed quality (local seeds are predominantly used), (iv) low input utilizations like fertilizers due to lack of knowledge inadequate distribution system, high cost shortage of agricultural credit & poor extension with research activities etc (v) less or no use of agro-chemicals (vi) traditional level tarm implements still in use (vii) shortage of draft power (vm) drainage problems (ix) natural hazards (x) WWDSE Addis Ababa in Association with -0- Detail Design of Bale Gadula Irrigation & Drainage Project iCTo r Lfd v'-r v pLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I, Volume - VII Operation and Maintenance Manual poorly developed research-extension linkage (xi) inadequate extension services (xii) marketing, health problems etc 2.1.4 Existing irrigated Agriculture Practices No existing irrigated agriculture practices in the project area for Bale-Gadula Project 2.1.5 Potential Command Area of BA GID Project During the Inception and Interim phase a surveying work for the command area has been conducted and base map at a scale of 1 10,000 has been prepared Detailed layout design for the irrigation system has been completed accordingly According to this layout design work the gross command area for BAGID project is estimated at 6155 na with a net command area of 5150 ha (17% loss for road and both supply & drainage canal system) Soil and land suitability base maps have been prepared The detailed layout design has used these maps as a base map for fixing the boundary of the command area 2.1.6 Crop Planning and Cropping Pattern Agricultural planning activities for the project include crop selection ano designing of tne cropping pattern ano establishing of crop factors to be used as a design parameter for computing crop water requirements Crop planning and cropping pattern design works are performed by the senior irrigation agronomist of the project Crop Planning: An essential element of tne objectives of crop planning is not only the maximization of tne benefits through various inputs that go in the agriculture - the land water human resources etc but also an improvement in the economic situation of the people of the area The important requirement of crop planning is not only from the point of view of balancing production with demand curves but also from the point of view of trying to use planning as a method of correcting difficult situations like failure of a particular group of crop to be offset by producing other crop of the same group subsequently to meet the requirement of the people Hence the purpose of crop planning should also be to help overcome the problems arising from adverse seasons In an economic situation, which is developing as a result of fast growing population, nsing aspiration of people and iand going out of cultivation for various other uses like roads, bndges, factories, homes etc where there is continuous loss of land from agriculture crop planning Decomes very important Production physiologists all over tne world are busy analyzing wnat are the maximum possibilities under a given agro-ecological condition from the point of view of per day productivity The strategy will vary from crop to crop Crop planning also tries to help to overcome the serious effects of adverse weather on agricultural economy of a country wnich has so many dependents upon agriculture not only for its food supply but also for its employment and its income Naturally it cannot afford to take risk and create conditions where serious fluctuation in production might occur year after year WWDSE Addis Ababa in Association with -9- Detail Design of Bale Gadula imoatior. & Drainage Proje P •C P, t Ltd :! AE LC r October 2S ’Ministry ot Water and Energy - Federal Democratic Republic of Ethiopia Section - /, Volume - VII Operation and Maintenance Manual Presently, there has been positive trend of switching over the vaneties which are relatively insensitive to photo-period and temperature This provides with a considerable amount of flexibility in handling the material Although the photo sensitive crops are also very useful in certain situations Hence, it is better to have both kinds of materials Sunflower is one of the examples that can be grown year round In crop planning the main considerations to be given are • The soil of the project command • Climatic condition of the area • Cost, income and risk involved in growing crops, • Capital, labor and other resources availability, • Special needs of the farmers - home requirement of food grains, fodder for cattle etc • Scientific advances made through research Crop management is tne judgment ana decision making on how best the present way of cropping can be suitably modified so as to give best results desired It requires efforts to integrate resources technical knowledge and expenence to maximize profits It snouid be done taking farmers into confidence to consider alternatives to prepare best cropping Dian tu suit the conditions with optimum utilization of available resources. Criteria for Crop Selection The choice of a crop for a particular area under irrigated agro-eco-system is dependent on its potential response to irrigation location specific environmental conditions, socio-economic situation, marketability and expected profitability The climatic parameters determining the choice of a crop are temperature sunshine or radiation, wind speed relative humidity precipitation and evapo-transpiration Like climatic factors, the physical, chemical and biological characters of soil and soil depth also have direct influence on the performance of a crop The crops widely vary in their response to imgation Therefore, under the irrigated agro-ecosystem with assured availability of water the efforts are made to select the most economical high yielding and highly irrigation responsive crops which fit well in the production system with high degree of input- use- efficiency eco-friendly and helping in sustainable agnculturai production The crops like vegetables fruits rice wneat and maize are highly responsive to imgation while some of the legumes/pulses and oilseeds respond moderately On the other hand crops like Teff and barley have ability to tolerate drought but show only marginal response to imgation and other inputs Besides the above factors the present land use social considerations liking of the farmers their attitude and ability to successfully cultivate a particular crop also determine the choice of a crop and cropping pattern The Cropping Pattern. The cropping Pattern proposed is given in Appendix-I for irrigated production system on the basis of altitude, agro-climatic parameters WWDSE Addis Ababa in Association with 'CT Pvt Lfd ind APCE PLC -10- Detail Design of Bale GaOula Imgation & Drainage Pro/ect October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual and land suitability In general a soil depth of more than 100 cm is suitable for all the crops recommended for cultivation in the project area The introduction of high yielding photo-insensitive dwarf varieties of rice and wheat and high yielding medium duration hybrids and composites of maize have been proposed to be grown in rotation of cereal - cereal The project command is also suitable for cereals The above proposed rotations should have proper intermix of legumes and pulses oilseeds vegetables forage crops of short duration etc instead of long duration low yielding traditional vaneties which are being grown in the existing farming system The above cereal-based rotations in the cropping system will be able to provide adequate food grains due to their 4 to 5 times high yield potential with optimum production inputs The proposed crops like maize wheat, rice etc are already being grown by a few farmers in the command area, which indicates the suitability of climate and soil for these crops Since these crops suffer due to moisture stress during dry season the imgation would help to provide need-based moisture and encourage the use of other inputs for their high productivity In areas with dominated Vertisols type water logging problems especially in long wet season is reported Such areas are proposed to be cultivated with high yielding vaneties of nee having fine long grains for increasing the food grain production and to contain the rice import to the country Wheat is another important cereal crop already being grown wherever moisture is available Since, the soil and climate are favorable for its growth the intensification of crop in larger hectare by introducing new varieties of bread and durum wheat responsive to nutnents and water would enhance the productivity at least 4-5 folds as compared to sorghum and Teff Since maize is already an important and productive crop of the project command the replacement of local variety witn full season (90-110 days duration) hybrids and composites with high yield potential and better nutritional value will fit very well in the proposed cropping pattern To maintain the sustainable agricultural production, it has been proposed to grow pulse crops, oil seeds and vegetables as a pan of the cropping pattern In the existing farming system of command mixed farming is a common feature This is dominated by cattle followed by sneep This system of mixed farming need to continue, hence the cropping system includes the perennial legumes and grasses to support the livestock with nutritive feed along with other feed resources to enhance the production of milk and meat and also to provide encouragement for product preparation and agro- mdustries. The aoove proposed patterns are in line with the current policy of Federal Government of Ethiopia on agriculture nas given in the former section of this report to attain the self-sufficiency in food production, full and efficient utilization of land and water resources and maintain environmental and ecological balance while attaining maximum agricultural production potential The yield is likely to De improved further by introduction of improved tools and bullock-drawn implements for timely field operation in phases This type of partial mechanization would improve the efficiency of labor force reduce their drudgery and also boos* the rural based agro industries generating more employment opportunities This will help in improving tne economic situation of the people by vVWDSE Addis Anaba in Association with -11- Detail Des'qn of Bate Gadula irrigation 4 Drainage Protect 13"'J “BCE October 201'Ministry of Water ana Energy - Federal Democratic Republic of EthiopiaOperation and Mdjntena/jQC Manual Section - /, Volume - VII providing better nutrition and marketable surpluses at the same time provide healthy environment Length of Growing Period (LGP): Length of Growing Period (LGP) for crops is very much correlated with climate largely impacted with temperature The low altitude of the area (above 1800 masl) and farmers practice in the existing both rainfedS irngated agriculture are given due emphasis to fix LGPs of each crop in the cropping pattern In addition the expenences of FAO (1998) was also used as a pnncipal guideline for fixing LGPs FAONo-33 was thoroughly consulted while fixing LGP for each crop in the cropping pattern of both scenanos Adaptability of crop type to the prevailing condition of the project area was also factored by giving the expenence of both farmers and the woreda agnculture office into account Crop Factor (KJ: - The effect of crop on its water requirement is represented by crop co-efficient (Kc) This is presented by the relationship between reference Evapotranspiration (ETo) and crop evapotranspiration ET^ or ETC as ET^ = c a The values for crop coefficient vary with the crop, its stage of growth, K ET growing season and prevailing water condition. The second step is required to select suitable values for crop coefficient The crop coefficient (KJ value of a given crop is dependent on (i) crop type reflected in the morphological and physiological charactenstics of crops, leaf area coverage (u) soil evaporation that depends on moisture availability, soil physical characteristics ano crop leaf coverage, and (iii) on the growing stage of each crop tnat again depends on crop coverage and the Leaf-Area-Index that affects stomata conditions of crops The three K< values of a crop are characterized as (i) Initial stage which takes the whole growing period until the crop gets 10% ground coverage, (ii) Crop Development stage that includes the growing period by which crop leaf coverage reaches 10% to 80% and (iii) The Late growing stage or the harvesting period at which the crop development is at its late stage Crop coefficient selection for the crops in the proposed cropping patterns (both scenarios) has been made giving the aforementioned factors into consideration FAO No-56 and 33 are thoroughly consulted to fix crop coefficients at various stages of each crop in the cropping pattern Kc value for each crop is estimated based on the growing stage of the crop to account the impact of crop type in its Kc values The impact of the soil evaporation as it is accounted in the computation of CWR is schematized in Figure 2.1 WWDSE Addis Ababa in Association with ICT &v! Ltd ’nj ABCE pL~ -12- Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Ministry of Water and Energy - Federal Democratic Republic of EthiopiaOperation and Maintenance Manual — Section - /, Volume - VII Figure 2.1 rSchematics of crop coefficient as impacted with soil /------------------- > Wet Soil Surface ___ J l/n ___ </ \ Soil Evaporation xx ✓ Dry Soil Surface v ' ' '------------- Trancnira hnn IKrhi -O’" - evaporation & Leaf Coverage Both the LGP ano K s of each crop in each growing stage are presented in the following subsequent tables (Table 2.3 and Table 2.4) TaDle 2.3 : Length of Growing Stages (LGP) of proposed crops /days Len gth of growth Pe riod (LGP) /da ys Total Remarks No Crop Initial Development Middle Late days/ 1 Wheat 15 25 50 30 120 2 3 — Ricei upland) 15 25 50 30 120 J Maizet Seed) 20 40 50 30 140 Sept-Dec 4 Maizet green) 20 45 25 10 100 Mar- June i 4 5 H bean 15 25 40 20 100 Soya bean 20 -------------1----------------- 30 45 25 120 1 6 Sesame 15 35 60 20 130 7 Ground nut 25 35 -------------- 40 20 120 9 Onion ( Bulb) 15 25 55 25 I no H-----------------------1 10 Red pepperi dry) 15 35 55 25 130 11 Sugar cane 55 90 120 100 365 WWDSE Addis Ababa in Association wt*h -13- '07 Pvf _fg , • Detail Design of Bale Gadula irrigation & Drainage Project October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I, Volume - VII Operation and Maintenance Manuel - — — Table 2.4 : Crop Factor in Crop Development Stage I No Crop Early growth stage/Kc Mid stage/Kc Late stage/Kc 1 Wheat 0 30 1 05 02 2 Rice 1 10 11 0 95 I3 Maize(green) 0 30 1 05 0.55 4 Maize (seed) 0 30 1 05 0 55 5 H bean 0 30 1 04 6 Soya bean 0 50 0 75 0.35 7 sesame 0 30 1 05 0 35 8 ground nut 0 40 0 95 0 55 9 Onion (bulb) 0 30 06 0.25 10 R Pepper ( Dry) 0 40 0 65 04 11 Sugar cane 0 60 11 13 12 Citrus 0 60 11 13 13 Mango 0 70 1 09 13 Alfalfa 0 40 0 95 04 2.1.7 Soil and Land Suitability 2 17 1 Landuse & Land Forms Land Forms.Base on slope is tne upper plain regrouped into three classes i.e nearly to level land witn slope gradient 0-1% very gently land with in slope range 1-2% and undulating sloppy land wit with slope gradient 2-4% 2 17 2 Soils Physical Charactenstics Parent Material The soils of command area predominantly developed on alkaline olivine basalt and tuffs rhyolitees of lower Tertiary Trap Series by alluvial, colluvial and in situ weathered process of basaltic parent material Effective Soil Depth Rotting conditions are controlled by soil effective depth and ease of root penetration It is an important property for evaluating soils agricultural property The soils whicn are found in the project area, are categorized in to snallow moderately deep, deep and very deep The maximum depth ranges from 4 5 to 5 meters and the minimum depth is 25-50 cm deep to very deep soils are mainly found in almost land of the command area While shallow to moderately deep soils are situated gently to sloppy land Most of the command area lies under very deep depth (>150 cm) category Soil Coiour:Soil color is the most perceptible Taciai appearance of the soils that can be without difficulty known by any person It is related to precise chemical physical and biological properties of tne soils The well drained soils of the study area have a color of dusky red Nitisols and dark reddish brown Luvisols while WWDSE Addis Ababa in Association with -14- ICT Pvt Ltd and ABCE p' C Detail Design of Bale Gadula Irngation & Drainage Project October 20 nMinistry of Water and Energy - Section - /, Volume - VII Federal Democratic Republic of Ethiopia________________________ Operation and Maintenance Manual the soils with imperfect drainage system are black and dark grey to grayish brown m color (Vertisols) Soil Texture: Soil texture implies relative proportion of sand, silt and clay in the fine earth fraction the soil material smaller than 2 mm in diameter It has been described by feeling method in the field and by hydrometer method in the laboratory The overall textures of the investigated soils vary from sandy clay loam to clay on surface soil While in subsoil varies from loam to clay The result of laboratory analysis showed that the clay on top soil varied from 29 4% to 73 57%, with an average value of 49 12% The clay content increases in sub soil and ranging from 11 98% to 84 85% with mean value of 67 27% The sand content top soil of sand is ranging from 9 62 to 53 76% with an average of 31.26%, while in sub soils it decreased and ranging from 9 50 to 52 74% with an average of 20 44% The silt content in top soil is between 6 48 and 55 54% where as its content decreases from 2 13 -62 37% with an average of 12 29% Soil Structure: In the project area the top soil being black and dark gray colour (Vertisols) are charactenzed by granular or blocky structures and moderately developed fine and medium singular or strongly developed prismatic structure at subsurface In tnese soils there is no hardpan or cementing materials in the surface and subsurface soil and as sucn compaction will not be a problem under careful machinery operation planning However, the upper layer of soils with red and ^eddish brown including Luvisols have weak granular structure while the subsoil have moderate ano medium sub angular blocky structure Consistence: Consistence refers to the 'esponse of soil material to applied force or pressure The Vertisols are hard when dry. very firm when moist and very sticky and very plastic when wet. whereas the reddish to reddish brown clay soils (Nitisois&Luvisols) are hard when dry and very friable to friable when moist and slightly sticky and slightly plastic when wet Surface Cracks:Surface crack has been observed in most surveyed areas Gene, ally surface crack is a clay texture characteristic However it is a typical characteristic of swelling ciay soils (Vertisols) According to the field observations the width of cracking ranges from fine (<1cm) to wide (2 to 10 cm) Bulk Density:Bulk-density of a soil is the weight of a known soil volume compared to tne weight of an equal volume of water or weight per unit volume Bulk densities above 1 75 g/cm2 for sandy and 1 46-1 63 gm/cm3 for silty and clays are quoted as causing hindrance to root penetration Generally in normal soils bulk density ranges from 1 0-1 65 g/cm’ In very compact soils sometimes it goes up to 2 0 g/cm To measure bulk density of the soils in Bale-Gadula irrigation project area undisturbed soil samples taken by using PF core sampling cylinder were sent to Son Laboratory The sub-soil bulk density of the soils is 3 between 1 01 and 1 80 g/cm tne average value being 1 50 g/cm While in substratum it vanes from 1 17 to 1 94 g/cm with an average of 1 59 g/rm 2 3 ✓VWDSE 4 ba n Association with T : Fvt .U j - r ' ? -15- Derail Design of Bale Gadula irrigation & Drainage Project October 201 *I Ministry of \A/ater and Energy - Federal Democratic Republic of Ethiopia 2 17 3 Hydraulic Features of Soils Section -1, Volume - VII ag Drainage The moisture condition of the Vertisols was slightly moist in topsoil up to 30 cm deep but increasing downwards while other type of soils were dry and slightly moist The soils of upland and the hills are somewhat excessively drain (Leptosols) and well drained (Nitisols and Luvisols) The ground water table of the investigated area is very deep and there is not any record of occurrence of flooding in the area infiltration Rate:lnfiltration rate refers to the measurement of vertical intake of water into a soil surface and it is important parameters in design of imgation system and soil conservation The results are also used for determining the most efficient metnods of applying irrigation and making runoff calculations The measurement of infiltration rate was conducted by using of double nng infiltrometer method which is desenbed in the FAO soils bulletin 42 It is the rate at which water enters the soil surface under given conditions It is measured in the field for representative soils, generally using the Double-nng infiltrometer method Infiltration is important for selection of suitable methods and design selection of irrigation type calculation deep percolation losses irngation efficiencies and crop water management In the case of present worx the rate of infiltration rate is ranging from 0.9 to 7 8 cm/hr with an average value of 2 86 cm/hr, showing that in most cases the result is witnin the optimum range except at site profile pit RGP-02 only (see Table 2.5) Hydraulic Conductivity The soil hydraulic conductivity or permeability refers to tne ability of a soil to transmit water through its oody vertically as well as honzontally it was measured by using the Inverse Auger-hole method test described in the FAO soils bulletin 42. The overall result of the hydraulic conductivity varying from 0 17 (slow) to 1 3 m/day (moderately rapid) and its mean value is 0 65 m/day (moderately slow) (see Table 2.5) Table 2.5 : Summary of Infiltration Rate and Hydraulic Conductivity Measurement Profile Code Texture Mean Infiltration Rate (cm/hr) HC (m/day) BGP-02 Clay Loam 78 0 04 I BGP-18 clay 2 3 0 1 BGP-34 clay 33 0 12 BGP-35 clay 09 0 07 BGP-39 clay 1 00 0 11 8GP-48 Clay 0 04 11 BGP-53 Clay Loam 3 1 0 06 BGP-68 Clay Loam 51 0 07 •WWDSE Addis Ababa in Association wiih -16- Detail Design of Bale Gadula Imgation & Drainage Project ICT Pvt L>d and ABCE PL C Orlober 2Q,, I I V I I p I I I I I I R I I R R HMinistry of Water and Energy - Federal Democratic Republic of EthiopiaOperation and Maintenan<anuBl — Section - i^yolume - VII Field Capacity: The field capacity value of the soils in the command area varies from 36 07 to 58 23% Permanent Wilting Point (PWP): The PWP of the project area ranged from 20 36 to 43 75% Available Water Capacity (AWC): Available water capacity (AWC) is the volume of water retained between field capacity and permanent wilting point. AWC was computed using the following formula (F^ - PU P) v horizondepth x BD A U 'C = ---------- ---------------------- - ----------- 100 Table 2.6 snows the average available water capacity (AWC) and readily available water capacity (RAWCj value and textural relationship of soils of the study area The value of available water holding capacity and readily available waler of soils within the study area m most cases are at moderate to very high level Thus in terms of water holding capacity most of the soils are suitable for irrigation Table 2.6 : Soil Moisture Characteristics Curve & Available Water holding Capacity of the SMUs Study Area - BaleGadula Supplier WWDS Enterprise FC(0 33)Bar FC(1 OjBar AW Computations i Field No Depth (cm) FC(3.0) Bar I r FC(4 2)Bar lAB NO 258 V09 2582/09 2583/09 PWP(15.0) Bar %(Wt) BGP 05 60-100 47 63 100- 160 46 77 %(Wt) %(Wt) %(Wt) %(Wt) 44 82 40 89 36 31 28 77 43 86 39 79 35 06 28 73 35 49 34 *8 32 56 30 22 34 91 33 67 32 02 2861 185 TAW (mm) , 295 2 0-50 38 23 2584/09 BGP- 50-100 37 27 34 2585/09 2586/09 BGP 2587/09 68 2588/09 BGP- 2589/09 35 2590/09 86 100- 15C 37 76 36 23 33 15 31 02 0-50 57 76 52 19 49 25 45 75 50-100 58 23 52 17 47 11 43 75 28 67 43 75 39 81 0-50 48 34 43 56 42 69 “1 39 18 37 39 50-100 57 98 49 28 45 17 42 46 r 162 153 128 8 I I 162 15 I i 152 55 0-26 40 15 37 48 33 90 31 97 2591/09 2592/09 2593/09 2594/09 2595/09 2596/09 2597/09 2598/09 Average BGP- 18 26-77 42 94 36 07 35 15 33.19 77-160 36 19 33 33 29 96 28 38 38.42 29 58 29 94 114 182 88 j 25 47 BGP 48 0-30 43 46 40 78 37 77 35 00 3247 30-60 53 30 11X47/ 1 r 88 11 i____ j BGP- 53 0-30 45 05 30-70 48 33 0-30 36 07 47 64 41 18 38 99 34 92 41 60 37 98 35 63 33 15 43 80 41 32 ( 4C 81 36 14 34 O' 30 42 24 52 20 91 35 17 31 37 26 G7 20 36 1iZoUn 84 315 1 BGP 39 30-70 I 37 24 IQV I 112 14 0 - 160 45 2 41.2 38 1 35.1 31.5 136 3 204 5 IAWDSF Addis Ahatia in Association with -17- Detail Design of Bale Gaduia Irrigation & Drainage Project !C~ ’ ^ta a ? ABC £ 7 Octode- 20 • 3 j> 38 3nMinistry of Water and Energy Federal Democrat*. Republic of Ethiopia 2 17 4 Chemical Properties of Soils Section - I Volume - VII Operation ond Maintenance Manual Soil nutrient status of the project site is generally moderate to high The content of organic carbon of the area is high, ranging from 0 21 to 3 91% with an average of 1 18% the soils have very high CEC & BSP and their soil reaction slightly acidic to extreme alkaline The CEC value of the project soil types is very high ranging from 3 2 to 118 33 with an average value 56 2 meq/100g soils The content of phosphorus is very low to low and the average value 2 99 ppm Supplementary phosphate will be required The total nitrogen content of the soil is medium to hign Nitrogen value is between 0 02 and 0 39%, whereas the average value is 0 1% Supplementary nitrogen fertilizer would be required Generally the content of exchangeable Ca is nigh, which ranges from 3 62 to 86 46 with average of 30 07 meq/100 grams of soil Exchangeable Mg is high, varying from 1 34 to 40 77 with an average value 9 16 meq/100 gram of soil The reserve of K is low to high (0 64 to 5 63 meq/lOOg soil with an average value of 0 648 meq/100g soil) The EC value of all mapping units is low and thus salinity will not be any problem The soil is in some cases calcareous and sodic The major constraints of the area are soil sodicity m some areas, soil erosion, dense vegetation cover and surface stoniness 2.1.8 Socioeconomic Features of the Project Area Population of a given geographical area and specific time is very important in determining elements in development planning The population in five rural Kebeies namely (i) WenaiWeyb (ii) Weltai Nagaya (iii) Bale Gadula, (iv) Bale Anole ano (v; Elamsogido falling in the command area of Bale Gadula Irrigation Project is discussed hereunder (■) WeltaiWeyb Kebie The base year population of the Kebele in 2008 is 5138 male 2538 female 2600 and the projected population from 2008 to 2030 will be 8658 male 4277 and female 4381 (ii) WoltaiNaGaya Keoie This Kebele has total population of 1962 in 2008 compnsing male 1056 and female 906 Its projected population from 2008 to 2030 will be 3306 maie 1779 and female 1527 (in) Bale Gaaula In 2008 Bale GadulaKebeie total population is 2980 male 1499 and female 1481 The projected population from the year 2008 to 2030 will be 5021 male 2526 and female 2495 (IV) Bate Anole Kebie In base year 2008 the Kebele population is 4046 male 1820 and female 2226 The projected population from 2008 to 2030 will oe 6818, male 3067 and female 3751 Elamsogido Kebie For the year 2008 this Kebeie has total population 2346 male 1155 and female 1191 The projected total population will be 3953 male 1946 and female 2007 2.2 Description of Works/Project Components The Bale-Gadula Irrigation and Drainage Project (BAGlD Project; is designed to constitute the following four major components WWDSE AMs Ababa in Association with id- Detail Design of Bale Gaaula Irrigation & Drainage Project i IC T P^l ' td ana ABCE PL C October 20i 1Ministry of Water and Energy - Federal Democratic Republic of Ethiopia (0 The Headwork Section - /, Volume - VII Operation and MamtenancBManUa!^^. <") The Conveyance System, (III) The Energy Dissipating Structures and (IV) Regulation Structures (I) The Headwork Component: This component of the project is designed tc constitute two major sub components (a) the weir proper ana (b) the head regulator The weir proper again includes the weir bay, the weir crest/full supply level, the sluice gates energ, dissipating horizontal apron located d/s of the weir bay & flood protection walls On the other hand the Head Regulator (HR) constitutes the broad crested weir as rts inlet the head regulating gate the settling basin for removal of silts and the Partial Flume in rts further d/s end as a discharge measurement structure The intake of the BAGID project is designed to be on left bank of the Weyb River The salient features of head works are given in Table 2.7. Table 2.7 : Salient Features of Head Works S.No Description Unit Weir Under sluice Head Regulator 1 River bed levei masi 2073 50 2073 70 2073 50 2 H F L (For 500 year) masi 2078 60 2078 60 2078 60 3 Afflux 5 Crest level 6 Heignt of weir m 2 60 2 60 260 masi 2076 00 2073 70 2074 30 m 2 50 0 20 0 80 7 Heignt of Clear Opening m - 2 50 2 20 8 Pond Level masi 2076 00 2073 70 2074 30 9 Lacey s waterway m 85 72 10 Waterway m 42 50 2 50 2 00 11 Thickness of Divide Wall m 1 00 12 Overall waterway m 46 00 - 13 Looseness factor 14 Discharge ------------- I Cumec 282 33 00 3 561 15 Total Discharge Cumec 315 3 561 16 Cistern Level masi 2073 20 2073 20 2073 10 17 Cistern length m 13 50 13 50 7 00 18 U/S Floor Lengtn m 8 00 8 00 2 25 WWDSE Addis Ababa in Association with -19- Detail Design of Bale Gadula imgatinn & Drainage Project IC? P\t one ABCE PlC October 20 nMinistry of Waler and Energy - Federal Democratic Republic of Ethiopia_________________ Operation Section - I, Volume - VII I---------------------- S.No Description Unit •-------------- ------------- — Weir ________ Under sluice Head Regulator 19 I---------- D/S Floor Length m 18 70 18 70 — m 26 965 20 — Total Floor Length — 21 26 70 __________ 26 70 — 075 0 75 1 75 1 75 29 215 0 50 — 22 Minimum Floor Thickness Maximum Floor Thickness m m 1 00 (ii) The Conveyance Component The main canal (BAGMC-1) located on the left bank of the river one Cross Drainage structure at Asendabo stream, 30 Secondary Canals (SCs). 150 Tertiary Canals (TCs) associated drainage canals (27 Collective drains, 300 Tertiary drains ) are all included in this component of tne project The Gross Command area (GCA) is 6155 ha and Nil Irrigable Area (NIA) is 5150 ha (iii) Energy Dissipating Structures: Canal falls designed to have three categones (i) Glacis type drop structures for drop height exceeding and equal to 1 5 m (ii) Vertical drop structures for 0 5 m < Drop Height<1 50 m, which are entirely located on tne Secondary canals of the command system (iii) Small drop structures for drop height less than or equal to 0 5m and exclusively located on the Tertiary canals of the command system and all out falls and drop structures in the drainage canals are all grouped under this component of the project (iv) The Regulating Structures: The division boxes as located at the SCs and TCs off-taking points are the major structures under this category There are 30 SCs off-taking, 150 TCs off-taking which sums up to be 180 division boxes in the BAGID project command system The division boxes are designed to constitute a simple proportional division box. complemented with gated orifices at each outlets cross/head regulators as located in the d/s reach of the parent canals and a discharge measurement provisions to serve regulation process in the system. Three types of division boxes have been provided in the canal system of the BAGID project: (i) Type-A division box that includes division boxes with two side off-taking (left ano right) In this category each division box has two nead regulators aligned to the off-taking canal side and one cross regulator located in the d/s extension of the parent canal (ii) Type-B division boxes this category include division boxes off-taking to the right bank of the parent canal and (iii) Type-C division boxes with off-taking structure on the left bank of the parent canal In each Type-B and Type-C division boxes one head regulator located in the off-taking canal side and one cross regulator located in the d/s extension of the parent canal are available AWDSE Addis Ababa in Association with -20- Deta.l Des.gn of Bald Gaduia img^nT^ramageF^ect ICT Pvt Ltd and AECt LC October 2011Ministry of Water and Energy - Federal Democratic Repubbc of Ethiopia Section - I, Volume - VII Operation and Maintenance Mafoal-H- ln all types of the division boxes the head regulators and cross regulators are designed to be associated with broad crested weirs for discharge measurement purposes At field level zero-slope ditches are included to have effective head regulation activities at the furrow neads Summary of the various structures designed for the system is presented in Table 2.7 Table 2.8 : Summary of Type of Structures Designed S.No. Name of Structure MC-1 SC’S TC’S Total 1 Aqueduct 2 00 2 2 Head Regulator 1 52 0 27 3 Escape Head 1 00 1 4 Cross Regulator 1 26 0 27 5 Broad Crested Weir 26 0 27 6 Partial Flume Module 1 0 1 7 Tail Cluster 1 30 150 181 8 Road Bridge 1 0 0 1 9 Culvert 000 0 10 Dram Culvert 0 30 150 180 11 Canal Siphon 100 1 12 Supply Canal Fall (Type A and B) — I------------------- 202 488 0 690 1 13 Supply Canai Falls (M-1 and M-2 Types) Falls in Drainage Systems (TypeA and B) — |—■-------------- 0 0 1530 1530 T* ' 1 14 0 0 0 790 Total 212 640 1850 2702 2 3 Irrigation System Layout 2.3.1 Layout for Canal Networks and Tertiary Units (TUs) Detailed system layout design has been planned using the base topographic map of the command area.In the case of BAGID project the command area is located on the left bank of the Weyb River This command area is labeled as command area-l termed in short as BAGCOMA-I There is only one Main canal supplying this command area and the same is named as BAGMC-I The system lay out consists of BAGMC-1 30 Secondary Canals (SCsj to feed 30 blocks iBLKsi ana 150 Tertiary Units (TUs) supplied by 150 Tertiary Canals (TCs) With a rotai net area of 365 ha and 7 TUs BLK-1-10 is the largest Dlock in this command area The remaining blocks range from 340 ha (BlK-1-14) to 35 ha (BLK- 1-D Table2 8 WWOSH Addis Abaoa ir Association with -21- Detail Desion of Balp Gadula Imqation & Dramaoe P'Oiert •lTPu L'd anaABCEPLC n. *Ministry of Water and Energy ■ Federal Democratic Republic of Ethiopia Section -1. Volume - VII Operation Table 2.9: Layout of BAGCOMA-I Block No Supplying Canal Net Area Coverage (%) Block No Supplying Canal Net Area Coverage (ha) (ha) (%) ------------1 BAG BLK 1-1 BAG-SC-1-1 35 1 32 BAG - BLK-1 16 I BAG SC 1 16 195 7 33 BAG - 1BLK-1-2 0AG-SC-1-2 100 3 76 BAG BLK 1-17 BAG-SC-1-17 215 1 BAG ■ BLK-1-3 BAG-SC-1-3 295 11 09 BAG - BLK-1 18 BAG-SC 1 18 90 BAG BLK-1-4 BAG-SC 1-4 125 4 70 BAG BLK-1-19 BAG-SC-1-19 105 BAG BLK-1-5 BAG-SC-1-5 115 4 32 BAG - BLK-1-20 BAG-SC 1 20 100 BAG - BLK-1-6 BAG-SC 1-6 110 4 14 BAG - BLK 1-21 BAG-SC 1-21 165 BAG - BLK-1-7 BAG SC-1-7 150 564 BAG - BLK-1-22 BAG-SC 1-22 275 — BAG - BLK-1-8 BAG-SC-1-8 190 7 14 BAG ■ BLK-1-23 BAG-SC 1-23 135 BAG - BLK-1-9 BAG-SC-1-9 200 7 52 BAG ■ BLK-1-24 BAG-SC-1-24 165 BAG - BLK-1-10 BAG-SC-1-10 365 13 72 BAG BLK 1 25 BAG-SC 1-25 195 8 08 338 3 95 3 76 6 20 1034 5 08 620 7 33 I---------------------- — BAG-BLK-1-11 BAG-SC-1-11 170 6 39 BAG - BLK 1-26 BAG-SC-1-26 195 i BAG BLK-1-12 BAG-SC-1-12 215 8 08 BAG BLK-1 27 BAG-SC-1-27 290 BAG-BLK-1-13 BAG-SC-1-13 115 4 32 BAG - BLK-1-28 BAG-SC 1-28 200 7 33 10 90 7 52 BAG - BLK-1-14 BAG-SC 1-14 345 12 97 BAG - BLK-1 29 BAG-SC-1 29 100 3 76 BAG - BLK-1-15 BAG-SC-1-15 130 4 89 BAG-BLK-1-30 j BAG-SC-1-30 130 4 89 Total 5150 100.00 Source BAGID Irrigation System Layout Design The main canal planned to supply tne entire command area of the project is designed to run over the major ndge located at the center of the valley and bisects tne command area into the left ton the hill side; and right sides of this main canal In tne general east-west direction the valley in the command area has a length of 35 km The first 5 7 km located u/s of the Asendabo crossing is designated as the u/s reach of the command system The command area that lies between the Asendabo crossing and the Goro-Gimr main road crossing having a direct length of 11 50 km is identified as the middle course of the command system D/s of the Goro-Gimr mam road crossing including the left and nght side command areas having a direct 20 km is designated as the d/s reacn of the command system The width of the valley vanes from 1 km in the u/s reach of the command area enlarged to 2 5 Km at the middle of the command area and narrows down to 2 km in the further d/s reach of tne command area BLK-1-3 and BLK-15 in tne u/s reach of the command area are located in the left side of tne command system BLK-1-8 BLK-1-10 & BLK-1-14 as located in the middle course of the command system are also located in the left side of the major ndge in which the main canal is aligned Furthermore, BLK-1-18, BLK-1-21 BLK-1- 22 BLK-1-25 BLK-1-27 and BLk-1-28 all located in the left side are also located in tne further downstream reach of tne command system On tne other hand BLK-1-1 BLK-1-2 BLK-1-4 and BLK-1-6 are all in the u/s reaches located in the ngnt side of the command system Seven blocks (Blk-1-7 Blk-1-9 Blk-1-11 Blk-1-12. Blk-1-13 Blk-1-15 and Blk-1-16) are located on the right side middle course of the command system The balance that includes Blk-1-17 Blk-1-19 Blk-1-20 Blk-1-23. Blk-1-24 Blk-1-26 Blk-1 29 and Blk-1-30 are all located on the right side and in the downstream reacn of the command system WWDSE Addis Ababa in Association with *22- Detail Design of Bale Gadula Imgation & Drainage Protect <CT P\'t Lid and ABCF PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -I, Volume - VII Operation and Maintenance Manual The size of a TU ranges from 10 ha to 90 ha The optimum and manageable number of farmers to be incorporated in a tertiary unit (usually considered to be not to exceed 100) and the shape and orientation of topography of the command area are used as a basic criteria to characterize the size of TU’s It is assumed that a family can be provided with one ha irrigated land TUs more than 100 ha are considered to be difficult for management At the same time TUs less than 20 ha are also considered not advisable The total net imgable command area for the project is estimated at 5150 ha. In the command system of the project, SCs are designed to off take from MC-1. TCs from SCs and finally furrows to off take directly from TCs All of the 150 TCs are designed to off take directly from the respective SCs, no TC is arranged to off-take directly from MC-1 BAGMC-1 is a contour canal for very short reach (less than 2 km) around the headwork and runs across the contours for the remaining 29 km of its length BAGMC-1 is running at a slope of 0 01% crossing the command area at its center SCs are contours in some reaches and runs across the contours in some other reaches This arrangement is governed by the orientation of the contours of the command area Some SCs are designed to irrigate on both sides and those contour SCs are designed to command on one side only TCs are arranged to run cross the contours This arrangement is exclusively made for TCs to enable furrows/corrugations to run along the contour at some optimum furrow slope which is designed to oe 0 75% for furrows and 1 0% for corrugations as in the case of Bale- Gadula project 2.3.2 Furrow Layout Furrows are designed to be the last conveyance unit in the command system of BAGID Project Furrows are arranged to directly off-take from Tertiary canals Optimum furrow/corrugation slope is designed to be 0 75% for furrows and 1 0% for corrugations ana optimum furrow/corrugation length is computed to be 200 Capacity statements of TCs SCs including length of canals for the command system are presented in Annexure-VIII. The schematic presentation in Figure 2.3 illustrates the system layout design at tertian/ units including furrow field drainage Figure 2.2: Details of Irrigation System layout WWDSE Aadis Ababa in Association with -23- Detail Desiqn of Bale Gadula Irrigation & Drainage Project ICT P.t Ltd and ABC£ PLC October 20? ’Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I, Volume - VII 3. THE OPERATION & MAINTAINANCE MANAGEMENT STRUCTURE 3.1 Principles of the O and M Management Structure Organizational structure for tne management of operation and maintenance activities of public projects like the Bale-Gadula Irrigation and Drainage Project can be categorized in two forms (i) Segregated type of Organizational Structure and (li) Integrated type of Organizational Structure In Segregated type of organizational structure the various management functions are performed by different groups such as the imgation & agriculture department, the cooperative & social service department etc in this type of arrangement each group is capable of developing its own structure to satisfy individuals as it is perceived by each unit Line of communication is not clearly defined and objective of different orgamzations/groups may vary which in turn bnngs divergence of management activities at household /farm unit level In tne case of integrated structure all the management functions are performed by one centralized management group that is established for a particular project to provide services for beneficiary households/farm units The organization is controlled from top to bottom Such an arrangement can be autocratic in its function but line of communication duties and responsibilities are clearly defined An institutional study for the project has been conducted as part of the feasibility studies of the project and the report is presented in Volume-XAnnexure-XIV of the feasibility phase report The study has selected an integrated type of organizational arrangements for the operation and maintenance and overall project management activities The study has defined the organogram for the management unit, duties and responsibilities of the organizational structure and manpower requirements to function as a management unit. It also designs the staffing plans and salary structure considering their size location, the prevailing labour market and the availability of trained personnel in the locality 5.1.1 Project Management For the project control centers to oe established for the management of the irrigation schemes an organization structure staffing pans and salary structure is designed considering tneir size, location, the prevailing labour market and the availability of trained personnel in the locality Based on the information so obtained during the study visits and discussions with various bureaus of Oromia Regional State and in line with the terms of reference of the study the sub-consultant proposes the following • An organization structure • A staffing plan • Job evaluation job grading • A salary scale pan WWDSE Addis Ababa in Association with -24- Detail Design of Bale Gadula Imgation & Drainage Project ICT Pv' Ltd and ABCE PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation end Maintenance Manual 3.2 Duties andResponsibilities of the Irrigation Project Management Unit (PMU) An institutional study requires among other information, a clear definition ano scope of functions responsibilities and mandate of the institution under study The role and duties of the irrigation project, as conceiveo by the consultant, in its feasibility report (Volume-XAnnexure-XIV) is summarized as follows • Manage the irrigation schemes and drainage systems • Plan, organize direct and supervise the operation and maintenance of the irrigation schemes • Ensure that enough irngation water is supplied to all water users ano supervise its proper use • Review prevailing rate of water cnarges from time to time and propose changes if required • Collect and administer water charges and fees • Promote the establishment of water users association ana encourage their participation in water management and maintenance works • Assist water users associations to utilize irngation water properly and to contribute their share in the up-keep of the field canals drains and farm roads • Provide tecnmcal support to water users • Take all the necessary precautions to minimize creation of ideal conditions for vectors of water borne diseases in and around canals and drains • Take measures to compensate for the adverse impact of the project on the surrounding ecology and environment • Manage staff according to the Labour Law • Ensure proper use of personnel finance and property • Provide training to members of water users associations on matters relatea to irrigation water use canai drain and road maintenance ana up-keep in association witn relevant regional offices • Provide training in record keeping proper use of tools and implements in association with regional Agriculture & Rural Development and other relevant offices Accountability of the PMU Until a basin authonty is established (Genale-Dawa River Basin Authonty) to take r the supervision of the project management center the MOWR shall assume esponsibility of assisting and directing them s regard MOWR may consider establishing nign powered units to supervise MCs coming up from various river basins until their basin authorities are blisned One of the options for this proposal is to maintain the High SE Acftfa Aoaba in Association with -25- Dera.; ; rd ancABCEPLC Bale Dacula Irngation & Drainage Projet t Octotw 2011Ministry ol Water and Energy - Federal Democratic Republic of Ethiopia Section - I, Volume - VII Operation ana Maintenance Manual—-------- Executive Committee for the purpose of supervising PMCs until their respective basin authorities are established and effectively operational 3.4 Some Important Basic Facts of the Project The assumptions for the proposed organization structure of Bale Gadula Irrigation Project are • Bale Gadula Irrigation Project has an estimated net command area of 5,150 ha • It is understood that the diversion weir has one outlet gate, one on left bank of the nver Weyb • There will be 150 outlet gates from the diversion, main canal and secondary canals • Number of outlet gates to be assigned to an attendant depends on the size and location of off-takes Thus one attendant is assigned for the outlets at the we.r • Thus the required number of attendants per shift is 20 • It is assumed that irrigation would De earned out 24-hour a day Gate attendants will be deployed for two shifts a night and a day shift Hence the total number of attendants would 40 • Equipment & machineries requirement for civil works maintenance of the major infrastructure of the project are Heavy equipment • Motor Grader 150 HP 2 • Dump Truck 10MJ 4 * Backhoe Excavator -2- o Miscellaneous Transport • Flat Bed Truck • Tractor 2WD -1- -1- • Trailers 4 5 tons -1- ■ 4WD SW hard top -1- • 4WD Double Cabin Pickup -2- ■ 4WD Single Cabin Pickup -4- ■ Motor Cycle -4- • Bicycles 15 Procurement and acquisition of equipment ano maemnenes should completed in the early stage of the project implementation depending on progress of project development WWDSE Addis Ababa in Association with -26- ICT Pvt Ltd and ABCE PLC Detail Design of Bale Gadula Irrigation & Drainage Pro/ect October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -l^/olume - VII _______Operation arid Malnt&hbnco Mdhual • Maintenance of water supply conveyance and drainage canals consists of removal of deposited silt matenai to maintain initial design capacity • Field canals ana field drains maintenance water distribution activities to farmers after the after tertiary off-take gates and all manual activities in the process of irrigation and drainage network maintenance and upkeep are to be carried out by water users associations • Water users associations are assumed to be responsible for collecting water charges from individual members and hand over to the PMC A water gate is earmarked for one water user association in this case with varying number of members It may be possible for a tertiary canal to deliver water to more than one water user associations depending on the size of land holding of farmers which may not be the case in this project as Oromia decision limits ownership to half a hectare 3.5 Areas of Activities of WUA’s Areas of activities where Water Users Associations can usefully participate in water delivery and management are a) farm roads maintenance and up-keep d) field canals and field drams maintenance and upkeep c) irrigation water programming and distribution d) aepute project management within farms e) water charges and fees collection f) protection of water from pollution and unhygienic practices gj information ano feed-back trafficking h) facilitation of training awareness creation and coordination of efforts among members to enhance group efforts 3.6 Water Users Associations and DA vs Command. AREA Ratio One Water Users Association (WUA) is established for each Tertiary Unit greater than 20 ha in the command system and a water gate constituting heaa regulator and broad crested weir as discharge measurement structure is earmarked for one Water User Association in this case with varying number of members In the Bale-Gaaula command system each tertiary canal is designed to deliver water for each TU and/or WUA On the other hand each secondary canal is designed to deliver water for a farm block in the command system that constitutes different number of tertiary units The minimum area for TUs to establish the WUA is considered to be 20 ha and the maximum should be limited to 100 ha with the possibility of extending this upper limit to 150 ha TUs with command size less than 20 na snail be grouped together to establish one WUA The number of TUs and WUAs proposed for Bate Gadula Irngat.on ana Drainage Project is given in Table 3 1 WV\'DSE Addis Ababa m Association wi'h -27- Deta’I Design of Bale Gadula irrigation & Drainage Project *C '' Pvt Ltd ana ABCE PLC October 2011Ministry of Water and Energy - Federal Democratic Repuolic of Ethiopia, Section - I, Volume - Operation and MamtenanceM^i Table 3.1 : Number of TUs and WUAs Proposed Block No No of TUs < 20ha No of TUs >=20ha I----------- Total TUs “j— Proposed No of WUAs No of DAs Proposed Remarks BLK-1-1 1 1 2 1 1 DA Holding 35ha BLK-1-2 0 2 2 2 1 DA Holding 100ha BLK-1-3 2 8 10 9 2 DA Holding ranging from 125ha io 170ha BLK-1-4 0 3 3 3 1 DA Holding 125ha BLK-1-5 1 2 3 2 1 DA Holding 115ha BLK-1-6 0 3 3 3 1 DA Holding 110ha BLK-1-7 5 3 8 5 1 DA Holding 150ha BLK-1-8 0 7 7 7 1 DA Holding 190ha BLK-1-9 0 5 5 5 1 DA Holding 200ha BLK-1-10 1 6 7 6 2 DA Holding ranging from 170ha to 190ha | BLK-1-11 2 3 5 4 1 DA Holding 170ha BLK-1-12 0 6 6 6 1 DA Holding 215ha | BLK-1-13 2 2 2 1 DA Holding 115ha BLK-1-14 i 6 . 10 16 11 2 DA Holding ranging from 160hato185ha BLK-1-15 0 3 3 3 1 DA Holding 130Aa BLK-1-16 0 4 4 4 1 DA Holding 195ha DLK-1-17 0 6 6 6 1J DA Holding 215ha ( BLK-1-18 0 2 2 2 1 DA Holding 90ha 9LK-1-19 0 3 3 3 1 DA Holding 105ha BLK-1-20 0 3 3 3 1 DA Holding 100ha BLK-1-21 1 4 5 4 1 DA Holding 165ha BLK-1-22 0 4 4 4 2 DA Holding ranging from 130ha to 145ha BLK-1-23 1 3 4 3 1 DA Holding 135ha BLK-1-24 0 3 3 3 1 DA Holding 165ha BLK-1-25 1 5 6 5 1 DA Holding 195ha BLK-1-26 I 2 5 7 6 1 DA Holding 195ha BLK-1-27 3 8 11 9 2 DA Holding ranging from I35ha to 155ha BLK-1-28 0 4 4 4 1 DA Holding 200ha BLK-1-29 0 3 3 3 1 DA Holding 100ha BLK-1-30 0 3 3 3 1 DA Holding 130ha Sum 26 124 150 131 35 3.7 Functions of WLIA’s Areas of activities where Water Users Associations can usefully participate in water delivery and management are • Perform water allocation at farm unit level together with the DA on the basis of equity water distribution WWDSE, Addis Ababa in Association with 28- Detail Design of Bale Gadula Irrigation^ Dramaae Proiect IC r Pvt Ltd and ABCE PLC October 2011Ministry of Water and Energy - Section - -W Federal Democratic Republic of Ethiopia_____ —_________________ Operation arid MaintenSric^Manual • Over-all irrigation water programming and distribution at farm unit (TU) level • Commit project management activities within farm units • water charges and fees collection • field canals and field drains maintenance and upkeep • farm roads maintenance and up-keep • protection of water from pollution and unhygienic practices • Information and feed-back on water thefts • Facilitation of training, awareness creation and coordination of efforts among members to enhance group efforts. • Maintenance of water supply conveyance and drainage canals consists of removal of deposited silt material to maintain initial design capacity • Field canals and field drains maintenance, water distribution activities to farmers after tertiary off-take gates and all manual activities in the process of irrigation and drainage network maintenance and upkeep are to be carried out by water users associations 3.8 Proposed Organizational Structure for the PMU 3.8.1 Technical Advisory Committee The Proposed Organization Structure for the project has a Techmcal/Advisory Committee, two line sections. Water Management & Environment Protection and Technical Sections and one support service, Administration Service. Technical'Advisory Committee will be composed of: a Head, Woreda Administration Chair person b head Water Resources Development Desk D/Chair person c. Woreda Agncultural and Rural Development Desk d Head Woreda Cooperatives Organization Desk e Head, Land Use Admin & Environment Desk Member Member Member The PMC shall act as secretary for the committee The role of the committee is to advise the PMC achieve its goal by providing technical assistance and expertise in vanous fields. 3.8.2 Project Management Unit (PMU) Project Management Unit will work under GenaleDawa Basin Authority to be created Till such time it is not created the PMU will work under a Authonty/ High Power Committee under MOWR/ Oromiya State This will be situated near to the Command for efficiency and nearness to the farmers and will be decided in Infrastructure Studies WWDSE. Addis Acaba in Association with -29 Detail Design of Baie Gaduia imgation & Drainage Project iCT Pvt Ltd and ABCE PLC October 2O11Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 3 8.2 1 Major Functions Section -1, Volume - VII Operation and Maintenance [a/ Major Functions of PMU units in the organization structure can be outlined as follows, i) Manager: PMU The manager of the scheme will be accountable to the High Executive Committee temporarily, until the basin authority is established The manager will oe responsible for the overall planning, organizing, coordinating and controlling of the activities of the PMC ii) Administrator Administrative Section will be responsible for a) personnel administration b) book keeping and accounting c) Store administration d) general service provision e) records management iii) Water Management & Environment Protection Section Water Management & Environment Protection Section will be responsible for a) water supply and control bj environment and health protection c) permit and fee collection and management d) data collection ana management on water supply and use iv) Technical Section Civil and Mechanical Tecnmcal Section Civil and Mechanical will be responsible for a) Construction Supervision of Infrastructure, Buildings, Roads, Diversion Weir, Main Secondary and Tertiary canals, Network structures b) Flood protection dykes if any c) Drainage systems d) Maintenance of equipment machineries, vehicles etc All repair and maintenance of equipment, machineries, vehicles, motor cycles etc would be handled by a central workshop The number of technicians suggested in this report, to be assigned to the central workshop is omy for the initial phase Additional technicians may have to be recruited from time to time as the need arises 3 8 2 2 Functions of Development Agents The Proposed integrated type of Organizational Structure for Bale-Gadula is presented in Figure 3.1 as taken from the institutional studies (Volume-X Annexure-XIV) with minor modifications to suite the cases in this 0 & M manual WWDSE Addis Ababa in Association with 30- Detail Design of Bale Gadula Irngation & Dramaoe Prr9erf ICT Pvr Ltd and ABCE PLC Oc ^ ?Ministry of Water and Energy - Federal Democratic Republic of Ethiopia.—-------------- Section -1, Volume - VII Operation and WaWelttMBMihbdttllk The PMU at the project head level have been designed to constitute three technical sections and one support section as indicated in Figure3.1 The water management and environment protection sections shall handle all water management and operation activities including the planning, regulation and routine water distribution activities at tertiary unit level. This responsibility of the PMU shall be properly linked to the WUAs located at the respective tertiary units (TUs) level in the system. The Development Agents (DAs) as part of the PMU staff shall play the liaison role between the PMU and the WUAs and/or the farm units (TUs) The DAs together with the WUAs are subjected to work with the planning, and regulation activities of water distribution systems at tertiary unit level This include) computation of the daily water balance of the root zone (soil water-plant relationships at the canopy of the crop), estimation of the demana at the tertiary unit head, and regulation of the both the head regulators and cross regulators at the respective division boxes. By the end of every working day, the DA together with the WUA shall estimate the water balance in the root zone and the demand at the Tertiary head and this shall be reported to the PMU headwork for the next day planning and regulation works. The input supply research and technology transfer section is responsible for availing agncultural inputs, run research activities and design appropnate mechanisms to transfer the technology assist the WUAs and cooperatives in assessing markets and in organizing the market outlets This section can use the farmers plot to run researcn activities and also can have its own demonstration plot to run specific research activities like testing conditions and/or varieties. The section shall run meteorological equipments like rain gauge and collect the data This delegation can be vested from NMSA (National Meteorological Service Agency) This service shall also plan, organize, and implement training and knowledge transfer activities both to the technical staff of the PMU. the DA and the farmers/WUAs The maintenance and technical service section, as the name implies, is responsible for maintenance of the irrigation system, equipmentand other pertinent components. Replacement of equipment, gates etc whenever it deems necessary is also responsibilities of this section. To perform such activities the section shall have well organized workshop The job description of different officers I staff / workers is given in Appendix - I. 3.8.3 Proposed Manpower Requirement Though the three project management centers are going to have similar organization structures they will slightly vary in their manpower needs particularly at their miadle and lower echelons Yadot& B/Gadula Project Management Centers have similar staffing plan except for their Gate keepers The proposed staffing plan for YADOT project management Unit is as follows Table 3.2: Project Manager’s Office S.No Job Title No. of Positions I 1 Projeci Manager 1 I Grade 15 ------------------------------------------------------------------------- —_•_________________ WWDSE Addis Ababa in Associauon with -31- Detail Design nf Bair Gadula irrigation & Drainage Project •CT Pvt Ltd and ABCE PL C October 2011Ministry of Water and Energy - Section - 1, volume - VII Federal Democratic Republic of Ethiopia Operation and Maintenance Manual 2 | Secretary 1 8 Total 2 Table 3.3: Administration Service S.No Job Title No. of Positions Grade 3 Head Administration Service 1 13 4 Secretary Typist 1 6 5 Personnel Officer 1 10 6 Clerk, Personnel & General Service 1 4 7 Clerk Records and Documentation 1 4 8 Training Officer 1 10 9 Head Finance Service 1 13 10 Accountant 2 9 11 Head, Stores 1 8 12 Purchaser 1 7 13 Store Keeper 1 5 14 Cashier 1 7 15 Driver II 1 7 16 Driver I 9 5 17 Assistant Driver 1 3 18 Heaa Guard 1 3 19 Guard 6 2 20 Cleaners 4 1 Total 35 Table 3.4: Water Management & Environment Protection Section S.No Job Title No. of Positions Grade 21 Head, Water Management Unit (Imgation Engineer) 1 I' 14 22 Head Environment Protection & Sanitation Unit 1 12 23 Water Management Expert 1 10 24 Environment Officer 1 10 25 Gauge Readers and Gate operators Diversion Weir 6 3 26 Gauge Readers ana Gate operators at other Regulators 8, 3 27 28 Statistician 1 9 Data collectors 2 4 29 Wireless operators 4 4 30 Messengers 6 2 Total 38 No Table 3.5: Technical Services CIVIL JOB TITLE| No of Positions 30 Heaa TechmcaHJnit |1 31 Head Civil Engineer I Diversion weir ” Grade 14 13 WWDSE Addis Ababa in Association with -32- Detail Design of Bate Gadula Irrigation & Drainage Project ICT Pvt Ltd and ABCE PLC October 2011Ministry of Water and Energy • Section - /. Volume - VII Federal Democratic Republic of Ethiopia ______________ Operation ano Matnten&n&NartlMttB. I 31 Foreman Civil Eng Diversion weir 2 10 Head Civil engineer Canal 1 32 System 1 ’’ 33 Foreman Civil Eng Canal system 4 10 34 Supervisors 6 8 33 CAD Operator 1 5 I ■ Totai 16 Table 3.6: Technical Services Mechanical S.No JOB TITLE No of Positions Grade 35 Head Mechanical Unit 1 13 36 Machine Operator 2 7 37 Assistant Machine operator 2 5 38 Head Workshop 1 12 39 Maintenance Foreman 1 10 40 Senior Mechanic 1 9 41 Mechanic 1 8 42 Electrician 1 6 ' 43 Welder 1 6 44 Assistant Mecnamc 4 5 Total 16 The staffing plan proposed for the Project Management Center is summanzed in the following table Table 3.7:Summary of Staffing Plan Section Number of Staff Project Manager’s Office 2 Administration Section 35 Water Management Section Technical Section civil Technical; Section mecnanical Total 3 8 3 1 Qualification Requirement 38 16 16 107 The qualification requirement for the proposed man power is given in Table 3.8 Table 3.8: Proposed Qualification for Requirements S.No Job Title Qualification Requireo Experience Training 1 Cleaner 8* grade 2 Guard tTGrade /1 month/ 3 Head Guard 8,r' Grade 2 years 4 Gate Keeoer 10™ Grade — 5 Data collector 10* Grade 2 years 6 Clerk 11™ Grade 7 8 9 Store Keeper 12™ Grade Complete 1 year Secretary Typist 10*2 in Secretarial Science 2 years ------------------ H Purcnaser 12™ grade complete 10 Cashier 12* grade complete Security deposit 11 Secretary College Diploma in Secretarial Science 2 years 12 Head Stores College Diploma in Supply 2 years WWDSE Addis Aoaoa in Association with -33- Derail Design of Bale Gadula Irrigation & Drainage Project iCT^vf Ltd and ABCE PLC October 2011Ministry of Water and Energy - Section -1, Volume - VII Federal Democratic Republic of Ethiopia_____________________________ Operation andMaintenanc^anuai^^ — Management 13 Assistant Diver 10" Grade 1 year Driving License 14 Driver I 15 Driver II 16 Assistant Mechanic 10'h Grade 10" Grade Certificate in Auto mechanic 2 years 2 years Driving License Driving License 2 years 17 Welder Certificate in Welding 18 Macmne Operator 10" Grade 19 Electrician College Diploma in auto electricity 20 Mechanic College Diploma in auto mechanic 21 Senior Mechanic College Diploma in auto mechanic 22 Accountant College Diploma Accounting 23 Statistician College Diploma in Statistics 24 Training Officer College Diploma in Management 25 Environment College Diploma in environment Officer science 26 27 Personnel Officer College Diploma in Management 2 years 6 years License 2 years I 2 years 1 4 years 4 years 1 6 years 28 Maintenance Forman 6 years _______1 1 29 Civil Work Forman College Diploma in Aeromechanics College Diploma in Civil Engmeenng 6 Years 30 Supervisors Class 10" pass 31 CAD operators Diploma in CAD Operation 32 Foreman Civil Diploma in Civil engineering 33 Head. Workshop BSc in Mechanical Engmeenng 1 2 years 1 2 years 4 years ■ 34 Head Mecnanical Unit 35 Head Civil Works Unit 36 Head Environment Protection unit BSc in Mecnanical Engineering BSc in Civil engineering College Diploma in Environment Science 4 years ■1 1 2 years 1 6 years .- 37 Head Water BSr in Civil Engineenng/lrrigation Management Unit Engmeenng J 6 years I L 38 Head. Finance Service BA in Accounting 6 years 39 Head. Administration BA in Management Service Il 6 years 40 Civil Engineer BSc in Civil engmeenng 2 years - I 41 Head Tecnmcal Section civil 1r BSc in Civil Engineering 6 years 42 Head. Water BSc in Hydrology or Irrigation manaaement Unit Engmeenng 1 6 years 1 43 PMC Manager BSc in Civil Engineering 6 years i ■ WWDSE. Addis Ababa in Association with ICT Pvt Ltd and ABCE &LC -34- Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Mmistiy of Wale/ and Eneigy rat Democratic Republic of Ethiopia Section - / Volume - VIII Operation and Maintenance Manual Figure 3 1:Bale Gadula Irrigation Project - PMU WWDSE Addis Ababa in Association with Id Pd Lid and ABCE PLC -35 Detail Design of Bale Gadula Irrigation & Drainage Project October, 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia ■ ~ ---------------------------------------------------- --------------------------- 4. IRRIGATION SYSTEM OPERATION SERVICES 4.1 Soil-Water-Plant Relationships 4.1.1 Generals The knowledge of soil-water-plant relationship plays important role is developing efficient water management practices at farm level There are a number of factors that affect the soil-water-plant relationship we need to consider Providing basic principles of the soil-water-plant relationship in this operation and maintenance manual seems to be pertinent to help the PMU develop the water balance of the system during operation services Such information's* are also pertinent for planning of water distributions and regulation of system equipments/structures. 4.1.2 The Soil Soil is a complex system made up of solid, liquid and gaseous matenals. The mineral portion consists of particles of various sizes, shapes and chemical composition These particles are classified according to the size of the grains, as sand silt, and clay which essentially determine the texture of the soil. The organic fraction consists of both plant and animal matter some of which are alive, while otners are in different stages of decomposition The accumulation of partly decomposed organic matter is the humus fraction of the soil, and usually constitutes a very small fraction of the solid phase of the soil in and regions. The liquid portion of a soil consists of the water dissolved minerals, and soluble organic matter which fill part, or most, uf the spaces between the solid replemsnea oy rain or irrigation water for the successful production of crops. Thus tne soil serves as a reservoir for moisture This moisture reservoir and knowledge of its capacity are principal factors governing the frequency and amount of irrigation water to be applied to the land These vanables are important to simulate the water balance within the crop canopy in the system. The gaseous or vapor portion of the soil occupies that part of the spaces between tne soils particles not filled with water This is an important phase of the soil system as most plants require some aeration of the root system, with the exception of aquatic plants such as rice ano taro irrigation practice is important in maintaining a reasonable balance between the soil moisture and air 4.1.3 Soil Texture The texture of a soil is determined by the size and distribution of the soil particles i.e. the proportions of course, medium, and fine particles which are termed sand, silt and clay respectively Vanous combinations of these fractions are used to classify soil according to its texture The textural class of a soil can be accurately determined in the laboratory by mechanical analyses Sand silt and clay are size groupings of soil particles Sands range from 2 to 0 05 millimeters silt from 0 05 to 0 002 mm and clays less than C 002mm in d.ameter These three particle sizes mixed together in various proportions constitute the soil class Section - /, Volume - VII Operation and Mamtenapoe^nualt WVVDSf Addis Ababa in Association with -36- Detail Design of Bale Gaduia Irrigation & Dramaoe Protect ICT Pvt Ltd and ABCE PLC October 2011Ministry of Water and Energy - Section -1, Volume - VII Federal Democratic Republic of Ethiopia__________________________ — Operation and Maintenance Manual 4.1.4 Soil Structure The structure of a soil refers to the arrangement of the soil particles and the adhesion of smaller particles to form large ones or aggregates On the surface, soil structure is associated with the tilth of the soil The permeability of a soil for water air and the penetration of roots is influenced primarily by the soil structure Soils without definite structure may be single grain types, sands, or massive types such as heavy clay Crumbly or granular structures are desirable for good imgation management and crop growth. 4.1.5 Storage of Soil Moisture Soil is a porous material composed of particles of many different sizes touching each other, but leaving spaces in between The space not occupied by the particles is known as “pore space" and for most soils constitutes 40 to 60 percent of its volume. Water is stored in the pore space This stored water or soil moisture is used by the plant and in the absence and/or insufficient rainfall conditions it must be replenished by irngation The following discussion covers the water-soil- plant relationships 4.1.6 Saturation During and immediately following surface imgation, the soil below the water surface is nearly saturated All the pore space or small openings between the soil particles are almost completely filled with water There is little air present in the saturated soil Since plants with the exception of rice, need air as well as water, some or the water from tne larger pores must move out in a reasonable length of time to prevent damage to the crop If the soil is well drained, part of the water will move downward Dy gravity ana to a limited extent laterally Dy capillarity. The water moving downward by the forces of gravity is called gravitational water or free water 4.1.7 Field Capacity The amount of water retained after drainage of saturated soil is called field capacity At field capacity each soil particle is completely surrounded with a relatively thick film of water However, most of the water is located in the form of wedges between the soil particles It is from these wedges that plants obtain most of their water The moisture held in the soil against gravity may be described in terms of moisture tension Tension values may be expressed in equivalent atmospheres or height of water column in centimeters/meters. In converting soil moisture tensions to equivalent atmospheres 1 atmosphere is approximately equal to a suction or a negative pressure of 1000cm height of water column. At field capacity a loam or clay soil retains moisture under a tension of about 1/3 atmosphere, or a water column heignt of 300cm, whereas sands may be as low as 0 1 atmospheres or a water column height of 100cm The volume of soil wetted to field capacity by irrigation will depend upon the dryness of tne soil, its texture, structure and the amount of water aDplied The moistened portion of a drained soil of uniform texture and structure reaches its WWDSE Addis Ababa in Association wth -37- Detail Design of Bale Gadula imgation & Drainage Project ICT Pvt >io ano ABCE ?LC October. 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - /, Volume - VII Operation and Maintenance.Manual^ fieid capacity two or three days after a rain or irrigation. This time period is increased if there are layers of soil which hinder the downward movement of water or with a very fine textured soil such as clay The field capacity of a soil depends upon the soil texture or size of the soil particles The surface area of the soil becomes larger and the number of points of contact between the soil particles is greatly increased as the size of the particles becomes smaller Therefore, a fine-textured soil will retain more water than the coarse textured soils. Sometimes soil moisture tension is expressed in PF value which is the logarithm (log 10) of the height of water column measured in centimeters Field capacity is in the range of PF=2to2.4 The very large surface area, or internal surface of soil, can be illustrated as follows 1 m3 of a silt loam has an internal surface area of 70000m2. Therefore a maize plant rooting 120cm deep has an internal soil area of 7 Oha from which moisture ana plant nutrients may be obtained At fiela capacity a cubic meter of a typically sandy soil will nold about 135 liters of water a loam soil about 270liters and a clay about 400liters. The addition of organic matter such as manures, straw or plant residue, will only slightly increase the filed capacity and usually only in the surface soil (this does not apply to nutrient value of these matenals or their influence on structure and permeability of the soil) 4.1.8 Permanent Wilting Point Removal of water from the soil by plant roots and direct evaporation causes the water film surrounding the soil particles to become thinner and thinner and most of the water in the wedges between the soil particles to disappear Finally, a condition is reached wnere the water is held so tigntly by the soil particles that the roots cannot remove it at a sufficiently rapid rate to prevent the leaves from wilting When this condition is reached the soil is at the permanent wilting point (PWP) The soil moisture tension has now reached about 14 to 15 atmospheres 4 or equal to a suction or negative pressure of a water column 1.5 x 10 cm high (p F = 4 2) At this level of soil moisture the removal of only a small amount of water about half to one percent decrease in soil moisture content, will greatly increase the negative pressure, to 30 or more atmospheres, with the ultimate death of most plants Wilting or drooping of tneir leaves is the most common symptom that the PWP has been reached Some plants will not wilt, but show other signs such as decrease plant or fruit growth or a change in appearance, such as leaf color Because it is difficult to obtain precise results from soil sampling and to determine exactly when a plant is wilted the term PWP is defined as a narrow range of soil moisture within whicn wilting takes place (tnis is often referred to in literature and in practice as the wilting point of a soil). The PWP covers a range of about 1 percent of soil moisture content in fine-texture soils and about 7? percent in sandy types The PWP is influenced by texture in tne same general way as the field WWDSE Addis Ababa in Association with -38- Detail Design of Bale Gadula Irrigation & Drainage Pro ect ICT Pvt Ltd and ABCE PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia capacity i e the fine-textured soils have a higher PWP moisture content than soils of coarse texture The wilting or drooping of leaves in mid-afternoon, or when the temperature is higher is a sign that soil moisture has been reduced close to the PWP If this wilted condition is still noticeable the following morning, for most soils, this means that the PWP has been reached in that part of the soil which contains the major portion of the root system Under these conditions the normal activities of the plant are limited 4.1.9 A vailable Water/Moisture (A W) This is the moisture above the PWP Considerable soil moisture is present below the PWP but is held so tightly by the soil particles that plant roots cannot absorb it rapidly enough to prevent wilting The water in the soil above the PWP throughout the entire range of moisture content up to field capacity (FC) can be used by plants and is considered the available moisture. The ratio of field capacity to the PWP is not constant. Research activities elsewhere in the globe indicate this ratio vanes from slightly above one to more than 4 Similar expenence has indicated that for many soils about half of the total water at field capacity is available for plant use thus giving a ratio of approximately 2 Therefore if either the field capacity or the PWP is known the other one can be roughly estimated for field work. The amount of available water varies with the soil texture For coarse textured soils sucn as sandy soils the gravitational or surplus water is rapidly removed by drainage The field capacity and the PWP are both low Consequently the amount of available moisture is small With soils of fine texture, such as clay or clay loam, the gravitational water is removed slowly by drainage and the field capacity and the permanent wilting are high These soils usually contain a large amount of available moisture Field capacity and tne PWP for all practical purposes are constant for any given soil. It is a common belief that adding organic matter to the soil improves its water nolding capacity However additions in amounts usually applied in the field will not change the water relations of the soil enough to be of practical importance It appears that the moisture characteristics on the soil are influenced by the manure treatment, particularly for the lighter textured soils. However this does not necessarily cause increased moisture availability to plants. The amount of water necessary to penetrate to a depth of 30 cm when the soil is ary (i.e when all available water has been exhausted) will vary with the soil type The approximate amount or aepth of available water for different soil textures is given in Table 4.1 During the detail design work the soils in the command area were sampled and laDoratory analysis work has been conducted to determine availaoie water holding capacity of major soils in the command area The laboratory analysis resultsare organized ana tabulated and this hydraulic feature of the soils in tne command area is presented in Table 2.6 for ootn future use WWDSE Addis Adana in Association with -39- Detail Design of Bale Gadula Irrigation i Drainage Project ICT Pvt Ltd ano A BCE PL C October 2011Ministry ot Water and Energy - Federal Democratic Republic of Ethiopia Section -1. Volume - VII Operation and Maintenance Manual and reference purposes The AW of the soils in the command area can be compared with the values given in Table 4.1 and texture of the soils in the command area can be approximated The values of AW for each particular soil type should represent the depth of water needed to bring a dry soil to moisture content near field capacity Table4.1: Available Water Holding Capacity of Soils of Different Texture Soil Texture AW (mm of water per m depth of soil) — Sands Coarse Sand and gravel 20- 60 40- 90 Loamy Sands 60-120 Sandy Loams 110-150 Fine Sandy loams 140-180 Loams and Silt Loams 170-230 Clay Loams and Silty Clay Loams 140-210 Silty Clay and Clays 130-180 The available -water (AW) per meter depth of soil is computed employing rhe formula presented in section 2 17 3 of this report. This laboratory result is presented here in this O and M manual assuming the direct use of the data in the aosence of laboratory analysis works at the project PMU. dunng the operation phase of the project The soil texture will often change throughout the depth of the rooting zone with a corresponding variation in the amount of available water figures in Tables 2.6 above illustrate considerable vanations in field capacity the permanent wilting point and tne available water aiong the depth of the Bale-Gadula command area soil horizon 4.2 Soil-Water Availability to Plants The concept of soil water availability to plants has been a controversial issue for quite some time In a general sense, the soil water which is bounded Dy the upper limit, FC and lower limit, PWP is considered available to plants, Recent research findings show that the actual availability may be the entire range or a part of it, depending on the properties of the plant (eg. rooting density depth, and rate of extension;, properties of the soil (storage, conductivity metric potential) and also to a very considerable extent on prevailing microclimatic conditions (wmch dictate the transpiration rate; The PWP which is defined as the soil-moisture content at which plants cannot recover overnight from excessive drying during the day was initially determined at the greennouse experiments to correspond to a range of 102m (10bars) to 204m (20bars) The 153m (15bars) is accepted as a median value Recognizing the importance of the plant in defining the lower limit of available water and realizing that crops in the field situations do not respond the same way as individual pots in a greenhouse experiments WWDSE Aadis Ababa m Association with -40- ICTPvt Ltd and ABCE PLC Detail Design of Bale Gadula Imgetion & Drainage Project October 201'Ministry of Water and Energy - Section - /, - f V//, Federal Democratic Republic of Ethiopia___________________________ Operation and Maintenan9Wanua!**r another term has been chosen to improve on the PWP concept especially dunng operation phase of the project This term is crop extractable water (CEW) which is defined as the soil-moisture content which exists when plants in a field condition cannot recover over night from excessive drying dunng the aay This term emphasizes that the plant vanety is of vital importance in describing the lower limit of available moisture as well as the soil texture and structure in the field. The impact of the plant type on the CEW is characterized using a term depletion ability of each crop to extract water available between the upper limit, the FC and the lower limit, the CEW and/or the PWP This fraction designated as P, is the fraction of available soil water and it is specific to each crop/plant type For normal irrigation however the time between irrigations is extended to utilize about half or more of the available soil water Research results elsewhere in the globe indicate that for similar soil tension water availability to plants is more in coarser soils than in fine textured soils For loam or coarser textured soils, almost 50 percent of the available soil water is used by the time the soil reaches 1 atmosphere of tension while less than 50 percent is used for the finer texture soils The allowable root zone water depletion between irrigation for near maximum yield (no stress conditions) for different crop is presented in Appendix* II 4.3 Measuring Soil Moisture 4.3.1 Data Collection/Sampling Procedures The collection of soil samples from various depths and locations in the field is the simplest and most widely used and probably the best method for measunng soil moisture The soil sample should be placed in an airtight container, such as aluminum or metal can, or a glass jar and sealed immediately to prevent the loss of moisture in the route to the laboratory The vapor condensing on the inside of the container should be weighed and included in the moisture determination since it was in the soil when the sample was taken. The moist samples are weighed, dried to constant weight in an oven at 105-110°° and reweighed The difference in weight of the soil is to give the percent of moisture on a dry weight basis When this method is used, samples are usually taken at several locations in the field and compiled to indicate the average soil moisture The samples can be obtained by use of a soil tube wmch gives soil cores of approximately equal volume or by one of the many types of augers which permit sampling at different depths A shovel or spade can also be used if proper precautions are taken to ensure a representative sample This method is laborious and time-consuming unless only the surface soil is sampled If the samples are composited each of tne sub-samples making up the composite should be approximately tne same size WWDSE Acdis Ababa in Association with -41- Detail Design of Bale Gadula Imgation & Drainage Protect ICT Pvt .to anaABCEPLC Oc £er 2Q„Ministry ot Water ana Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII ________________ Operation and Maintenance Manual 4.3.2 Instruments for Measuring Soil Moisture Various devices exist to measure soil moisture without the drudgery of soil sampling In general, these instruments have the advantage of immediate readings but they also have serious disadvantages Due to easy applications only one type the tensiometer is introduced here in this operation and maintenance manual. Tensiometers:Tensiometers are widely used for measuring soil water tension in the field and laboratory A tensiometer consists of a porous ceramic cup filled with water and connected through a water-filled tube to a reliable vacuum gauge Water moves into and out of the ceramic cup in relation to the soil water tension Tensiometers are used as sensors to maintain a desired soil water range. The major criticism of the tensiometer is that it functions reliably only in the wet soil range at tensions of about 0 8 atmospheres or higher This is not as senous as it may seem, because about 75 percent or more of the available water in coarse textured soils and about 25-50 percent in fine textures soils fall in this range Tensiometers are commonly used by trained technicians and irrigation scientists Out are not routinely jsed by farm managers. Where they are used as an irrigation scheduling tool, they are usually placed in pairs and at several sites within a given field Soil variation requires two to four sites per 65 ha to obtain representative measurements. At each site a tensiometer is located in the zone of greatest root density (30-50 cm) and a second at twice this depth The first is to schedule irrigations, the second is to detect deep penetration to show when irrigation should be terminated Table 4.2 gives some timing guidelines for interpretation of tensiometer readings. Table 4.2 : Interpretation of Tensiometer Readings Dial Reading in Atmosphere interpretation Nearly Saturated 0.00 Near saturated soils often occurs for a day or two 0 10 following irngation Danger of water logged soils, a high water table, poor soil aeration, or the tensiometer may have broken tension, if readings persist. Field Capacity 0 11 Field capacity Irrigation discontinued in this range to 0 20 0 30 prevent waste by deep percolation and leaching of nutrients beiow tne root zone Sandy soils will be at field capacity in the lower range with clay soils at field capacity in the upper range Irrigation Range 0 40 Usual range for starting irrigation. Soil aeration is 0 50 0 60 I assured in this range In general, irngations start at readings of 30 - 40 in sandy textured soils (loamy sands and sandy loams). Irngation usually start from 40 - 50 in loamy soils ivery fine sandy, loam, and silt loams) On clay soils (silty clay loams silty clays etc) irrigations usually start from 50 - 60 Starting irrigations in this range ensures maintaining available soil moisture at all times WVVDSE Addis Ababa in Association with ICT P^t Ltd ana ABCE PLC -42- Def ail Design of Bale Gaduia Irrigation & Drainage Protect October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I. Volume - VII Operation and Maintenance Manual 7 0 70 0.80 This is the stress range However, crop not necessarily damaged or yield reduced Some Soil moisture is readily available to the plant but is getting dangerously low for maximum production Top range of accuracy of tensiometer readings above this are possible but the tensiometer will break at tensions between 0 8 and 0 85 atmospheres Source FAO irrigation and Drainage Paper 1 REV 1 (Irrigation Practice & Water Management) 4.4 Principles of Farm Operation Operation of an irrigation scheme is as important as its design. Design and operation are closely linked, a poor design can lead to poor operation (or certainly difficulties) a good design enables efficient operation. However experiences of the past do tell that more attention has been paid to design than to operation of irrigation systems The fundamental causes of poor operation are - 1 Lack of technical skills in planning, implementing and monitoring the system 2 Poor man-management and inter-personal communication 3 Technical deficiencies in the physical system 4 inadequate levels of finance for 0 & M 5 Lack of political will ana motivation to effect cnange and improvements 6 inadequate/poor Operation of an irrigation scneme though technically quite straightforward, is one of tne most compiex management exercises in existence This is due to the interaction of tne social ooliticai economic and technical factors involved When considering system operation, and ways to improve it, it is necessary to divide tne problem into the following broad categories 1 Areas which are under tne manager s control and can be altered to suit new or revised management plants This is usually in the technical areas such as scheduling division of water, etc 2 Areas whicn influence tne ooeration of the scheme yet are totally out of the managers control. Government policy on crops, tax levels, funding levels etc 3 Areas wnich influence the operation of the scheme are out of the manager s direct control, but over which he can exert pressure and influence to effect his desired outcome Farmers cropping pattern, misuse and theft of water are typical examples In managing ano operating an irrigation system the manager must oe aDie to identify tne factors wmch fit into anyone of these three categories It is important that the operation personnel iDAs PMU managers and Operation managers) snail be ir a position to identify the various factors that will affect their farm system ooeration cract ?es Moreover categorizing these factors as indicated in tne above mree categories and taking their impact/effect on the operation VWVDSE Addis Adana m Association with -43- Detail Design of Bale Gadula irrigation & Drainage Proje. t <CTD.' Lrd ana ABDE ' October 2<~> 1Ministry of Water and Energy - Federai Democratic Republic of Ethiopia Section -1. Volume - VII Operation and Maintenance Manual practices while doing the planning of project operation is highly important and imperative The next important step that the managing personnel shall consider is adopt logical and attainable management strategies with which desired objectives can oe attained For such type of management practices having a good grasp of the technical aspects of system operation is essential 4.5 Basic Objectives of Farm Operation The principal objectives of any farm system operation requires that water is provided • At the correct time • In adequate quantity (disenarge and duration; • Reliably • With equity in distribution • With security (maintainability) of supply Satisfying these objectives involves the following tnree main activities.- • Planning for Operation • implementation of the Dian tactual water distribution) • Monitoring of the operation 4.6 Planning for Operation Objective is to match water supply witn demand as closely as possible Planning can De complex or simple targe scale oi small scale, and needs to involve the farmers Although planning is essential for efficient use of available supplies, it is often not done well, or at all Preparation of an irrigation or crop pian involves • Estimating future water supply wmeh involves collection of time series data for the supply and adopt proper frequency analysis works to estimate aepencaDie flows of the supDiy side • Estimating water demand of expected cropping pattern that involves fixing cropping pattern, identifying and quantifying cultivable areas, and identification of priority of allocations and irrigation efficiencies at various levels • Matcning supply and demand tnat involves establishing some criteria for supplying based on the availability and adequacy of the supply These criteria could specific to the respective irrigation season or simply could De a general policy adooted for the project including the design phaseMinistry of Water and Energy - Federal Democratic Republic of Ethiopia 4.7 Estimating Future Water Supply Section - /. Volume - VII Operation ano Maintenance Manual Can be straight forward or complicated depends on situation Limit may be set by physical constraints such as canal size (if d/s demand is extended beyond the design value) due to unprecedented hydrologic variability dependable flows may not be met during that particular farm operation period Dealing in such conditions it needs analyzing river and rainfall data For planning purposes frequency analysis techniques with probabilities of exceedance (i.e. use rainfall probability of 75 or 80 percent) can be employed Such analysis work needs data in which quantity and reliability (accuracy) of data would become important issue. 4.8 Estimating Water Demand Water demand determined by the cropping pattern and irrigation efficiencies at farm and project level A number of scenarios can be analyzed and most commonly encountered scenanos include 1) Cropping pattern fixed by project little or no notice taken of farmers’ preferences 21 Cropping pattern determined oy discussion and agreement between marace^ent a~c *'arme s r 3) Cropping pattern determined by farmers alone Case ii) is usually found on an integrated management's scheme (state farm or settlement schemes Hke ours) For case (ii) approval and rejection forms may be useful Farmers suomit cropping pattern for approval project management unit then approves or amends it oasea on the discussions that could be made with tne farmers Tne DAs are collecting the cropping pattern of the farmers aggregated by ternary unit. For case (lii) DAs and/or the PMU shall collect information on historical cropping patterns in order to analyses and determine the likely crop water requirements In all case demand may be limited by restricting growing of certain crops to specified areas (i e rice on clay soils not sandy soils), or by specifying an upper limit on permissible areas of particular crops For instance in the case of Bale- Gadula irngation project sugar cane should not be more than 50% of the project cropping pattern This restriction is made during the design phase which is made based on the dependable flow (80% dependable flow) of Bale-Gadula project. Such restrictions can be employed to limit the demand side so that mulching the supply and demand side can be possible Determination of the cop water requirements once the cropping pattern is fixed is fairly straightforward though additional data is required (soil types and characteristics climatic data crop characteristics) Detail computational procedures for evaluating crop warer equirements can be referred to FAO r Irrigation and Drainage Paper No 56-Crop .'Vater Requirements WWDSE Addis Anaba in Association with -45- Detail Design of dale Gadula Irrigation & Drainage Project r ,r " ~'d and ABCE October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - /, Volume - VII Operation and Maintenance Manual Efficiencies of the water distribution system at various ievels are required This data is often not available for the particular project and generalized empirical data is commonly used During the design pnase three levels of system efficiencies are identified (i) application efficiency this characterizes system losses at an application level (starting from the point the water is diverted to the furrow head) This value is fixed to be 70% as in the case of Bale-Gadula irrigation project: (ii) distribution efficiency: losses in the secondary and tertiary canal levels are characterized in this part of the project efficiency Assuming 85% efficiency for lined secondary canals and 80% efficiency for unlined tertiary canals distribution efficiency in Bale-Gadula Project is taken as 68%. and (ii) Conveyance Efficiency losses in tne main canal are characterized in this part of the project efficiency Since the main canals in the Bale-Gadula project are all masonry lined, conveyance efficiency of 90% is adopted Finally the aggregate of these three efficiencies forms project efficiency which is fixed to be 60% for the design phase These project efficiencies need to be verified during project operation phase It is therefore, recommended that collection of this key data is undertaken by the project as part of a standard data collection procedure and new set of project efficiencies specific to the project under consideration shall be established The various measurement structures designed for the system shall be used to collect these set of information/data for the system 4.9 Matching Supply and Demand This is the most difficult and interesting aspect of scneme operation; to decide on water distribution practices or other measures to provide the closest possiDle match of supply and demand In the attempt of matching the supply and demand of the system three main cases can oe tnougnt 1 Operation Period with Water Supply > the Demand In this condition it is easy to manage, though generally less water efficient than what has been anticipated during tne design phase could be practiced. This condition could be met during the peak rainfall season for the two seasons (Belg (March to June) and Meher (Sept to December)). In Late April and May for the Belg season and in September and October for the Meher season, supply of the Baie-Gadula project is likely to exceed the demand as in general case It can be possibly concluded that in such periods of project operation system efficiencies are likely to be undermined Dunng such periods of farm operation it is important that irrigation efficiencies shall be monitored thorougnly Farmers imgation practiced snail be closely monitored and assistance for attaining proper efficiencies shall be made 2 Operation Periods with Moderate Water Deficit This is the case by wmch water scarcity is moderate and not severe The months of October and November in the Meher season and May & June in the Beig season are expected to have sucn condition On the otner nand, moderate deficit (80-90 percent of the requirement) often encountered and occurs periodically either as realty of a dry year or within a year at peak requirement times Improving WWDSE Affdis Ababa in Association with 46- Detail Design of Bale Gadula irrigation & Drainage Project iCTP^t Ltd anr^BCEPLC October 20HMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section - l Volume - VII Operation and Maintenance Manual operation practices can significantly improve the situation. Enhancing project efficiency and others can De included as improved practices 3 Operation Periods where Supply is significantly less than (potential) the Demand: Such condition can be encountered due to unprecedented hydrologic variability including in season variability and when actual cropping pattern is significantly different from the planning and/or designed cropping pattern etc In the case of Bale-Gadula the design cropping pattern is 180%, in practice however the cropping pattern could be raised to 200% which might brought water scarcity in to the system The months of Feb/March in the Belg season and Dec/Jan in the Meher season are expected to face such conditions more frequently 4.10 Matching Supply and Demand under Limited Supply Conditions A number of factors can affect availability of water supply in irrigated agriculture systems Scarcity may prevail due to unprecedented hydrologic variability that may not captured in evaluating the dependable flow it can be due to expansion of the command area and adoption of high cropping intensity (higher than the design value) it can be due to inefficient system operation which mostly causes scarcity n me downstream ~sers ana etc Under sucn limited supply conditions come oemnent measures snail oe thought to correct the situation and match the supply ana aemanc side tor me system The primary concern snail be to understand the situation mat causes the supply to be limited and once this condition is understood various measures mat would be taken are largely related to - i) The cropping oattern li) The water distribution practices iii) The water fees I. Cropping Pattern Related Measures Regarding the cropping pattern to reduce the demand side of the system and match with the supoiy the foiiowmg measures can be considered. a; Change planting time oerform staggering of crop seeding time which can neip to reduce peak water requirements b) Change existing crops of high water demand with tnose having less water consumptions such as changing sorghum for maize for instance that reduces water demand Such attempt may nave challenges as farmers may not wish to cnange for otner reasons (market price low not familiar with proposed crop etc ) Thorough discussions with the farmers ano some arrangements like securing market outlets can be considered as a means to tackle the challenge ci Reduce Irrigated Area This attempt can De tnought both pnysically and technically Physical measures induce reducing the size of the command area pnysically Dy avoid.ng some areas oy establishing some criteria sucn as WWDSE. Addis Aoaba m Association with -47- Detail Design of Bale Gaduia Irrigation & Drainage Project iCT Pvt ^td and AEOE P‘ ? October 20nMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual command areas with poor soil conditions or some areas located in the further d/s reaches of the irrigation system etc. can be avoided. The abandoned areas can be developed by rainfed system only Technically this can be attempted by thinly spreading irrigation water over wider area. In such conditions the pnnciples of yield-water response of crops (FAO Irrigation and Drainage Paper No, 33) can be utilized The peak demands of a crop along its growing season can be identified and at least one or two irrigation for that important period of the cropping season can be secured and in other periods of the cropping season where the crop is less sensitive to moisture stresses, irrigation can be thinly distributed in a wider area. This attempt coupled with the first attempt (staggering the cropping pattern) can be more effective in aoing supply-demand matching exercises Losses in production while distributing water thinly in a wider area can be estimated employing the procedures and data presented in FAO No-33. The limits for affordable losses can be extended up to 20% to 30% in some adverse conditions. Difficult to do, but farmers will do anyway if supply is low May reduce area, or spread available water more thinly. Can eliminate areas farthest away from water supplies, areas with poor soils, poor levels of maintenance, limit supply to designated areas only, annual rotation of areas which are to receive water, other areas grow ram fed crops. II. Water Distribution Practices Related Measures To reduce demand can either (a; reduce the water allocation or (b) change the method of distribution to a more efficient one (a) Reduce water allocation by Allocating Water to Preferential Crops Common where high value crops are grown with less valuable crops. In the case of Bale-Gadula. for instance sugar cane is designed to be part of the cropping pattern. If sugar cane is decided to be part of the actual cropping pattern of the beneficiary farmers, and if the system scarcity is facing, then priority of allocation can be given to sugar cane than the others In such condition sugar cane is considered as preferential crop Decrease Quantity of Water per Irrigation Allocate supplies proportional to gross area (very basic) or proportional to crop requirements Alliteratively allocate preferentially to crops in sensitive growth stage (further details for yield-water response can be referenced to FAO 33-yield Response to Water) Extend Interval between Irrigations This is the case where scneduling can be doubled or increased by some proportion so that number of irrigation can oe reduced For instance if total number of irrigation in the growing season is designed to be 10, then by doubling tne scneduling 5 irrigations can be done or three irrigations can be omitted and seven irrigations can De made This can be done by securing tne WWDSE Addis Abaca in Association with 'CT °vt Ltd ind ABCE &LC ■48- Detail Design of Bale Gaaula Irngation & Drainage Project October 2011Ministry of Water and Energy - Section -1. Volume - VII Federal Democratic Republic of Ethiopia_____________________________ Operation and Maintenance Manual design schedule for sensitive growth stage of crops like the flowering stage and reduce number of irrigations in the growing stage where the crop is less sensitive for moisture stress such as in the maturity stage after flowering stage (b) Change Water Distribution Method This attempt can be difficult to implement since one water distribution method is adopted for the system during the design phase However, in the case of Bale-Gadula the 24-hrs irrigation application at tertiary levels can be changed to 12-hrs if farmers' irrigation practice is enhanced to be more efficient. In the case of Bale-Gadula rotation water distribution method is adopted at tertiary level Each tertiary will have its own turn in the rotation system. To some extent this kind of water application can be the source of system inefficiencies Farmers may get tired staying the whole 24-hrs irrigating their plot if they are not arranging it by shift among the family of the household This arrangement can oe reduced to 12-hrs a day if farmer’s capacity in holding a number of furrows at one time is increased and/or doubled. To accommodate increased discharges free boards at tertiary level can be utilized and also some amendments can be introduced III. Water Fees Increasing water fees tends to decrease amount of water used. It is difficult to do. however it needs careful planning This will require measuring devices and back up account in system. Farmers need to understand soil-plant-water relationships Conducting more training activities can help to smoothly exercise such methods. 4.11 Methods of Water Distribution There are a variety of methods by whicn water can be distributed in an irrigation system The main categories are • Continuous flow • Rotational Flow • On-Demand flow (i) Continuous flow As the name implies the delivery Pont" receives a small, but continuous supply of water throughout the season which matches (or attempts to match) the daily irrigation requirements The “delivery point’ may be tne crop itself or it may be a tertiary unit intake (ii) Rotational flow In this case irrigation supdies are rotated between delivery points with canals running at full or partial discharge or close The element of time is introduced or closed The element of time is introduced the volume delivered is dependent on the discharge and its duration (iii) On-Demand flowMinistry of Water and Energy - f-ederai Democratic Republic of Ethiopia Section - /, Volume - VII Operation and Maintenance Manual Here the supply can be continuous or intermittent it is entirely up to the demands made at the point of delivery This method of water distribution could be difficult to apply in the context of our country, as a result it is not considered as an alternative both at the design and the operation phases In the case of Baie-Gadula irrigation system the first two methods (continuous and rotation) are mixed Continuous supply is used at mam and secondary canals level The two main canals and the respective 13 secondary canals (five in the left bank and 8 in the right bank) are designed for a continuous distribution Ternary canals are designed to accommodate rotational distribution method. The capacity of the tertiary canals is designed for 12-hrs irrigation capacity and when the farmer is at his/her turn will exercise irrigation for 24-hrs 4.12 Irrigation Schedules irrigation schedules are expressions in terms of frequency, rate, and duration of how water is diverted or delivered to a farm unit (Replogle ano Merriam, 1980) Schedules can be broadly divided into two types • Rigid Schedules • flexible Schedules Frequency rate and duration are the three imoortant design variables that should □e given due attention wmle doing irrigation scheduling activities. Rigid Schedules: - Rigid, predetermined supplier controlled schedules are - • Constant amount, constant frequency • Constant amount, variable frequency • Varied amount, constant frequency Constant Amount, Constant Frequency: In the case of constant amount, constant frequency, constant amount of water is delivered at constant frequency This method of schedule is known as rotation scneduling Crop water requirement is mostly less than the delivered amount resulted from the different level of water abstraction by different crops in tne system Constant Amount, Variable Frequency in this case water quantity delivered is constant but the frequency is variable depending on the soil type and development stage of each crop within the piot under consideration This method of scheduling is Known as variable frequency rotation Varied Amount, Constant Frequency in this case water quantity delivered is adjusted and made variable based on the irrigated area, level of crop abstraction etc but frequency is assumed to be constant This scheduling usually known as Varied amount rotation. Case(i) is simple to administer and easy application It needs less management requirements However since both water quantity and frequency are constant planning could oe conservative which may nave considerable losses in the system Care snouic be taken in applying a constant amount of water at constant ”"h ' -5°- Dera" Dcsign ot Bale Gadula lm^on &~Dfwnage~Project October 20 VMinistry of Water ana Energy - Federal Democratic Republic of Ethiopia Section - /. Volume - VII Operation ana Maintenance Manual frequency Time of irrigation shall be properly managed to enhance system efficiencies of such scheduling method This metnod of scheduling is widely used in public irrigation projects like settlement projects Irrespective of the supply variability within the system, constant amount of water is delivered to each tertiary □mt to run at constant frequency In the case of case(n) water delivery is constant but frequency is variable Frequency variaoility is to account the crop type in eacn plot, and the abstraction level of each crop within the growing stage This scheduling method if administered properly can enhance better system efficiency compared to case(i) Losses in the system can De reduced This kind of scheduling can be considered as the next step for the Baie-Gadula irrigation project. As experiences of system operation is acquired Doth Dy the farmers and the PMU it is possible that constant amount of water can De delivered to each tertiary units but frequency can oe variable for each plot in the tertiary unit based on the crop type and its aevelopment stage soil type and other parameters like climate However, at the mitiai project operation period (first five years for instance) case(i) can be adopted oy employing different measures to ennance system efficiencies However the last case (case (hih is dynamic m nature and more efficient Put much more difficult to manage it neecs rigorous planning process. Flexible Schedules - tms Kina of scneauiing metnod is usually known as on- demand schedule and it is user-controllea. though there is often a need for compromise between tne water delivery agency and the farmer The various forms of flexible Scheduling can include (i) demand (ii) Limited rate, demand (iii) Arranged (as to date), (ivj Limited rate arranged (v) Restricted-arranged (in wmch ootn the rate and duration are fixed ana emam constant as arranged), r (vi) Fixed duration, restricted arranged scneauie (in which the fixed duration is set by policy jsually 24 hours and tne date and constant rate are arranged) This kind of scheduling is difficult to De appliec especially in public irngation projects like Baie-Gadula 4.13 Irrigation Scheduling in the Baie-Gadula Irrigation Project 4.13.1 Irrigation Time Irrigation time indicates the time of irrigation application Der day In the case of Baie-Gadula irrigation project, irrigation time per day is fixed to be 24hrs at all levels of the command system This variable is understood to De the duration of irrigation in the rotation system This duration is adopted to reduce costs of conveyance structures including main and secondary canals in the system Moreover since base flow abstraction is made using diversion structures irrigation duties shall be as small as possible to cover more command areas Irrigation time or duration is fixed to be 24-hrs for the system The atorementioned cases were taken as a oasis for fixing irrigation time/duration to De 24-nrs at all levels of the irrigation system IVWDSE Addis Ababa in Association v/ifH .5- ; D^inn of Bale Gaduia imaatton & Drainage Proiec'Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 4.13.2 Tertiary Unit Level Scheduling Section -1, Volume - VII Operation and Maintenance Manual Rotation water distribution method at constant amount and constant frequency is adopted at tertiary unit level. Mam and secondary canals are designed for 24hrs supply while TCs are designed for 12hrs supply, subjected for rotation. The SCs are used to run the rotation of the system meaning rotation is performed within the block. Each secondary canal forms a block in the system. The 24-hrs supply from the SCs is arranged to rotate in the TCs by taking the SCs inflow in to the TCs arranging the number of TCs that can carry the 24-hr supply of the respective SCs in one group. In this method it is assumed that the user will be forced to work 24-hrs per day by the time his/her turn is set on. In this system the capacity of the tertiary canals will be doubled as the transformation ratio of the base hydromodule to the rotational hydromodule will be doubled Irrigation scheduling is designed at two levels, (i) at tertiary unit level and (ii) at individual crop level. Tertiary unit level scheduling is made using the outputs of the USDA-SCS irrigation system methodology The USDA-SCS irngation system methodology simulates optimum furrow inflow, furrow slope, length of furrow, intake opportunity time for furrow to infiltrate a given depth of application, and system losses such as deep percolation and runoff losses. These design parameters as computed for each soil intake family employing the aforementioned design methodology, is used to perform scheduling at tertiary units level The summary of the salient features of irngation system design for the project, as it is used in the scheduling of the tertiary units, is presented in Table4.4 Moreover, to perform similar scheduling practices during project operation, soil intake families including the modeling activity are included in Volume-Ill, Appendix-ll of the detail design report of the project Summary of salient features for different soil intake families available in the Bale-Gadula command system are presented in Table4.3 for quick reference purposes. These data can be used as an initial data to start/plan scheduling activities. However, for actual scheduling activity during project operation phase, data shall be collected using ring infiltrometer Table 4.3 : Summary of Soil Intake Family Salient Features Soil Profile Intake Pit No Family Soil intake Family Constants ab cf A g*(10 -4) | BGP-05 2.0 2.753 0 808 70 10.650 7 451 BGP-18 1 5 2 284 0 799 7.0 9 760 5.819 BGP-34 08 1 560 0 773 7.0 8 500 3.535 BGP-35 0.2 0 777 0 699 70 7430 1 578 BGP-39 02 0 777 0 699 70 7 430 1 578 BGP-48 02 0 777 0 699 70 7 430 1.578 BGP-53 1 5 2 284 0 799 70 9 760 BGP-C8 1 5 2 284 0 799 70 I 9 760 5 819 | 5 819 I WWDSE Addis Ababa m Association with -52- Detail Oesign of Bale Gadula Irngation & Dramaoe Pmivrt ICT P.t Ltd and ABCE PLC Qcf^erMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual Table 4.4 : Features of the Irrigation System Furrow Characteristics Simulated Employing SCS Methodology Application depths (mm) Applic Losses ation (mm) Soil Intake Family Simulated through Modeling 2.0 1 6 200 0 75 0.75 004 55 00 130 80 60.00 83 70 20.20 350 72 15 i 1.3 200 0 75 0 75 0 04 57 60 164.10 60.00 85.30 14 90 10 50 70 1 1.0 08 200 0.75 0 75 0 04 7560 255 80 60 00 81.90 11 80 10 10 73 08 06 200 0 75 | 1.00 | 0 04 7640 334 50 60 00 80.30 8.20 12 00 75 0.5 03 200 0 75 I 0 75 0 04 179 50 679 00 60 00 81 50 10.60 10 90^ 74 0.2 02 200 | 0 75 1 00 ----------L 0.10 130.40 284 30 60 00 85 30 | 17.90 7 40 70 4.13.3 Irrigation Scheduling at Individual Crop Level Irrigation scheduling for individual crops shall be made by writing the water balance at the canopy of the crops envisaged in the cropping pattern of the project The soil moisture characteristics curve as developed specific to the soils in me command area of the project are used to write the water balance and daily time scale shall be used in the simulation exercises. Data collection to establish the soil moisture characteristics curve for each tertiary unit shall be made and analyzed in the laboratory In the design phase, the soil moisture characteristics curves are made at seven points (refer Table 2.6 in section 2.0 of this report) to nelD the discretization process while writing the water balance at the canopy of eacn crop The water balance equation used for scheduling individual crops is presented as. IWR = Fg - p ff + ETc ±Gs- SR Where c AS - Change in moisture storage at the crop canopy Fg - Gross Depth of Application Peff = Effective Rainfall; ETc - Evapotranspiration for a specific crop, Gs- Soil water movement as capillary fringe and deep percolation, and SR - Surface Runoff Detailed design procedures can be referred to the design report (Volume III, Appendix V) WWDSE Add s Ababa in Association with -53 Detail Design of Bale Gadula Imgation & Drainage Project •’ -< . - P'_C 3'tobe' . ' Inflow (l/s) Length (m) Spacing (m) Slope (%) Manning Roughness (n) Advance Tlme(min) Intake Opp Time o > (min) Net Depth Gross Depth Deep Percolation i __ Runoff Application Eff(%)Ministry of Water and Energy Federal Democratic Republic of Ethiopia 5. OPERATION AT CONTROL POINTS 5.1 The Principles of Control and Operation Section -1, Volume - VII Operation and Maintenance Manual In the operation ot an irrigation scheme supplies of water need to be taken from an aDstraction point (Weybriver in our case) and transported to delivery points located at various reaches and levels in tne command system Canals are required to transport the water to the fields, drains to remove excess water Various auxiliary structures (bridges, siphons, culverts) are required to ensure tne unhindered passage of the canal round or through potential obstacles (roads, valleys drainage paths etc) or to accommodate excessive ground slopes (canal falls) The ability to manage and operate the system is dependent on control structures, such as diversion weirs & head regulators at the river diversion point, cross and head regulators located at various levels of the canal network of the command system, and associated measurement structures In the preceding chapter detail procedures and guiding principles are presented regarding crop/irrigation water requirement simulations and irngation scheduling activities However, these simulation works ana schedules are only as good as tne design of tne irrigation system allows in controlling the flow There are many widely divergent principles of system design, some allowing very simple operation of the system, others requiring fairly complex operation procedures. In gene'ral terms it is thought that the simpler the system, the less control and the less possibility of matching crop water requirement accurately with supplies. The more complex, the more control, and the more possibility of matching crop water requirements can be accurately with supplies 5.2 VariaDles for Control To control an irrigation system it is necessary to regulate three variables: (i) water level, (ii) discharge and (lii) period of flow Regulating Water Level:ln order to command and thus irrigate the land the water level in a canal must be maintained at an appropriate level At a turnout from a parent canal (PC) (could be main canal or secondary canal), the water level must be sufficiently high to command the highest or most distant irrigable plot in the off-taxing ternary unit This is generally achieved in one of the two ways. (a) A cross regulator is constructed in the parent canal to raise and maintain the water level at the design water level (DWL); (b; The water level in the parent canal is maintained at DWL by virtue of the discharge in tne parent canal. The canal is sized so that at a given discharge it will allow flow at normal depth and thus command tne tertiary unit off-takes Regulating Discharge: Discharge in the system can be regulated by (i) a gate (ii) the size (width or diameter) of tne turn out and (iii) adjustment of upstream water level or head difference across tne turnout by varying tne deptn of flow in the upst eam canal, usually implemented using head regulators Gates can take r WWDSE Audis Ababa in Association with -5*- Detaii Design of Bale Gtidula Irngation & Drainage Project iCT Pv Ltd mnABCE^LC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I volume - VII Operation and Maintenance Manual many forms from vertical lift gates giving multi-vanable gate settings, to simple on-off gates Regulating Period of Flow (Time):For crop water requirements we are referring to the volume of water Volume is a function of time and discharge, therefore both required to be measured For continuous flow deliveries if a discharge reading is taken once a day then that discharge is assumed to apply for 24-hrs For rotation or intermittent flow it is necessary to measure both the discharge and the period of flow to determine the volume supplied 5.3 Control Points in the Bale-Gadula Command System The irrigation system layout including the controlling points of the Bale-Gadula Irrigation Project is summarized in section 2.3 of this report The design principle followed while fixing control points at various points is based on the pnnciple of controlling canal inflows at least at tertiary unit levels It is composed of a controlling point at the diversion point using head regulators at both banks of the river flow measurement possibilities at the entrance of each block (head of secondary canals) and at tne entrance of the tertiary units (head of tertiary canals) At the headwork level the head regulator on the left bank of the river is designed to have two measurement structures (one broad crested weir and partial flume' and head regulator to regulate the head of the canals inflow At the division boxes tne control points are designed to have a proportional division box combined with gated onfices Eacn division box is designed to constitute (i) head regulator at the head of the off-taking canal to control u/s water level (ii) cross regulator at the parent canal to maintain water surface level in the parent canal and (iii) broad crested weir to measure discharge passing through the gates Each division box in the system is subjected for two forms of flow (i) orifice type of flow largely wnen the parent canal is subjected for high stage flows and (ii) weir type of flow when tne parent canal is subjected for low stage flows The design of the division boxes is arranged in such a way that discharges measurement activities can be performed using orifice formula during high stage flows and head regulating activity can be perrormed by adjusting onfice openings In similar fashion broad crested weirs can be used to measure discharges and gates can oe used to regulate heads across the system By this design it is possible tnat in the Bale-Gadula command system inflows entenng each block and each tertiary unit in the system is measured and quantified. Head is also regulated and possible to maintain to the required level Flows at all abstraction points in the canal network are measured and regulated. 5.4 Stage Discharge Curves at the Headwork 5.4.1 Stage-Discnarge Curve for the Sluice Gate In the Baie-Gadula project headwork arrangements the sluice gates are also acting as a cross regulator especially at low flow conditions As stipulated in the design works of the design report (Volume II of the detail design report of the project tne sluice gates act as an orifice During low flow conditions tne water tWVDSE Add/s Anaoa Association '.'.it" 55- ~rp . .- ->etail Design of Bale Gaduia /rogation & Drainage P n<p. • rMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I, Volume - VII Operation and Maintenance Manual surface of the river inflow can be maintained to the full supply level by adjusting the openings of the orifice at the sluice gates The discharge formula per meter width of the sluice gate is presented as: </ = Cj -E.) Where q= discharge through the sluice gate per meter width (cumcs/m) C discharge coefficient for the orifice (rectangular orifice) ta*en as 0 61, a Y, is u/s flow depth (m); and Y3 is d/s flow depth (m) Taking the clear span of the sluice gate as 2 50m and discharge coefficient as 0 61 the stage discharge curve for the sluice gate is presented in Figure 5.1 Figure 5.1: Stage-Discharge Relationship of Sluice Gate “1— Stage (m) During actual operation the discharge passing through the sluice gate shall be caliberated and the discharge coefficient at various heads shall be established It is also imperative that the caliberation shall be made both for the free flow and submerged flow conditions The sluice gate bay is separated from the wier bay using guide walls extended to the downstream sill of the stilling basin The suice Day can be usea to perform the caliberation process Current meters can be used t measure discharges at various openings of the sluice d/s of the sluice gate 5.4.2 Stage -Discharge Curve for the Head Regulator As indicated in the preceding section, tne head regulator for the Baie-Gadula system is designed to have two measurement structures. The Stage-Discharge curve for the two measurement structures is established and presented here taking an average conditions for some of the design variables such as the discharge coefficients During actual operation caliberation shall be done for both structures so that the discharge coefficient under various inflow heads can be fixed ana discharge measurement and regulation works shall be made based on tne newly established stage-discnarge curves The stage-discharge curve WWDSE Addis Ababa m Association with -56- Detail Design of Bale Gadula Irrigation & Drainage Project ICT Pvt Ltd and ABCE pLC October 20"Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual presented here in this manual is merely for illusteration purposes Current meters shall be used to effect the calidberation process 5.4.3 Stage-Discharge Curve for the Broad Crested Weir Classified under the term ‘broad crested weirs are those structures over which the streamlines run parallel to each other at least for a short distance, so that hydrostatic pressure distnbution may be assumed at the control point To obtain this condition the iength in the direction of flow of the weir crest (L) is restricted to the total u/s energy head over the crest Among the vanous forms of the broad crested weirs the horizontal broad crested weir is used as a discharge measurement structure for the head regulators of the Bale-Gadula headwork system. The discharge through the horizontal broad crested weir is evaluated using a general formula presented as O = 1.7BW‘5 Where Q is discharge passing over the broad crested weir (cumecs): B is Crest length of the broad crested weir at the control point (m, taken as 2m) H is upstream head over the crest of the broad crested weir As discussed in the preceding section, it is imperative that calibration shall be run to establish the actual stage-discharge relationship for the broad crested weir inserted in the Baie-Gaduia heaawork system. For illustration purposes, taking an average conditions for the discharge coefficients (Cd = 1 70). the stage-discharge curve for the broad crested weir is established and presented in Figure 5.2. Figure 5.2:Stage-discharg curve for Broad Crested Weir at the HeadRegulator 7 M/VDSE Addis Ababa in Association with -5 Detail Design of Bai* Gadula Irngation & Drainage P •Ministry of Water ano Energy - Federal Democratic Republic of Ethiopia 5.4.4 Stage-Discharge Curve for the Partial Flume Section -1 Volume - VII Operation and Maintenance Manual Parsnail flumes are calibrated devices for measurement of water in open channels The flume consists of a converging section with level floor as its inlet, a throat section with a downward sloping floor and a diverging section with an upward sloping floor On the basis of throat width partial flumes are classified into three categories, very small having a throat width of 1, 2 and 3 inches i.e 2.5, 5 0 & 7 5 cms. Small flumes have throat width of 6 inch (15 cms) through 8 ft (2.5 m). The partial flume designed for BAGID project is grouped in this second category It has a throat width of 8 ft (2.5 m) Throat width of large flumes varies from 10 ft (3.0 m) up to 50 ft (15 0 m) The upstream head-discharge (ha-Q) relationship of Partial flume of various sizes, as calibrated empincally is represented by an equation, having the form Were K denotes a dimensional factor which is a function of the throat width. The Power u vanes Derween 1 522 and 1 60 Partial Flume designed for the BAGID project has a discnarge equation of the form 0 = 6.112^'607 This flume has a discharging capacity that ranges from 0 0972 cumcs to 3 949 cumcs Detailed computation of tne various hydraulic dimensions of the Partial Flume is presented in Volume IV of the detail design report of the project. The stage-Discnarge curve for the Partial flume at the head regulator of the Bale- Gadula headwork system, as computed employing the above formula is presented in Figure 5.3 Calibration after construction is important to establish actual stage-discnarge curve for the Partial flumes in use Figure 5.3; Stage-discharge Curve for the Partial Flume Located at the Head Regulator WWDSE Addis Ababa in Association with /< '‘rDir Ltd and ABCE PLC -58- Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Ministry of Water ana Energy - Federal Democratic Republic of Ethiopia Section -1, volume - VII Operation and Maintenance Manual 5.5 Stage - Discharge Curves at the Division Boxes in the Canal Network For irrigation water distribution works from the mam canal to secondary canais and from secondary canals to tertiary canals simple proportional division boxes combined with gated orifices are selected In this division boxes gated orifices are combined to effect discharge measurement mechanisms for better regulation of the canal system so that efficient system operation can be developed during the operation of the project. These division boxes are designed to act like orifices by providing gates and they are called as gated orifice outlets The advantage of providing a gate for these division boxes is to allow more precise regulation of the discharge rate both in the upstream and downstream reaches of the canal network Regulation work at all division boxes of this type is done by varying the size of the onfice opening both along the off-taking and parent canals in the system during high stage flows of the canal system and by having discharges over the weir system at low stage flow of the canal system. The orifices/gates in the parent canal (such as the MCs while SCs are off-taking and the SCs while the TCs are off-taking) are largely functioning as a cross regulator by regulating flow head in the division box system so that required amount of canal discharge can pass to the respective off-taking canals The orifices/gates in the off-taking canals are designed to measure discharges entering the respective off-taking canals and function as a head regulator The head driving the discharge entenng the respective off-taking canals is regulated using the opening of these orifices/gates More efficient discharge measurements can also be achieved by fixing the discnarge coefficient for every particular opening by undertaking proper calibrations in the future at the time of project operation To assist this calibration orocedure a permanent oenchmark is assumed to be establisned within 10 m or less distances from each structure in :he system during the period of construction It shall be noted that benchmarks shall not be placed closer than 2 0m from the measuring point for reasons of surveying requirements Discharge Evaluations: The hydraulic conditions of gated division boxes is identical to the cases of orifices, so that hydraulic equations developed for orifices is used for the discharge evaluation of these structures. A free falling flow condition is selected in the design of these structures as these structures are dominantly usee as an inlet both for secondary and tertiary canals where head is not a limitation The free falling flow has also the advantage of making the outlet modular in whicn the discharge is dependent only on the upstream water level A free flow orifice discharge equation for rectangular gate having a gate opening b and width w is expressed as follows assuming the dimensionless velocity head coefficient is unity which is true for approach velocities less than 1 0 m/s Q=C f] Where 2 mi = is tne area A of an orifice opening (m ) i/VVVDSF Aodn Abano in Association with -59- Detail Desia^ of 9a*e Gadula irrigation & Drainage & oject rMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual h u = the upstream flow depth which can be measured anywhere upstream from the gate, including the upstream face of the gate, since the value of hu (given in m) varies a small amount depending on the location chosen for measuring it. C = is tne discharge coefficient, where an average value of 0 61 for design purposes (fully contracted rectangular orifice) is used However, for measuring purposes the exact discharge coefficient should be determined by proper calibration for each orifice area during project operation 2 g = acceleration due to gravity (9 81m/s ) Gated division boxes can act as an orifice if and only if the upstream water depth is designed in such a way that it should be greater than the possible maximum vertical; opening of an orifice for any given particular discharge. In the design process this oasic design criteria is given due consideration and the value of hu for eacn discharge is made to be 30% more than the vertical opening of the orifice b It is believed that for the change that will happen at the time of calibration due to the change of the discharge coefficient this value will be enough to keephu always greater than the possible maximum orifice opening. At this eno it shall be noted that if tne upstream flow depth, dunng operation, is made to happen below the gate lips at any particular discharge, the structure acts as free flowing weir and the discharge equation to be used for its evaluation ano calibration should be the formula for weirs not for orifices. In the case of Bale-Gadula SSI project all secondary and tertiary off taking points are arranged to have more than one orifice that would operate at the same time. Due to this arrangement the wetted area of the box in each case is designed to have a dimension of ten times the maximum orifice opening area in the arrangement. The width and breadth of all division boxes in the system are arranged to satisfy this design criteria Detail design works are presented in Volume IV of the detail design report of the project. The summary of division boxes distribution by type in the Bale-Gadula command is presented in Table 5.1 Taole 5.1 : Profile of DBs in the BalaGadula Command System DBs Category BDs on MC-1 DBs on SCs Total for the Project T ype-A 4 2 6 Type-B 15 88 103 Type-C 7 59 66 Sum 26 149 175 The stage-Discnarge curve for the broad crested weir at head regulator is presented in Figure 5.2 Actual curve for each structure at each location shall be established Dy undertaxing calibrations Taxing average conditions ana width of 1 WWDSE. Addis Ababa in Association with -60- Detail Design nf Bale Gadula Irrigation & Drainage Project ICT Pvt L'd mdABCEPLC October 20 VMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section - /. Volume - VII Operation and Maintenance Manual m the stage discharge curve for orifice flows of the division box is presented in Figure 5.4 merely for illustration purposes For calibration, current meters can oe used in the main canals and calibrated Parshall flumes can be used for division boxes on secondary canals Figure 5.4 : Stage-Discharge Curve for Orifices in the Division Boxes /--------------------------------------------------------------------- ------------------- \ _____________________ .________ ;____________ 2 5.6 Discharge Measurements Discharge observations on main canal and branches shall be carried out at least once in a day during irrigation seasons At the diversion work and during the wet penoa discharge measurement shall be made twice a day one time at 8 0 AM and at 6 00 PM in the afternoon Percentage to normal discharge should be revised from time to time for purposes of regulation and distribution of water In case of high seepage losses in the mam canal, suitable remedial measures should be taken to reduce it. Measurement structures at control points and current meters in reaches where discharge measurement structures are not available should be used for observation of discharges. Where such facility is not available or where depth of water in the channel is insufficient, floats may be used. WWDSE Audis Adana in Association with _ r r • _ J r : AS ZE lC c -6,. Detail Design of Bale Gaduia Irrigation & Drainage Pr iiect Octob?- ZOt'Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 6. INSPECTION OF WORKS Section -1. Volume - VII Operation and Maintenance Manual The following is given a description of Inspection related matters 6.1 Diversion Structure 6.1.1 General Inspection of barrages and weirs is necessary to obviate the possibility of extension of damage Such inspection should usually be carried out annually for all under water works after monsoon by means of underwater lamps and sounding roos. In addition, detailed inspection in stages should be earned out after drying the upstreamfloor by isolating portions of the barrage such that each portion is thoroughly inspected against nay crack or damage, once every five years While doing so, the embankment should be placed suitably upstream of the impervious floor for pressure relief and the divide wall or pier and adjacent floor provided with temporary strengthening to the extent required. The repairs as necessary as a result of inspection should be carried out well before the onset of the next monsoon. Any serious defects noticed should be reported to appropriate authorities and decisions taken in time The inspection and maintenance may broadly be classified under the following items' a) Aprons 1) Upstream apron and area immediately upstream of it, and 2) Downstream apron and area immediately downstream of it. b) Impervious Floors 1) Upstream of tne gates/falling shutters, and 2) Downstream of the gates/falling shutters c) Canal Head Regulator d) Instrumentation and Performance e) River Training Works 6.1.2 Aprons The sounding and probing in the area shall be undertaken every year immediately after the monsoon in order to assess tne scours and launching of aprons in the vicinity of structures. The non-launching portion should be carefully examined particularly on downstream, to ensure the effectiveness of inverted filter 6 1.3 Impervious Floors A thorough inspection of upstream and downstream floors shall be done immediately after the wet season The upstream floor shall be inspected every year early in the cold weather season oy probing and the use of underwater lamps A careful inspection of joints of the stone-sets should De done where sucn WWDSE Addis Ababa in Association with -62- Detail Design of Bale Gaduia irrigation & Drainage Project Pvf Lrd and ABCF °LC October 20' 1Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I Volume - VII Operation and Maintenance Manual structures have been carried out in boulder reaches Minor repairs can be done under water whereas major repairs may be undertaken by isolating the area The downstream basin shall also be carefully inspected in the cold weather season and the repairs carried out well in time before the onset of Belg and/or Meher seasons In case of deep cisterns requiring expensive cleaning and dewatering, inspection of sandy nver reaches can be carried out by probing but in boulder reaches where this may not be possible, dewatenng, cleaning and repairs may be carried out by rotation once in three years. The condition of boulder-set or granite block in the case of boulder Stage River should be carefully examined, and repairs and replacements made, as found necessary While dewatering deep downstream basins, care shall be taken to ensure that the design uplift for such condition is not exceeded This shall be clearly specified in the regulation order 6.1.4 Canal Head Regulator The work shall be carefully examined every year in the cold weather by probing in case of upstream floor and examination under dry condition of downstream floor during closure or isolating the area where closure may not be possible Visual inspection of upstream floor should also be carried out once in three to five years by isolating tne area. All necessary repairs shall be carried out in time 6.1.5 Performance of Structure The performance shall be evaluated as below 6 15 1 Uplift Pressure The pressure observation pipes are embedded in the weir or barrage structure generally in piers, and flank walls in sucn a manner as to give representative uplift pressure along and immediately beneath the honzontal floor, at different points along the vertical cut-off Additional Dressure pipes may be installed, if required, to determine uplift pressure at critical points in stratified foundations. The pipes shall be numbered and a permanent record of observations shall be maintained The observed uplift pressure should be compared with the design uplift pressures with the help of a graphical plot and any needed remedial measures adopted. Frequency of observation will depend upon local conditions It may generally be enough to take observations once a month during monsoon period and more frequently during the non-monsoon period It shall be ensured that: a) The mouths of all pipes are kept closed by caps to obviate the chances of foreign matter finding its way into the pipes and clogging them b) Each pressure observation point is given a distinct number and c; Eacr. pipe is frequently tested to ensure that its strainer is not choked This can De best done with the help of an ordinary hand pump by working it till water comes out freely WWDSE Addis Ababam Association with -63- Detail Design of Bale Gadula Imqatico & Drainage Project *-1? ?:tober 201'Ministry of Water and Energy - Section - I. Volume - VII Federal Democratic Republic of Ethiopia _________________ Operation and Maintenance Manual 6.1 5.2 Hydraulic jump profile Strip gauges should be painted every 10 m on the wing walls and the long divide walls to observe the hydraulic jump profile in the prototype under different hydraulic conditions The following observations shall be taken aj Upstream water level b) Downstream water level- before jump and after the jump Also thedepth of sediment on upstream and downstream floors should be measured 6 15 3 Suspended Sediment During the Beig/Meher season, water sample should be taken in accordance with IS 4890 1968 simultaneously upstream and downstream of the under sluices and in the canal below the head regulator to assess the suspended sediment therein Such observations should be taken at least once a week (closer intervals in case of nigh sediment side Similarly, the survey on downstream side concentration; to judge the efficiency of sediment should extend to a length up to which river bed exclusion and to decide if any change in the mode changes occur Sufficient number of permanent gauges or other reference marks should be established on both banks to facilitate superimposition of old and new survey The cnanges in tne river course snail be examined and remedial measures should be taken 6 15 4 Settlement and remedial measures In case of Baie-GaduiaDiversion structure settlements are not expected in view of tne structure being founded on rock. 6.1 5.5Aggradations upstream The river bed upstream of the barrage of weir is likely to aggraded resulting in increased afflux and reduction in freeboard provided in design To determine the increase in the afflux, if any gauges should be established on the upstream, one immediately upstream of the work and one each at 500m and 1000 m upstream of the first, and observed regularly The necessity of raising/constructing any afflux Danks may nave to oe considered to restore the designed freeboard. 6 15 6 Discharge distribution and cross-flow Observations snould be taken to find the discnarge distribution through different bays of tne weir proper If there is significant cross-flow and/or difference in discharge intensities through different bays remedial measures should be taken to check this tendency for wnich improved regulation may be a great help 6 15 7 Pond Capacity A detailed river survey covering tne headwork/weir and river training works upstream and downstream shall be carried out every year The survey snould extend about one meter above the design flood level on both tne banks on upstream A/WDSE Addis Ababa in Association with iC P-.'f Jd and ABCE L ~ r P -64- Detail Design of Bale Gadula irrigation & Drainage Project October 20'"'Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 6.1.6 Operation and Regulation Section -1. Volume - VII Operation and Maintenance Manual Adequate regulation staff should be provided and their duties should be clearly specified Adequate stocks of stores, tools and plants required to meet emergencies should be maintained on all barrages and weirs These should be listed in detail in the regulation orders and their availability checked periodically by the engineer-in-charge. The gauge sites shall be linked by a telephone or wireless or internet generally both with the head works. In general, operation of the barrage gates snould ensure the following features: a) The required pond Level is maintained both during the non-imgation flows and the falling flood periods b) The non-irrigation flows remain near the under sluice bays so that feeding of the canal through the head regulator is not affected c) A fair uniform distnbution of discharge along the width of the weir bay is obtained as far as practicable d) Parallel flows both on the upstream and the downstream of the weir proper is avoided at all times as far as practicable e) The risk of deep scours and shoal formations in the vicinity of the weir both on the upstream and the downstream is minimized as far as possible fl To evolve the operation of gates to exclude maximum silt/debris deposits on the upstream side and also to minimize the entry of same in canals/channeis h) A relatively high intensity of flow is avoided in the deep scour zones, if formed i) If a shoal has formed on either on the up-stream, or on the downstream or both of the weir, it is washed out and kept away from the barrage as far as practicable j) The canal gate operation schedule should also consider constraints regarding rates of lowering / raising the water levels in the canal It should also consider the safe rate of filling of the canals The operation and regulation can be divided into three distinct periods as given below 6.1.7 Pre-Rainy Season Operation It is a low flow period and normally no wastages of water shall be permitted during this period The barrage gates/falling shutters shall be regulated such that all the available supplies are conserved and pond level is maintained Any excess flow over and above the requirements tnrough the head regulator(s) shall be released through under-sluice bays and silt excluder tunnels, wherever provided The release througn the head regulator of the canal snail be based on the discharge tables The discharge tables shall be occasionally cnecked for accuracy by actual measurements in the cana1 WWDSE Addis Ababa in Association with -65- Detail Design of Eale Gaduia irrigation & Drainage P'o/ecfMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual For any flashy flood, the canal may have to be closed temporarily, if the concentration of suspended silt is in excess of the safe limit prescribed The discharge tables shall be occasionally checked for accuracy by actual measurements in the canal 6 1.7 1 Rainy Season Operation Gauges to indicate flood stage shall be installed sufficiently (not less than 1000 mj upstream of the barrage at suitable locations so asto ensure adequate margin of time for operation of gates at the weir/ barrage site. a) During low floods, the gauges snallbe signaled and recorded every three hours while in medium and high floods: these shall be recorded every hour The signaler at the head works, on receiving the flood warning shall communicate the same to the official/officer-m-charge of the head works and other regulation points downstream and to the distnct officers of the neighboring distncts b) The advisability of installation of wireless transmitting stations of head-works on major rivers for speedy transmission of flood warning should be considered) c) In order to create most favorable conditions for sediment exclusion from the canal still-pond regulation should be resorted to as far as possible However in locations where canals cannot be closed for flushing, semi-still pond/regulation may be adopted (as in the case of power channels ) as given below a) Still pond operation In still pond operation, all tne gates of the under-sluice bays are to be kept closed so as to limit the discharge flowing into the pocket to be equal to the canal supply The specified or required discharge only should be drawn in the canal and the surplus river discharge should be passed through the spillway bays or river sluice bays, if provided As the under-sluice bays are kept closed, the low velocity in the pocket causes the sediment to settle down and relatively clear water enters the canal. However, the pocket gets silted up in this process after some time. At that time, the canal head regulator gates snouid be closed and deposited silt should be flushed out be opening the gates of the under-sluice bays. The canal supply may be stopped during this scouring operation which may take about 24 hours After the silt deposits are flushed out sufficiently, tne head regulator gates should be opened and under-sluice closed This operation is desirable where the crest of the head regulator is at a sufficiently higher level than that of the upstream floor of the under-siuice bays This still pond operation snouid be continued till the river stage reaches the pond level after which the under-sluice gates should be opened to avoid overtopping b) Semi-still Pond Operation WWDSE Addis Ababa in Association with -66- Detail Design of Bale Gadula Irrigation & Drainage Project iCT Pvt Ltd and ABCE PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1 Volume - VII Operation and Maintenance Manual In the semi-still pond operation, the gates of the canal head regulator are not closed for flushing of silt deposit in the pocket. The gates of the under sluice bays should be kept partially open to the minimum necessary so that the bed material in the pocket could be passed downstream. The discharge in excess of the canal requirement should be passed through the under sluice bays During rainy season months, it is important to keep a constant watch over the sediment entering the head, the portion thereof ejected by the extractor if any and the sediment deposition taking place in the canal and to ensure that sediment deposition only to the extent that can be washed out early in the cold weather before the full demand develops, is allowed For this the following actions shall be taken a) Sediment charge observations (both suspended sediment and bed load) shall be made at least once a week/ fortnightly/ month (as per necessity) in low floods immediately below the head regulator, below the silt ejector, if any. and at any other sensitive point lower down the canal The frequency of observations may be decreased in medium and high floods b) Cross section of the canal shall be taken occasionally at a few sensitive points to watch the extent of sediment deposition of the canal, particularly before and in the rainy season c) Water surface slopes in the sensitive head reach of the canal shall be kept under observation daily with the help of gauges, 1) When the sediment charge exceeds beyond a specified sediment cnarge during medium/high flood and re-opened when the sediment charge drops below tne specified limit. Since the silt carrying capacity of the canal would govern this specified limit, it would vary from project to project and should be estimated based on actual data/ experience In so far as the power channels are concerned, this would depend on the size of the panicle carnea down. 2) When sediment deposition at the sensitive points has reached the maximum permissible bed level This limit along with the sediment charge in excess of which the canal is to be kept closed, may have to be fixed for different months during the monsoon penod in order to be able to meet the irrigation and power demand. Since cross flows and vonex formations dangerously cause deep scours both on the upstream and downstream of the barrage leading to washing away or sinking of cement concrete blocks and loose stone aprons, ana damages to the nose and shanKs of guide bunds, visual observations of the direction of current and vortex formation during low and medium floods should he made After critically observing the effects of different Datterns of gate operation on the same the engmeer-in-charge should judiciously select the correct pattern which would cause only minimum scour or minimum shoaling 4W9SE Aadis Aoaoa in Association ivifh -67- . ' ' -’I > ■ • -3CE =>L0 Detail Design of Bale Gadula Irrigation & Drainage Project Detune'Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual The engineer-in-charge should remain conversant with shoal formations, changing network of spill channels, etc., which cause unequal distribution of flows through different bays, cross flow near the barrage floor ends, vortex formations, etc He should try to wash away the shoal formations coming too close to the barrage/weir and otherwise improve flow conditions at the work by judicious gate operation The pond ievel shall be kept minimum required to feed the canal with the required discharge by suitably opening the gates It shall be ensured that in a high flood, all falling shutters of weirs are lowered and all gates raised clear of the water level with adequate freeboard to clear floating debris. It would be desirable to constitute a gate regulation committee comprising senior engineers of the project design office and research station and engineer-m- charge of the head works Division. The committee should hold meetings at least once during pre-rainy season rainy season, ^preferably twice) and after monsoon and should review the gate operation pattern and modify wherever necessary on the basis of the observed river cross section on the upstream and downstream of the structure After some years when satisfactory flow conditions are established, all the recommendations of the committee from time to time should be compiled in the form of a manual so that guidance could be obtained by the gate operating personnel for future use in the project Generally with the rise in the flood discnarge a step-by-step gate operation with gradual increase of opening from ends towards the centre is sometimes recommended. In order to Keep a close watch on tne river behavior and bed configuration both upstream ana downstream of tne barrage river surveys should be conducted regularly once Defore the floods ana another after the floods The survey shall be conauctea over an area ciose to tne barrage for a distance of 2000 m both on the upstream and downstream The oea levels shall be determined by use of echo- sounders at close intervals of 10 m. depending upon the bed configuration, the pattern of gate regulation shall be modified suitably to ensure safety and better hydraulic performance of the barrage. Where floating debris try to enter the irrigation canai head regulators, trash booms may be erected just upstream of the head regulators. 6 17 2 Post Rainy Season Operation Sediment charge observations and cross section of sensitive points on the canal shall be continued at less frequent intervals till satisfactory conditions have been established. Still/semi-still pond operation, with sediment excluders/ejectors operating, depending on the surplus water availability should be continued till water becomes reasonably clear When a canal is first opened a low supply shall be run for a few hours at least and tne aeptn snould oe gradually raised according to the requirements The rate of filling and lowering of tne canal should be prescribed and these should not be transgressed Sudden ciosers should also be avoided A reasonable rate WWDSE Addis Ababa in Association with -68- Detail Design of Bale Gaoula irrigation & Drainage Project •CT Pvt Ltd and A3CE PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I Volume - VII Operation and Maintenance Manual depending upon the depth of the canal should be adopted So that there is slippage of banks by saturation during filling and back water pressures during emptying/ closer If a study of the survey data indicates that shoal formation has occurred on the upstream and/or downstream of the barrage in spite of judicial operation of the gates, during normal and flushing operation of reservoir, the shoal shall be removed by dredging by the use of suitable dredgers to the extent possible so that satisfactory flow conditions are established and also desired capacity is restored 6.1.8 Study of Imageries Landsat imageries obtainable from the National Remote Sensing Agency may be helpful in the studies on vanations of the bank lines, flow patterns, etc, taking place from year to year both on the upstream approach and downstream exit of the weir Regular studies with land sat imagenes may be made and remedial measures for improving the river behavior and flow pattern may be taken up immediately if the studies so warrant. Wherever erosion or damage to the protective works on the upstream and downstream banks close to the barrage are observed these should be immediately repaired before the onset of the next monsoon 6.1.9 History of Head works A continuous history of river benavior and the overall performance of the oarrage/weir nead regulators and river training works should be maintained on all major head-works The history should include details of repairs earned out and river training measures adopted and tneir efficacy. It should also contain details of the gate/shutter operation pattern adopted from time to time. Necessary drawings should be appended in the history Pre-rainy season and post rainy season river bee contours may be plotted, reduced in size and properly filed in serial order for comparison to understand the pattern of shoals scours, oblique flow. etc. 6.1.10 List of Referred Indian Standards IS No. 958:1981Specification for ready mixed paint, brushing, bituminous black, lead free acid, alkali and heat resisting IS 289:1963 Specification for aluminum paste for paints {revised) IS 2932:1974 Specification for enamel, synthetic, extenor (a) undercoating, (b) finishing (first revision) IS 3973:1984 Code of practice for the selection, installation and maintenance of wire ropes (first revision) IS 4890 1968 Methods for measurement of suspended sediment in open cnannels IS 6532 1972 Code of Dractice for design, installation, observation and maintenance of uplift pressure pipes for hydraulic structures on permeable foundations WWDSE Adois Ah.wa in Association with -69- Detail Design of Balp Gaouia Irrigation & Drainage Project :Cr Dvt id mi _ • . Octane1 2C11Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual IS 6646:1972 Specification for oil of turpentine, solvent grade IS 7718 Pt3 1975 Recommendations for inspection, testing and maintenance of fixed wheel and slide gates Part 3 after erection 6.2 Maintenance of Guide Bunds (There are no guide bunds but the road along the main canals acts as guide bund therefore it may be inspected and maintained manually). The afflux bunds, guide bunds shall be examined in the dry/ cold weather ana necessary repairs to the bunds, pitching and aprons earned out and completed well before the onset of monsoon. An adequate stock of boulder/stones shall be maintained close to the protection works for use in emergency 6.2.1 General Complete drawings of guide banks are to be maintained as permanent records for ready reference. The completion drawings should indicate the details of work actually executed Pre rainy season and post flood inspection of guide banks are to be carried out regularly to ascertain the health of the structure and repairing works, if any, to be done for safety of the guide banks. Pre Rainy season and Post rainy season surveys should be carried out regularly Dy taking section along centre line of the embankment crest and by taking cross sections at every 30 m Along pitched guide bank, plotted to a fixed scale and on the same sheet in different distinguishing colors to visually bnng out the health of the structure before and after rainy season At the zones where flowing channel of tne river is adjacent to banks, cross sections should cover the complete width of deep channel or apron width wmchever is more 6.2.2 Maintenance during floods Top of bank should be kept clean from bushes, jungles, high grass, etc. so that inspection ana the carrying of the materials for maintenance during the flood may be possible without any hindrance A register should be maintained to record the health of the structure, angle of attack, damage caused and if any action to be taxen during the floods or after flooas. Some permanent gauge should be established close to the structure, say an abutment ana another well gauge in the back fill of the abutment and daily records of levels are to be maintained during the flood season. Occasional patrolling of guide banks should be done to monitor tne behavior of the structure and to take protective action where abnormal swirls, eddies or scour is apprehended if severe scour hole is observed at any location, remedial measure are to be taken Dy dumping loose boulders, boulders in wire netting or cement concrete blocks so that the toe of tne embankment is protected from the scouring action In first year Patrolling nas to be invariably gone WWDSE. Adtiis Ababa in Association with -70- Detail Design of Bale Gadula Irrigation & Drainage Project ICT Pvt ^td and ABCE LC n October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual If the erosion is noticed at any reach, boulders in wire crates may be dumped or launched at the site to reach to the maximum scour depth so as to stop further scouring and the country side of the embankment may be strengthened and widened by sand filled bags Stone pitching on river side slope scooped out and swept by swirling current should be immediately be replaced by stone boulders underlain by the inverted filter For repair works of such emergent nature, adequate stock of boulders should be available at suitable places to meet any exigency. 6.2.3 Maintenance after Floods The health register of the structure should be seen and action taken against each item should be recorded. Even if after examination it is found that no action is required, the reason for taking such a decision also should be recorded Annual inspection of all underwater protection works should be carried out by the Engineer-in-charge of works after flood season. Soundings and probing n the upstream apron and in the area upstream of it and in the downstream apron and area downstream of it should be taken to assess scour and launching of the aprons in the vicinity of the structures Any short fall/damage should be made good before the next season Surveys as mentioned in 1 1 3 should be carried out meticulously for a detailed analysis of the behavior of the structure and assessment of remedial measure necessary to restore the structure The original aesign of the structure may be penodically reviewed for the actually observed discharge in the river and the benavior of the structure. Protection of banks, wherever required should be taken up and completed before the next rainy season Approach roads to the guide banks should be maintained in good condition for smooth and speedy flow of vehicles carrying materials for protective works including emergent works dunng flood season Communication facilities ana adequate warning system like wireless/telephone / internet should be adequately orovidea VWyDSE Addis ADaDa in Association with lC” -’vf Lta AB ?£ -Y Dera'/ Design of Bale Gadula Irnoahon & Drainage Project Octon?' 20'1Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - /. Volume - VII Operation and Maintenance Manual 7. MAINTENANCE OF HYDRO-MECHANICAL INSTALLATIONS 7.1 General All machinery at the works should be kept clean, tidy and in proper working order and care should be taken to ensure that it is properly handled in conformity with the manufactures’ instructions The mam mechanical items are generally the gates and tne winches. 7.2 Operation of Gates All lift gates should be operated at suitable intervals to free the mechanisu. and wash out extraneous material. In low supplies wnen openings are not desirable, raising of the gates by 150 mm for a few minutes should suffice If the gates have not been moved for a sufficiently long time, they should not be forcibly raised all at once but should be lifted by about 30 mm or so and left at that position for about 10 to 15 minutes till the silt deposited against the gates gets softened and water begins to ooze out. This is essential to avoid heavy strain on the machinery The speed of operation of the gates should be limitea to the maximum speed indicated by tne manufacturer The operation shall be so done that the safety of the structure is not jeopardized at any time and the permissible difference in static nead on either side of the divide walls is not exceeded beyond the safe limit, which shall be clearly specified. 7.3 Maintenance of Gates All cavities and angles in the gates/snutters snould be Kept clear of debris driftwood moss and silt accumulations. All drainage hoies in the webs of honzontal structural members should be Kept open and no water allowed remaining entrapped. Green stains should not be allowed to form on the steel members at the back of the gates/shutters. The gates and counter balanced boxes snould hang perfectly level and in plumb This should be checked occasionally and adjustment made as needed In case of shutters, the chams/anchors holding tnem should be kept free from rust. No painting is required for machined surfaces and surfaces of stainless steei brass or bronze These surfaces snail be protected by a coating of gasoline - soluble rust preventive non-corrosive compound The upstream face of the skin piate which comes in contact with water should preferably be painted with a suitable primer and subsequently with high quality long life in water for a long life The other parts of the gates/shutters which do not come in contact with water should be painted with paint conforming to IS 158 1981 or chlorinated rubber based paint or epoxy coal tar paint (cold application) The upstream face may also oe painted with any of these paints These paints may be substituted with decorative pamt (synthetic enamel) (see IS 2932 1974) for better appearance WWDSE Addis Ababa in Association with -72- Detail Design of Bale Gadula Irngation & Drainage Project ICT Dvt Ltd and aBCE PLC October 20HMinistry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I, Volume - VII Operation and Maintenance Manual 2 embedded in the wet second priming coat and do not puncture the first coat Drying time shall be at least 24 hours Sand spraying is omitted in the case of surface on the downstream side not coming in contact with water d) Finish Coat This is prepared by mixing 1 kg of aluminum pigment paste with 4 5 liters of phenolic resin maxing varnish. The first coat shall be applied by spraying at a coverage rate of approximate^ 7 m2/l The second finish coat shall be applied not earlier than h 24 h after the completion of the first finishing coat at coverage of The application procedure for sanded aluminum paint on new work shall be as detailed below a) Cleaning 1) Weld spatter or other surface irregularity shall be removed by any suitable means 2) Oil, grease or dirt, if any, shall be removed from the surface by the use of solvents, that is, clean mineral spirits, naptha or white gasoline; 3) S No (1) and (2) above shall be followed by sand blasting for removal of rust or mill scale, to present a uniform bright base metal. Any dust or grit remaining from this cleaning operation should be completely removed from the surface by brushing or with dry air, and 4) Painting shall be immediately commenced after cleaning in accordance with SI No (3) above bj First Primer Coat The first pnmer coat should be prepared by mixing 1 kg of aluminum past (see IS 289 1963). 4 5 liters of zinc chromate mixing paint and thinning it suitably with oil of turpentine (see IS 6646 1972) This shall be applied by brushing at a coverage rate of 10 to 12.5 m2 Drying time shall be at least 18 h unless otherwise specified oy the paint manufacturer C) Second Primer Coat The paint shall be prepared in a similar manner as in (b) except that no thinner shall be addea The paint shall be applied oy brushing at a rate of approximately 7.25 m211 Immediately after the application of the second coat, clean and dry sand with rounded grains of 30-50 mesn size shall be sprayed with low air pressure of 35.000 to 70.000 Pa (0 35 to 0 7 kg/cm ) so that the sand grains get 2 approximately? 25 m /l. This may be substituted by coal tar paint or decorative paint in case of downstream side The equipment shall be kept idle for 5 days after this treatment before it is put into service The application procedure for bituminous black paint shall be as detailed oeiow i he surface cleaning should be done as for sanded aluminum paint' detailea in 12 3 3 i ^a) Tne paint is tnen appliea cola with Drushes in 43 or 5 coats to obtain »--------------------------------------------------------------- WWDSE Addis Aoaba m Association with 'CT Pvt Ltd and ABCE PLC -73- Detail Design of Bale Gaouia irngation & Drainage Project October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual a desirable thickness of 0.45 mm Each coat should be allowed to dry thoroughly before applying the succeeding coat. The minimum drying time is 24 even under fh favorable conditions 7.3.1 Gate Grooves and Seals Grooves and particularly their machined faces should be kept clean and lubricated well and all sticky deposits should be scraped off before application of lubricant 7.3.2 Seals Efficiency of rubber seals should be tested initially after construction and at time of closures or isolation of different portions for repairs. The honzontal and verticality of the seal seta and wall plates shall be checked with spirit level and seal faces of tne rubber seal should be tested to press uniformly both by light test and by use of paper stnp inserts Seals of the gate should be checked for wear and tear and deterioration. These should be checked fcr wear and tear and deterioration These should be adjusted/rep laced as necessary Few sets of spare seals should be tested to press uniformly both by light test and by use of paper stnp inserts. Seals of the gate should be checked for wear and tear and deterioration. These should be adjusted/rep laced as necessary Few sets of spare seals should be kept in stock and stored for emergency in such a way that these seals do not get damaged/ withered with the passage of time while in stores. 7.3.3 Staunching Pipes Staunching pipes, where provided, should oe checked for their sealing efficiency and necessary repairs/replacements earned out 7.3.4 Steel Wire Ropes All steel wire ropes must be cleaned to remove all dust accumulation and lubricated with suitable greases at least once a year. The portion of steel wire rope which is submerged in water snould be lubricated frequently preferably thrice a year The clamps shall also be inspected 7.3.5 Roller Trains and Fixed Rollers The roller trains should be examined at least once a year Partially jammed rollers should be cleanea, freed and greased but totally jammed rollers should be replaced. The bolts of roller guard should be checked and tightened. The sliding/fixed rollers snould be extracted at the time of closure (unless necessitated otherwise due to some defects whicn may need immediate repairs) and cleaned and greased properly Worn out pins should be replaced and suitably held against rotation by filling the empty space between the pin and the side plates tnrough welding or by other approved means Spare rollers should be kept in stores for ready replacement. WV/DSE Addis Ababa in Association witfT -74- ICT Pvt Ltd andABCEPLC Detail Design of Bate Gaduia imgarion & Drainage Project October 201 ?Ministry of Water and Energy - Feoeral Democratic Republic of Ethiopia 7.3.6 Winches/Hoist Section -1, Volume - VII Operation and Maintenance Manual All winches and lifting drums should be examined at least once a year to see if all the gears and axles are clean and properly lubncated All grease-fed beanngs should be cleaned, old grease removed with kerosene oil and fresh grease applied The alignment of shafts should be checked and coupling bolts tightened All grease cups must be kept full of lubricants and covers tightened periodically to ensure lubricant moving and causing an effective seal against dust getting into the bearings. For winches with ratios of 60:1 to 100 1, four men should be able to operate the hoist easily If the working of any winch becomes hard and it requires more men to operate it, it should be examined and the defect removed before it is used Winch ear covers should have felt or rubber washers to check the entry of dust The winches should be operated in correct direction and to ensure this, direction or operation should be correctly marked and the limits of operation indicated 7.3.7 Issue of Certificate The engineer-in-charge should test all lift gated, and chain and clips of falling shutters and submit a certificate to the competent authority (as laid down in regulation orders) before the advent of the monsoon that all gates/falling shutters are in good operation condition 7.4 Lighting All flood lighting ana barrage illumination should be checked daily dunng flood season and once <n a week during slack season 7.5 Painting The painting of supper structures should be done once in two / three years 7.6 Hoists IS 10096 (Part l/Sec 2) 1986 may also be referred for inspection/maintenance of hoists considering the type of hoist provided on the barrages/ weirs before the onset of monsoon and after passing the floods WWDSE Aodis Aoaba in Association with -75- lCT pvr Lto and A3CE PLC Detail Design of Bate Gadula Irrigation & Drainage Project jctob^' 2C■ *Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 8. MAINTAINANCE OF CANAL AND DRAINAGE SYSTEM 8.1 Maintenance of Canal System The chief requirements of uniform canal are as follows. a) A clean regular bed, b) Straight clean slopes, c) Uniform berm widths, and Section - /, Volume - VII Operation and Maintenance Manual d) Uniform regular top width and outer and inner faces of both banks. Closure on main canal and branches shall be notified sufficiently in advance Whenever a canal is closed it should be inspected as soon as possible. All pipes and openings in the crest of falls shall be opened so as to drain off the water upstream of the fall. The canal shall be cleaned before it is run again. All masonry work shall be penodically cleared of rubbish, stones, bnckbats, etc., as the opportunity offers, especially the siphons and the stilling basins 8.2 Bed and Berm Bed and berm shall be scraped, where necessary and especially in tail reaches. Berm and bed lines shall be correctly aligned before scraping Berm shall not be scraped if it has not silted property Before starting work on either the bed or berms, they shall be aligned by flags and string. The former are necessary for the alignment in general and the latter to correct small irregularities in that. Every opportunity shall be taken to straighten the canal and to get rid of kinks and irregularities in the alignment and also to ease of all curves where scouring or silting takes place. Clearing operation shall be started from downstream to upstream starting either from the tail or a fall 8.2.1 Bed All grass shall be scraped and weeds removed from the silted bed wherever they are found to exist since their presence induces silt deposit. All local accumulations or continuous deposits or mounds of silt shall be removed to correct bed level. Beds shall oe leveled and their gradients regularized by the removal of silt mounds and all mounds higher than correct bed level. Bed levels shall be fixed correctly atclose intervals by means of sounding rods In case of main canals, \ branches and distributaries, silt at the junction of bed and slopes should not be removed if the section of waterway is not unduly affected. Small minors and all rail reaches shall, however, be cleared to the correct trapezoidal section The practice of cutting the silt aeposited at the junction of side slope and bed and throwing It on the bed to level it snail not be permitted WWDSE Addis Ababa in Association with -76- Detail Design of Bale Gadula Imgation & Drainage Proiect ICT Pvt Ltd and ABCE PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual NOTE-lt will be desirable to prepare a longitudinal section of primary canals during closure once a year Cross-sections should be taken in reaches where the section is over-wide or too much scoured. The behavior of canal should be studied and longitudinal section readjusted, if required Closure register should be maintained in which brief inspection report for each work along with details of repairs if any carried out shall be entered by the Engineer In charge. 8.2.2 Escapes Escapes shall be kept clear of silt and vegetation growth. These shall be run occasionally to test their discharging capacity and to maintain right of escaping excess water into natural drains in which such escapes join and to avoid tendency of cultivators to sow in low lying lands in the bed and along the sides of such natural drains. 8.2.3 Berm Berm cutting shall not be started until sample profiles have been cut and the lines carefully laid Where earth is required for repair of banks, berm pockets may be made in the manner specified in 4 1(c) Irregular protruding and overhanging berms shall be cut back to proper alignment and slope. If this is neglected berms fall in or protrude abnormally and the canal tends to adopt an irregular section or winding course Wherever berms have grown excessively thereby tightening the waterway they shall be cut to proper section. Berms shall be kept straight by trimming projections after aligning them correctly Heavy berm cutting may be avoided by regular trimming and scraping as the situation calls for every year. 8.2.4 Sift Clearance If a canal is in regime and taking its full supply, it is not necessary to clear silt to the theoretical cross-section. If the canal is not functioning properly, it may be sufficient merely to clear a portion of silt to get it into efficient working order or it may be necessary to clear to full theoretical cross-section on runoff the river canals and specially those which are also run for paddy irrigation silt is likely to deposit in distributaries and minors which may get picked up when clear water runs in the channel after monsoon. Longitudinal sections of silted bed of such channels should be taken during closure immediately after monsoons and the gradient at which silt should not be cleared below falls but if outlets in such places are overdrawing water due to rise in water surface, they should be raised Boning rods should be used to see whether the silt has been properly cleared As soon as a canal is closed for a fairly long period the bed bars shall be uncovered and the depth of silt over them recorded 8.2.5 Discharge Measurements Discharge observations on main canal and branches shall be cameo out at least once a month during non-monsoons During monsoons discharges should be ____________________________ *_______________ ____________ _________________________________ WWDSE Addis Anaoa in Association with -77- Detail Design of Bale Gadula Irrigation & Drainage Protect .CT Pvt Ltd and ABCE PLC-------------------------------------------------------------------------------------------------------------- ,Ministry of Water and Energy - Federal Democratic RepuDlic of Ethiopia Section - /, Volume - VII Operation and Maintenance Manual observed more frequently for diversion canals. Percentage to normal discharge should be revised from time to time for purposes of regulation and distribution of water In case of high seepage losses in the main canal, discharge observations should be the seepage loss is high and suitable remedial measures should be taken to reduce it Current meters should be used for observation of discharges. Where such facility is not available or where depth of water in the channel is insufficient, floats may be used Discharge sites should be fixed at suitable points and may preferably be in the form of flumes, falls or straight runs of lined section All discharge observations should conform to relevant Indian Standards Gauges at the head and tail of all the channels and at important points in between on long channels should be observed and recorded daily 8.2.6 Banks Banks shall be brought up and maintained to full section. The minimum width and free board of the bank shall be in accordance with the relevant Indian Standard Before continuous bank repairs are started profiles shall be made at about 100m apart. These shall be at the correct height and width of the bank repaired and shall be cnecked before work is started All noies ana rain cuts snail be fully opened up to the bottom by digging steps not more than 0 5m deep in tne sides and removing all the fallen or loose lumps of earth, bushes, grass roots etc Filling and repairing shall be done by placing level layers of earth (not more than 15cm deep) obtained from source specified in the geological report of the project The earth in each layer should be free from clods, roots, grass brickbats and other debris and it shall be compacted at adequate moisture content. Leaks should be stopped from the upstream side by cutting off the penetrating water If practicable cracks should have good earth worked into them by chisel pointed poles, but if the presence of water against the bank prevents this, the leakage should be stopped by a cover of good earth thrown over it. Subsequently, in dry season the defective part should be opened up and properly remade Top of bank shall be smooth and free from clods and silt mounds. They shall be given a slight outward cross siope of about 1 in 80 in order to take the rain water away from the canal. Both edges of banks especially the inner ones shall be neatly aligned parallel to the canal They shall be absolutely straight in straight reacnes and regular on curves Both inner ana outer slopes and toes of banks shall be free from irregularities Only projections shall be cut down and earth thus obtained should be utilized in filling hollows WWDSE. Addis Ababa in Association with -78- Detail Design of Bale Gadula Irrigation & Drainage Project ICT Pvt Ltd and ABCE PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I, Volume - VII Operation and Maintenance Manual Loose earth shall not be left lying on top of a bank Wherever filling is necessary it shall be well compacted Grass or turfing shall not be scraped It should only be cut as far as necessary to show the surface of the bank and to avoid the holes being hidden under long grass. Scraping the top edges of banks for appearance shall not be permitted Earth from any surface for bank repairs shall be placed where required and in such quantities only as needed, otherwise banks will become irregular by developing unwanted bulges and hollows The top of both banks shall always be kept smooth and free from holes. One bank, at least, should be maintained as an inspection bank. Banks that are too low should be raised to the proper design levels as early as possible In pervious reaches where seepage is excessive puddle clay core, in place of sand core, may be provided Where water logging is observed seepage drains shall be provided on either bank. 8.2.7 Sources of Earth for Repair Suitable earth for repairs may be obtained from the following sources a) From Internal clearances material obtained from internal clearances shall be utilized b) By Removal of Irregularities - High banks can be lowered and bumps or projections on top or sides cut down to fill in the hollows c) From Spoil Banks d) From Prominent Mounds in the fields Near the Site e) From Beds of Drams Near the site The following precautions shali be observed in taking earth from out-side borrow pits. a) No borrow pits shall be dug within 6m from the toe of banks or driving road or ramps of bridges. b) Borrow pits shall normally be not more than 30 cm deep, and c) Earth shall not be taken from the toe of banks, as the natural rounding of the corner should not be disturbed as shown in Fig 1 8.2.8 Roads and Ramps Roads and ramps snail oe kept smooth and shall have a regular longitudinal grade Ramps and approaches to bridges should be maintained smooth and to the designed gradient Where there are spoil banks on tne side of the roadway and hiqher than it, there shall always be a continuous dram along the outer edge o. the road as well as cross drains tnrougn the spoil banks the latter being at right angles to the former and leading with a gentle slope to the boundary ditcn vWVDSE Add/s Adaoa tn Association with ,CT pvr -to and AB DE PLC '' 9- Derail Design of Bale Gaduia Irrigation & Drainage Project October 201 ’Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1, Volume - VII Operation and Maintenance Manual Cross drains shall not be allowed to get higher than side drains. Where there are no spoil banks outside the roadway no drain is required. Where the service road has a longitudinal gradient such as near bndges, side drain along dowel (earth in parapet) should be provided The roadway shall be never allowed to remain blocked by fallen trees or in a dangerous condition by holes and hollows. Kilometer stones shall be adjusted to the correct position, white washed and lettering re-colored, when necessary Guard stones and bumping stones should De adjusted and white-washed While undertaking any repair work on service road suitable diversion shall be provided to allow uninterrupted traffic during repairs A dowel snail be made to the size and shape specified in the drawings. Ordinary repairs to canal roadway should be taken in hand after first heavy rain falls ano should never be postponed till the end of the monsoon. The canal roadway should be inspected after neavy rain and holes where seen snail be filled in accordance with 3.3. Silt from canal berm may be used for closing these holes wnere there are no spoil banks Holes generally result from defective drainage which should be looked into and remedied otherwise the holes will quickly re-open 8.2.9 Vegetation Growth All vegetative growtn on canals, distributaries and minors should be cleared from toe to toe of the outer slopes of the Danks Shrubs, 'arge grass such, small trees should De dug out Dy roots Stumps of trees that have been standing should De cut down to at least beiow the ground. Ant hills shall be dug out and leveled off Ail vegetative growth on escapes and drains should be cleared from the outer edge of the inspection Dank to the inner eoge of the opposite bank The surroundings of chainage stones should be kept clear of jungle, grass or any other rubbish to enable them to be seen from a distance To save maintenance money and enhance income, grass can be auctioned after 10 days of the first rains of the rainy season and many cut may be permitted LaDor only with pnoto identity cards should be permitted within the premises. All vegetative growth on escapes and drains should be cleared from the outer edge of the inspection bank to the inner edge of the opposite bank. The surroundings of chainage stones snould be kept ciear of jungle, grass or any other rubbish to enable them to be seen from a distance WWDSE Addis Ababa in Association with -80- Detail Design of Bale Gaduia Irrigation & Drainage Project iCT Pvf utd. and ABCE PLC October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 8.3 Drains Maintenance Section - / l plume - VII Operation and Maintenance Manual Details of all the drams suer as to discharge and dimensions are given in Appendix II All t.ne drains are beiow ground level for easy flow of drainage water 8.3.1 Structures on Drams There are canal falls in tne drains and these structures shall be inspected and proper maintenance shall be piannea and executed accordingly The inspection bank should be maintained in good condition Silt cleared from the bed of a drain should be used to fill up noles and ruts on the inspection path / raise the canal banks/ service roads This silt should not be thrown up in drains Trees should not be allowed to grow on the inner slopes of drains The dead branches and rubbish that may have accumulated in the drains should be cleared before the monsoon breaks Buncs snouid not De permitted .n drains and should De removed if found existing □efore nc~soor creaks r ---~ recoraea r a register 8.4 Plantation ~ ' “cse~'ed -ar at suitable points and Acquired iand widtn of canai snouid De demarcated oy planting suitable species of trees at suitable intervals Sowing seed or plantation snouid commence in June anc De fimsned by tne middle of the montn so as to get the full benefit of the rams in tow ground iiaoie to flooding seeds reclining sideways Where necessary a Drop snouid be sown on ridges The roots of seedlings should not be cut nor oroken wnen transplanting They should be dug out with a good ball of earth adhering and so carried to tne new site If grown in pots like eucalyptus, the roots are sure to be pot-oouna In sucn cases the pot should be earned to the new site and the seedling roots bare of earth and straightened down into the noles dug for them This greatly facilitates tneir subsequent growth The parasitic plants sucn as AMARBEL ana BA-NDA should be removed. carried to an open space and burnt if the tree is completely covered by the parasite it is recommended to cut it down ana burn the parasitic plant at once All large roots found in the plantations should be taken out during the rains and burnt into charcoal when ary All newly planted trees and also those which are less than 2 m in neignt should De oroperiy protectea oy suitaDle tree guards The old tree guards snouid oe repaired properly where necessary and all grass should be weeded out Newiv planted trees snouid be watered regularly but not in excess ana me top soil toosenec >cor after watering Estaonsned plants wmeh have only beer less man *. ? ear .hougn net so OT*en ad line require to be given similar treatment cVWPSE Addis Aoaoa in Association • " ?? Detail Design if Bak 3aduia Irrigation & Drainage Pr >/ecf O •». rpr * •Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 8.5 Maintenance of Lined Portions of Canals Section - /. Volume - VII Operation and Maintenance Manual Incase of Bale-Gadula lining has been provided in Main Canals (MC-1 and MC- 2; ana in all secondary canals (13 in number 5 in the left bank and 8 in the right bank) from the considerations of the seepage and steep slope A lined canal should be maintained so that it continues to function efficiently and serves the purpose, for which it has been constructed, throughout its effective span of life. In addition to maintaining its imperviousness, the lining should be maintained so that it also continues to have the same discharge capacity for which it has been designed and which it nad when it started operating soon after the construction was over The reduction in discharge may generally be due to accumulation of silt; cracking \ of lining, failure of the drainage growth of weeds, algae and moss, seepage and evaporation etc 8.5.1 Efficient Working Normally no silt deposition should be permitted to take place in a lined canal Sometimes the canal may nave to be run at less than the designed full supply discharge on account of fluctuating water demands over the base periods of the crops to oe irrigated Also even for a single crop discharge requirements vary x rom montn to month Sucn low discharge conditions include deposition of silt over the canal bed owing to low velocities of flow Consequently the discharge carrying capacity or tne lined canal is adversely affected Silt deposition in linea canals can oe minimized by judicious operation of gates of cross regulators silt ejectors/aesilting basins wherever providea the maintenance. These gates snould be lowered for ponding on the jpstream side only under the following conditions 8.5.2 Inspections of Lining Whenever canal is closed for periodical inspection and repairs, the lining, its- auxmaries ana special design features should be carefully inspected The following points snould be noted while carrying out the inspection: a) Whether any cavities or pockets have been formed behind the lining At places where considered necessary these may be checked by sounding the lining tiles inspection of wet patches on outside slopes on regular basis should be done b) Development of any cracks or displacement or damage to lining, c) Silt deposits and weed growth, and d) Bench marks/Boundary pillars full supply water levels/gauge at suitable intervals De pointed/fixea to know about the hydraulic efficiency of the canal 8.5.3 Maintenance of Lining Tnere can De distress to tne lining ranging from small settlement cracks to excessive heaving displacement ana sinking of the lining in the following situations a) Cuts in soft fine grained soils especially when the lining was laid directly on WWDSE Addis Ababa in Association with -82 Detail Design of Bale Gadula irrigation & Drainage Project rp '' ^td and October 2011Ministry of Water ana Energy - Feaerai Democratic Republic ot Ethiopia Section - I Volume - V!l Operation and Maintenance Manual the soil without any special preparation of the sub grade b; Freshly laid embankments esoecialiy if composed of clayey soils, c) High continuous spoil banks, left too near the canal excavation without sufficiently wide berms and adequate arrangements for draining the rain water away from the canal. d) Cavities behind lining caused due to sucking out action on sub grade material by oscillating waves or fluctuating supplies of water of the canal through cracks, open joints and holes in lining, such action as may be necessary to avoid recurrence of any failure in the lining should be taken by investigating the causes of the failure and remedying them The defects or damaged parts of the lining joint I filler etc should be immediately attended to and repaired so as to ensure a sound, stable and watertight lining Any activities or pockets detected behind the lining should be carefully packed “ with sand or other suitable material Care should be taken to ensure that the lining does not get damaged or displaced dunng the operation Damageo or displaced portions of lining should oe removed and replaced by fresr lining of quality comoaraoie to *ne original lining The sub-grade should be thoroughly comoactea and orecared in accordance with IS 3873 1992 before a z r.g :re -resn mirg Tne -racks or.er man nair cracks; snouia oe filled witn Ditumen or otner suitaDle filler so as to ensure water-tightness of the lining A more effective sealing of cracks may be ootameo by cutting a V-groove along the race of tne cracks before filling witn sealing compound Minor cracks on the lining may be seaiea by dumping powdered clay upstream of the cracks The lining snouia oe protected from tne ingress of rain water behind the lining The free eage snouid be well tuckea into tne canal bank. Turfing of the slope aoove the lining level would greatly neip in preventing scours and gully formation 8.6 Carriage of Authorized Discharge Suitable measure should be taken to bring the canal to carry its authonzed discharge wnen it is noticed that the discharging capacity is reduced It should be done by maintaining the lined surface of the canal to its ongmal shape and slopes 8.7 Performance of Canal An accurate and systematic record of the performance of a canal should be maintained by periodic observations of Mannings roughness coefficient, evaporation ana seepage losses life ana benavior of the lining adopted surge wave heights ana performance of any special design features like pressure release system provision of humps or regulators etc 8 8 Maintenance of Embankments Proper maintenance of embankments is e*t emeiy important as breaches in tnem r can be disastrous ano may cause abater damage than the inundation by floods where no embankments a e oroviced The maintenance work may be r WWDSE Andis Abanam Association with -93 Detail Design of Bale Gaduia irrigation & Drainage Project Octone’ 2C*1Ministry of Water and Energy - Federal Democratic Republic of Ethiopia divided in two parts a i Pre rainy season maintenance b) Rainy season maintenance 8.9 Pre Rainy Season Maintenance Section - I. Volume - VII Operation and Maintenance Manual Existing embanxments have to be repaired or reconditioned to the original design section in advance for their efficient performance during the ensuing rainy season The free board may be checked up for any rise in bed level of the river or other constrictions which may result in h'gher design flood and provided/ maintained accordingly All hollows and depressions in the embankments section, wherever existing, snould be made up with rammed earth after clearing the site of loose earth and vegetal materials Where the top material is sandy or silty, it is desirable to provide a cover of soil containing 10 or 15 percent of clay well rammed or rolled. A register of leaks should be maintained indicating the location and action taken during the rainy period The ieaks which could not be fully treated during the rainy season should be attended to immediately afterwards Such leakage sites snould oe opened in full width of tne embankment taking care to trace to its uDS* eam ends and r then be refilled watered and rammed the old earth being steeped or oencneo cacK at sides ano new earthwork properly bonded and interlocked into the oid Rodents and otner animals make holes cavities and tunnels through and under embankments These are source of danger causing leakage and excessive seepages which may give rise to serious breaches during flood period Such holes snould be carefully located examined provided with an inverted filter filled with earth and rammed Alternatively such holes should be filled with well rammed stiff clay All the masonry works should be carefully inspected to detect if there is any danger of seepage of water along the planes of contact between the earth and masonry The earth adjacent to the masonry work should be laid in 15 cm layers watered and compacted brought to the design section For embankments which were severely tnreatened by erosion during the previous rainy season, revetment/nprap or other river training works should be separately examined In case of wave action, pitching may have to be provided 30 cm above the water level in flood Approach roads and aiso top of embankments wherever they are designed to carry vehicular traffic as well as ramps provided for inspection so far they serve tne purpose of transport of materials and inspections both during the pre rainy season and rainy season periods No habitation should be permitted on the embankments All departmental vehicles boats and launcnes should be kept operational WWDSE Addis Ababa in Association with ~ rc\t Ltd ind ABCE L . nr -84- Detail Design of Bale Gadula Irrigation & Drainage Pro/ect October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - I Volume - VII Operation ano Maintenance Manual All pumping equipment should be repaired and kept in readiness before onset of rainy season All sluice gates, valves be kept greased oiled and treated, if provided All tools and equipments including torch lights lamps spades etc and flood lighting articles as well as materials for erecting temporary sheds at the work sites for workers should be arranged and stored at suitable places Proper communication system should be installed before onset of the rainy season. 8.9.1 Maintenance during the Rainy Season During the rainy season prompt maintenance of the embankment is required as the flood water of river threatens the safety of the embankment mostly during this period. This is all the more important in case of new embankments and also in case of those reaches of old embankments where breaches occurred in the past The establishment required to be engaged for proper maintenance of an embankment will necessarily depend on the importance of the embankment and behavior of the river As tne river toucnes tne embankment and river shows rising trend round the : cck catroiiing snood star: oy sta’’ engaged for mis purpose and continue till water finally recedes During this period inspection of senior officers should be cameo out systematically and all the concerned staff and officers should remain alert to meet any emergent situation. Special vigilance is necessary in the countryside of the embankment to detect any doiI formation due to seepage This should be immediately attended to by providing loading perm to counterbalance exit gradient. A suitable filter material may be placed around the boil below the loading berm to arrest fines in seepage water To prevent the water from overtopping and washing out a portion of the dyke, a dowel of half sand-filled bags at the riverside at the top of the embankment may De provided Repair of ram suits in the embankments stacking of material and machinery required for repairing, putting the top embankment in order etc., should also be made Scouring and eroding behavior of the river should be carefully watched for taking necessary precautionary measures In this way by proper vigilance and timely action for repair works flood disaster can be reduced to a great extent All information connected with rising flood water level and flood situation should be passed on to The concerned higher authorities to enable them to take safety measures in time WWDSE Aodts Ababa in Association with ®5- • ufd n o ABCE PL O’ D'-' 20’:Ministry of Water and Energy - federal Democratic Republic of Ethiopia Section - I, Volume - VII Operation and Maintenance Manual 9. MAINTENANCE OF CANAL AND DRAINAGE STRUCTURES A list of all structures is given in section 2 2 Table 2.10 of this report All the drawings of all tne masonry structures are to be maintained in a bound volume and a register kept in site office for recording of remodeling or repairs, etc carried out from time to time and are marked in different colors on drawing and note to this effect is given so that the relevant case and document could be linked All masonry structures should be maintained through proper repairs in a sound condition Any damage noticed in these works should be speedily rectified Care snould be taken to ensure proper curing of repair work No grass should be allowed to grow near the parapets or wings of canal structure whicn should be Kept scrupulously neat and tidy Metalling over bridges and earthwork in both minor and major ramps should be complete and well consolidated everywhere Ramps for bridges over canal should be maintained in proper condition so as to ensure the canal bank is not encroacned jpon All drainage crossings downstream ot canal structure where significant canal erosion persists due to turbulence of the wave action dumped riprap consisting of gravei/smail oouiaers snouio De provided Protection by launching apron should be provided only in a lengtn so as-to cover maximum scour in a slope of 2 1 Dumping of boulders should not be above bed level Emoankments should be protecting by pitching on tne side slope witn stones Stones left out protruding in a staggered fashion will be neipfui in dissipation of energy However, if this provision does not improve tne situation tne cause should be investigated and suitable energy dissipating device provided downstream of the canal structures Scour charts snowing the depth ano extent of scour should De maintained for all major canal structures wnere this tendency persists The charts should be re plotted and revised at least once a year after the annual closure 9.1 Outlets All outlets snould oe regularly checked ano set right if found defective, in accordance with the detailed instructions issued by the department Outlet pipes should not be left lying aDout the canal They should be carried to the nearest inspection house as soon as cnange in outlet has taken place and pipes are found surplus They should be stacked neatly Water courses should have culverts/siphons wnerever needed and should be properly maintained to avoid wastage of water Register snould be maintained and head of water ( H ) of each outlet i e the difference between the water level in the canal and the centre line of the outlet at its exit end when the canal is running at full supply level should be measured every month It will be of great help for ensuring that the outlets draw their authorized share of canal water Tne outlets should be so fixed that these draw WWDStE Addis Ababa in Association with -96- r r Lf< jc-r r, - Detail Design of Bale Gaduia Imgation & Drainage Project October 20'1Ministry of Water ana Energy - federal Democratic Republic of Ethiopia Section -1 Volume - VII Operation and Maintenance Manual their proportionate discharge/silt when compared to the supply in the parent channel The working of the outlets can be evaluated from the register and these can be adjusted suitably during the month of April and October 9.2 Gates of Canals Mecnamcai gates should be oiled greased and Kept in perfect working order Exposed surfaces snould be kept property painted to prevent rusting and date of painting marked on them Exposed surfaces which have been recently painted should be periodically examined and any patches of rust found should be removed and surface painted. The lifting gear should be property lubricated to keep it in an easy operating condition and to prevent rusting and all lifting gears should be properly lubricated once a month Tne gates and their embedded parts should be inspected during closure They should be ecaired painted and lubricated wnerever necessary r Gates etc snould be periodically operated to the extent possible to see that tnese are in proper upkeep 9.3 Over growth of Grass and bushes (Jungle Clearance; Grass arc -ungie sncu.d not ce allowed to grow on the structures, it should be dug out by roots. Slime and Moss which often coat masonry structures should be carefully scarped off care being taken not to injure the mortar or plaster in doing so 9 4 Regulation No leakage snould oe permitted through the neaus of canals that nave been closed as a little water dribbling down a canal promotes tne growth of grass and weeds in tne bed When a canal is first opened after clearances a low supply should be run. for a few hours and tne gauge then gradually raised according to the requirements The gates at the cross regulators snould De towered only after the parent channel has Deen run for some time The lowering of gates should be to the extent necessary to create the designed pond level The downstream of the parent channel should not be kept dry with full pond level upstream of the regulator unless conditions require the same and tne structure is designed for it For regulating supplies into the distributaries the discharge through eacn bay should De more or less equal when number of bays is more than one Suitable silt / control measure should be introduced where excessive silt is likely to be drawn by a distributary Standing regulation orders for all important mam canals and branches and critical works mere on should be framed and observed to ensure safety of works and orooer utilization of water These regulation orders should be action oriented specifying tne duties of various categories of staff connected with me regulation Acrd r Associatior with -87 Detail Dei ir if Bale Gadula Irrigation A Dran tge *Ministry of Water and Energy • federal Democratic Republic of Ethiopia Section - I Volume - VII Operation and Maintenance Manual work and should be in possession of all the concerned staff looking after the maintenance No regulator should oe planked up higner tnan is necessary for regulation or kept planked up after me necessity no longer exists The staff-m-charge of a canal regulator or distnbutary head should always have written instructions about the gauges to be run, the maximum and minimum permissible being clearly stated therein A line marking tne full supply level should be painted on the upstream face of every structure If there is no structure in a considerably long reach, full supply level should be marked on the profile walls specially constructed for this purpose such that it is conveniently visible from the inspection bank 9.5 Cross Drainage Works 9.5.1 Inspection Regular inspections of cross drainage works on major rivers and drains are necessary every year before the floods to ascenain/examine their state of condition and after me floods to ascertain actual functioning and damage if any during me floods Certain inspections are to oe carried out during the canal closure All inspections shall be directed to the following aspects a) To see tnat the cross drainage ana appurtenant works are in good operating conditions and to make them operable if tney are not so b) To determine after the floods the repairs or remodeling measures required. cj To see if any leakage from the canal is taking place at vulnerable locations d) To investigate for presence of any unusual pnenomenon in respect of boils piping sweating of bank or saturation of substratum etc or cracks in the structure ej To check any changes in the design features in the field, and to restore it to the orginal design and to redesign the nydraulic structures after the floods, if so warranted, f) To study the behavior of pressure relief valves, weep-holes and filters if any installed in the ‘loors/retaining walls of cross drainage works g/ To study the water levels recorded and the quantum of flood discharge passed through the cross drainage work for evaluating its performance In case of excessive rise of levels, investigations have to be carried out and remedial action taken to improve the conditions if necessary also during canal closure If it is due to blocking of passage the works may have to be de-watered for inspection, and hl To study the longitudinal section of drainage to see whether aggradations and degradation are taking place endangering the safety of the structure In add.‘.on to me above tne inspection snail include investigation of the following aspects to guard against damages occurring to the cross drainage work WWDSE Addis Abate m Association with -88 Detail Desion ot Bale Gadula Imgation & Dramaae Protect <CTPv‘ Ltd Ocf^er 2'Q11Ministry of Water ano Energy - Feaeral Democratic Republic of Ethiopia Section - /. Volume - VII Operation and Maintenance Manual a) Investigate if any meandering of the drainage channel in the vicinity of the st ucture o cnanae of r r period flow pattern nas occurred during the previous monsoon dj Investigate wnetner new streams have Deen diverted into the main stream for which tne work has been constructed resulting in inadequate capacity of the cross drainage work. c) Investigate if any obstruction has been created in the drainage higher up or lower down and ascertain if such obstruction has affected the functioning of tne cross drainage structure d) investigate whether the tanks on the upstream of the structure are in good condition and ej Investigate tne construction of bridge or other structures, with less waterway, wnicn may increase the H F L as a result of afflux. Cross drainage works snail De inspected periodically the inspection shall be not less tnan twice every year at least once before monsoon and once immediately after monsoon In addition, wnenever a flood exceeding the design flood or the previous recorded nignest “oou passes tne cross drainage works the structure shall be inspected to studv tne effects of the flood and suitable ameliorative measures snail De taken Upstream ana downstream flooas loose aprons and filters if any of cross drainage works require canicular attention dunng inspection Any damage or settlement in them shall require special investigation to initiate timely and adequate measures for restoration *o avoia further damage during subsequent floods Lrewise training works sucn as groynes, guide bunds spurs etc shall also receive special attention dunng inspection regarding their stability and upkeep so that any damage and/or settlement of pitching and loose apron may not result m sniffing tne course of tne stream and attack the banks of the canal ano sides of cross drainage works Faithful recorc of history of benav«or of structures and damage to important structures dunng rainy season or otherwise ano repairs carried out shall be maintained m tne iog dooks of damage and repairs for the major structures Such record snail be made available during inspection by inspecting officers for their remarks An inspection register shall be maintained for all cross drainage works Its first few pages shall contain the hydraulic and structural design details of the cross drainage works in tne Performa given in Appendix A A few pages for the inspection reports of the inspecting officers for each year shall be maintained using tne Performa given in Appendix B 9.5.2 Damages to Cross Drainage Works and Remedial Measures Damages :c c oss drainage works are man.festeo oy the following r aj Silling ano.or Dermmg / cnoking m tne drainage channel. VWDSE Addis At 4 .□'/on iv/fh -??- Dpf j / C'es'on of Bale Gadula legation s Drainage Proie (Ministry ot Water and Energy • Federal Democratic Republic of Ethiopia Section - i Volume - Vll Operation and Maintenance Manual b) Seepage piping, scour and/or undermining c) Sloughing and/or caving d) Uplift and/or upheaval e) Structural cracks f) Out flanking/over-topping g) Sinking and/or differential settlements h) Growth of shrubs and other vegetation in the drainage barrels, j) Meandering of u/s reach and/or change in the drainage course in the vicinity of cross drainage worn, k) Choking of pressure relief valves,filters m) Bearings not functioning properiv n) Malfunctioning of gates and p) Leakage througn joints seals ana water stops 9 5.3 Remedial measures for the damages to cross drainage works Remedial measures for me aamages to cross drainage works are mentioned below a) Silting is a common feature observed in cross drainage works. Silting takes place in the bed of the approach channel drainage events and exit channel resulting m reduction of effective area for passage of water causing heading up of water to levels hianer than designed thereby over-topping the cross drainage works and canal Danks A meandering drainage course is likely to deposit silt in a disproportionate manner in the drainage course Regarding desilting of the bed and training of the drainage course can be considered. If choking due to debris has taken place, this shall be immediately cleared b) Undermining of the structures by deep scours during flood is one of the serious dangers to be guarded against The actual condition cannot be inspected during floods as the damage done cannot be seen or nothing comes to light as the scour pit gets filled up during receding floods i) The waterway of the cross drainage works shall be kept free from any obstruction by regular clearance of Sediment deposits, debris, trees stumps of wood etc found therein, ii) To replenish concrete biocks/stone apron provided in front of upstream ano downstream cutoffs as a regular maintenance measure, hi) Need to provide deeper cutoff or increasing length of existing floor may nave to be examined and adequate remedial' measures taken in case piping has set m as evidenced by cavities detected under floors ana/ iv) To prevent sucn cavities in the floor provision of compacted filter material to form sub grade snail be maae Where cavities have been noticed the WWDSE Addis Ababa in Association with •CT Pvt Ltd and ABCE P'.C 90- Detail Design of Bale Gadula Irrigation & Drainage Project October 2011I I I I I I r Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section - /. Volume - VII Operation and Maintenance Manual floor shall be removed above it, the cavities filled with compacted ’filter material and the floor repaired m addition to taking up the measures mentioned in item (in) above c) Sloughing and/or caving of the guide banks of approach and tail channel and canal banks at the junctions of cross drainage works are to be prevented Sloughing of guide banks may obstruct the water passage causing heading up of water with consequential over-topping of structure or undermining and scour downstream Adequate timely steps shall be taken after inspection to prevent sloughing or caving of banks, if anticipated. g) The barrel portion the exit and entry points shall be rendered free of shrubs and vegetation to avoid obstruction to the drain flow h) A meandering water course in tne vicinity of the cross drainage structure may result in embayment or endanger the downstream protection work Suitable training works may nave to be provided at such locations 9.54 Maintenance 9.5.4.1 Before Rainy season ai The apDroacn ana exit cnanneis in tne vicinity of cross drainage work shall be cleared of silt debris stumps orancnes of fees etc before the rainy season 0) Any cracks ana noies in upstream ana downstream floors of the cross drainage work shall oe duly repaired c) It shall oe ensured that water seals or aspnalt joints are intact Leakage if any snail be corrected Dy use of proper filler material d» Concrete blocks or stone apron provided in front of upstream and downstream cutoffs may be replenished as a regular maintenance measure 9 5 4 2 During Rainy Season a) During rainy season a vigilant watch is required in major cross drainage work Adequate qauge readings must be recorded during rainy season Return How and eddies near the cross drainage works need be watched bi All fallen out or aisturoea pitcnmg mat De made good 9 5 4 3 Post Rainy season a) The top levels of structure should oe recorded for getting information if there are any settlements bi If any gully orany caving is seen m canai banks or at the junction it should be treated with suitable selected soils c> If hair c acks are noticed r in the reinforced concrete slab or beams, they shall De carefully pressure-grouted with neat cement grout after tnorough investigation of the cause If wider cracks are noticed they snail be grouted with mortar grout of rich mix of cement ana sand If peeling off of concrete is noticed exposing •emrorcement tne damage may be repaired by Gruntina or iVWCSE Ac/d/s Abab ; // Asi abon • .01. Oetail Des :■ 9aie Gadula Irrigation & Drainage Prt fetrMinistry of Water and Energy - federal Democratic Republic of Ethiopia Section - l. Volume - VII Operation and Maintenance Manual Shotcreting with B R G fabnc after chiseling out the loose portions of concrete or mortar around the reinforcement and pre-wetting the surface with cement slurry To prevent leakage, appropriate sealant compound may be provided at all edges d) The gauges provided shall be repainted periodically to make them legible It would be preferable if enamel gauge plates are provided, as markings done on these plates donot fade out for a long time The gauges shall be checked for correctness e) Any damage to the bed and sides is to be recorded on the appropriate register and arrangements made to prepare it 9.6 Implementation of Maintenance Maintenance of Canals, Drains and their embankments will be done manually as the canal system has got small canals The canal system will be closed when there is no need of Irrigation and as it is possible to maintain it manually Main Canal will not need any desilting normally The ternary canals are small one which will be easier to maintain manually PP~S0C'a,'°n ",h b~Ka" DeSlgn Ba,e GadU,a October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Section -1 Volume - VII Operation and Maintenance Manual r Date of inspection--------------------------------- Date of iast inspection------------------------------------------ Fill the table given below REGISTER OF INSPECTIONS APPENDIX A PROFORMA FOR REPORTING INSPECTION OF CROSS DRAINAGE WORKS a; Name of the carrier cnannei b) Name of the stream c) Type of cross drainage work d) Location (chainage in km) of the canal; e) Catchment area of stream 0 No and size of openings of waterway: and g) Whether the repairs or remedial measures suggested during the last inspection have been carried out7 If so whether the same troubles are observed during the present inspection also7 If so what are the probable reasons for such recurrence7 Design discharge---------------------------- -cumecs Design Levels Upstream Design Level Downstream Maximum discnarge of the year in cumecs Observed levels Upstream Observed Leveis Downstream Date of compliance of last insoecticn emarKs----------- Remedial Nature of measures taken to I No Item Condition Repairs Approx Cost to rectify remedy the Remarks Required the defect if any Steps defects 1 Water way Drainage Channel 2 Foundations 3 Substructure 4 Superstructure 5 Canal Sanks 6 Guide banks 7 General conditions regarding tne alignment grades in long cross directions bearings and WWDSE Addis AoaDa in Association v.»th -93 ICT Pvt J J and -------- 1---n-—; --- 1 r~------ I Defa// Design of dale Gaduia irrigation & Drainage Project Octw 20iMinistry of Water and Energy - federal Democratic Republic of Ethiopia Section - I. Volume - VII Operation and Maintenance Manual supports and clearance between structural members 8 Other allied 11 1 r- 1 1 item if any 1 1 11 Signature------------------------------------------------------------ Name of Inspecting Officer------------------------------------------------------------------ Designation of Inspecting Officer---------------------------------------------------------- WWDSE Addis Abaha in Association with -94 Detail Design of Bale (Sadula Irrigation & Drainage Protect ICT Pvt Ltd and ABCE PL 0 * Qc herMinistry of Water and Energy - Federal Democratic Republic of Ethiopia EQUIPMENT REQUIRED FOR MAINTENANCE Section - I Volume - VII Operation and Maintenance Manual General The maintenance of canals drains, dykes in the Bale Gadula Irrigation Project is a simple affair as the canals will remain closed for some periods and hence maintenance can be done during closure periods and as the canals are small sized the maintenance will be done mostly manually However some machinery will be kept for some emergency. Machinery for the maintenance of embankment and side slopes The side slopes of the embankment of canals and drains have to oe kept smooth to prevent erosion and to allow mechanized weed control The best choice for this operation is tne motor grader and consists of a hydraulically operated mould board of 3 00 m width This blade will level and grade the side slopes of canals, dykes roads, ditches etc with the grader travelling alongside The soil or silt is brought on the bank or road and is moved further with the regular blade in a following pass After expenence gained more motor graders can De procured if they prove to De useful in comDarison of manual labor Machinery for control of Grasses and Weeds Control of grasses anc weeds can on the emoanKment ana slopes is necessary to discourage development of pests shrubs and trees which could damage the banks and to encourage soil binding grasses Moving car. be done by a frail mower at the end of an hydraulically operated boom This can De a special attachment to an agricultural tractor With such a tractor the maximum reach would be about 5 0m and working speed about 4 0 km per hr resulting in a net production of 2 0 km Machinery for the maintenance of flood proteaion embankments and river course Dykes or embankments require close supervision and routine maintenance to strengthen weak reaches each year Major maintenance is required at least once in 5 years to raise and strengthen eroded sections Removal of the obstructions in the river course has to be performed as and when required Normally it is not required These activities can be performed by a Bull Dozer with scraper box and wheel loader Equipment required Medium Excavator Tractor with -mower Bull Dozer with scraper box Generator 33 KVA for Emergency (When Electric power is not there) After 5 years more equipment if reauired can oe Drocjred 0/WDSE Addis Anaba m Association vrfr -j 1 1 1 . & ofairi , Octobe> 20 •Ministry of Water and Energy - Federal Democratic Republic of Ethiopia Jeeps Trucks / dumpers T and P-Pick axes hand shawals Pans lanterns torches Office equipment- computers / furniture Section - I, Volume - VII Operation and Maintenance Manual WWDSE Addis Aoaba in Association with -96- Detail Design of Bale Gadula ImgatiorTA Drainage Project ICT Pvt Lra ana AECE p» C October 2011Ministry of Water and Energy - federal Democratic Republic of Ethiopia Section - I. Volume - VII Operation and Maintenance Manual Appendix IlCrop Groups According to Soil Water Depletion Table 1-1 Crop Groups Group Crops 1 Omon, pepper, potato 2 banana, cabbage, grapes, pea, tomatoes 3 alfalfa, Dean, citrus, groundnut, pineapple, sunflower, watermelon, wheat — 4 cotton, maize, olive, safflower, sorghum, soybean, sugar Deet, tobacco Source Coorenbos and Kassam (1979) FAO-33 Table-l-2: Soil-Water Depletion Fraction (p) for Crop Groups and Maximum Evaporation (ETm) ETm mm/ day = ETc Group 2 3 4 5 6 1 7 8 9 10 1 0 500 0.425 0 350 0 300 0 250 0.225 0.200 0.200 0 175 2 0 675 0 575 0 475 0.400 0.350 0 325 0.275 0.250 0 225 3 0800 0700 0 600 0 500 0 450 0.425 0 375 0 350 0 300 4 0 875 0.800 0.700 0.600 0 550 0 500 0 450 0 425 0 400 Source Doorenbos and Kassam (1979) - FAO 33 Table - 1-3: Rooting Depth of Various Crops Rooting Depth (m) Crops ------------------------------------ —. - —, 0.3 to 0 50 0 50 to 1 00 1 00 to 1 50 —1 ------------------------- - ------------ Cabbage, celery lettuce, omon, pmapeals, potatoes, sisal, spinach vegetables Bananas beans, beets, carrots, clover, groundnuts, peas, peppers, soybeans, sugar beets Barley citrus cucumoer flax small grams maize melons, sunflower sweet potato wheat i kWVDSE Addis Auaba in Association with iC~ -fd and AE?E pLC 7 9 - Detail )>> jn Qf q GaJoia irrigation & Drainage Projec Oct tier 201 ‘Ministry of Water and Energy - Federal Democratic Republic of Ethiopia 1 SO to 2.00 Section - I. Volume - VII Operation and Maintenance Manual Alfalfa, cotton, deciduous, orchard, grapes, sunflower, sorghum, suga Table - I - 4 Available Water (AW) Holding Capacities for General Soil Types Soil Type AW (mm/m Depth of Soil) Coarse Sands - Gravelly Sands 40 - 70 Fine sands - Loamy Sands 70 - 100 Sandy Loams 120 - 160 Loam 180 - 220 Silt Loams 230 -270 Silty Clay Loams, Silty Clays, Heavy Clays 160 - 200 WWDSE Addis Ababa in Association with -93- Detail Design of Baie Gadula Irrigation & Drainage Project iC r p r and ABCE PLC October 2011Ministry ol Watei and Energy f ederal Democratic Republic of Ethiopia Appendix llhrigation Scheduling at tertiary Unit 11 U) Level i hie H 1 Sc hedulinr Made lor Block 1 1 in the BAGID PiojetI Section - I Volume VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled bv a Fanner at Once 3 Total inflow al SC-1-1 (cumcs) ICi level duty(l/i/ha)= TU Related Design Parameter s Furrow TU Irrigation Time by Parameters Families (da Soil Intake ys) Dischaige of Off takingCha nnel|m3/s ec) 20 15 10 Funow No of Spacing Furrows 130 8 1G4 1 255 fl 00 0 2 Total No of HHs in a TU j- 0 0235 No of Irrigation Days to Complete one TU (Days) 20 1.2 15 10 00 Categories of Cycles in the Rotation 02 Name ol length oft taking of TC AREA SN Channel in im) i ha) 1 TU 1-1-1 930 10 ■1 334 5 204 3 130 0 164 1 255 fl 334 5 679 0 0120 0 0300 0 75 0 75 2481 2828 450 8 513 8 5(»6 645 882 1005 1153 980 10 00 5 01 TU 1 1 2 1061 25 1991 35 1314 111/ 6 28 2 87 9 79 4 47 12 81 5 84 10 89 4 96 1st C yde 2nd Cycle 0 0420 25 00 35 2 28 7 2921 9 1486 14 261 18 64833 15 85 i . DSE Addis Ababa in Association with n I Pvt Ltd and ABCE PLC 99 Detail Design ol Bale Gadula Irngation & Drainage I ’ro/cct October 2011Ministry o/ Waft?/ and Energy f ede/aHJemocyafrc Republic of Ethiopia Table 11-2 Scheduling Made for Block 1-2 in the BAGID Project Section - /. Volume - VIII Operation and Maintenance Manual No of Irngators/HH 3 No of Furrows Handled by a Farmec at Once 3 Total inflow al SC-1-2 (l/s) 0 067 TCs levti duty(l/s/ha)= 12 1U Related Design Parameters I in low Parameteis TU Irrigation lime by Soil Intake 1‘amities |da;s) No of Irrigation Days Io Complete one TU (Days) Discharge of Off 20 15 10 08 02 20 15 10 08 02 1 olal Categories SN Name of off taking Channel length ofTC in im) AREA (ha) lakmgCha nnel(m3/s ec) Furrow Spacing No of Fuirows 130 8 164 1 255 8 334 5 284 3 No of HHs m a TU 130 8 164 1 255 8 334 5 679 of Cycles in the Rotation 1 TU 1-14 3 1326 55 0 0660 0 75 3537 642 6 806 1257 1643 139/ 55 00 1 30 1 63 2 54 3 32 2 82 1st Cycle 2 1U 1 14 4 1582 45 0 0540 0 75 4218 766 3 961 1499 1960 1666 45 on 1 89 2 37 3 70 4 84 4 11 2nd Cycle 2908 100 0 12 mo 3 4 6 8 7 I'.WDS/ Addis Ababa in Association with ICT Pvt ltd and ABCE PLC ■WO Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Mmistiy ol Water and Energy I let al Democratic. Republk of Ethiopia 1 able II 3 Scheduling Made for Block-1-3 in the BAGID Project Section - I. Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 Ro of Furrows Handled by a Farmer at Once 3 total inflow al SC-1 2 (I/S) ICi level duty(l/$/ha)> 12 111 Related Design Parameters Fur row Paranneters TU Irrigation limo by Soil Im ike Families (days) -——— - Total No of HHs 0 198 No of Irrigation Days to Complete one TU (Days) Categories of Cycles Name of off taking Channel Discharge of Off takingCha nnel(m3/s ec) 20 _ 15 10 02 284 3 in a TU 20 15 10 08 SN Furrow Spacin 9 No of Furrow s 02 in the Rotation length ARE of TC A in (m) (ha) 130 8 164 1 130 8 164 1 255 8 334 5 679 i z* J 4 ') 6 1U 131 1U 13 2 TU 1 3 3 TU i 3 4 TU 1 3 5 IU 1 3 6 1393 6 985 03 1292 5 1077 932 731 45 40 45 40 35 30 0 0540 0 0480 0 0540 0 0480 0 0420 0 0360 0 75 0 75 0 75 0 75 0 75 0 75 3716 2627 3447 2871 2485 1949 675 1 477 2 626 1 521 6 451 4 354 1 84 7 599 786 654 566 444 08 334 5 1727 1220 1601 1334 1154 45 00 40 00 4b 00 40 00 35 00 30 00 1 67 1 33 1 55 1.45 1 43 2 09 1 66 1 94 1 82 3 26 2 59 4 26 3 39 3 02 2 83 3 95 3.71 1st i yde 1 80 2 80 1 31 1 65 2 56 3 66 3 35 TU 1 37 621 25 0 0300 0 75 1655 300 6 3 77 255 8 1320 933 1225 1020 883 692 588 905 769 1467 103/ 1361 1134 981 770 653 25 00 1 34 2 61 a <4 ru 1 3 8 TH 13 9 599 295 20 10 0 0240 00120 0 75 0 75 1597 788 290 1 143 1 364 1R0 567 280 742 36b 631 311 20 00 10 00 1.61 1 68 2 02 3 15 3 42 4 12 1 59 1 99 3 11 4 07 3 62 2 88 3 36 3 15 3 11 2 85 2 90 3 50 3 46 2nd Ccycle ol Rotation with .i mjximum tr i if.ation time ol 8 5 days i - \D t Addis Ababa in Association with l( Pvt 1 Id and ABCF PL C 101- Detail Design ol Bale Gadula Irrigation & Drainage i it October 2011Ministry of lA/atei and Energy F tdeiai Democratic Republic of Ethiopia Section - I Volume - VIII Operation and Mamtenam e Manual Table II 4 Scheduling Made for Block 1 4 in the BAGID Project No of Irny ators/HH 3 No of Furrows Handled by a Farmer at Once 3 Total inflow at SC 1 2 (l/s) 0 034 TCs level dutyfl/s/hajs 12 TU Relate d Design Parameters Furrow Parameters TU Irrigation Time by Soil Intake Families (days) No of Irrigation Days to Complete one TU (Days) - 20 15 t0 08 02 20 15 10 08 02 SN Name of off taking Channel length of TC in (m) ARE A (ha) Discharge of Off takingCha nnel(m3/s ec) Total No of HHs in a TU Categories of Cycles in the Rotation Funow Spacing No of Fuirows 130 8 164 1 255 8 334 5 2e4 3 130 8 164 1 255 8 334 5 679 1 TU 1-4 1 1299 so 0 06 p 0 75 3464 629 4 790 1231 1609 1368 50 00 1 40 1 75 2 74 3 58 304 1st Cycle 2 TU-1-4-2 1274 50 0 06 0 75 3398 617 4 775 1207 1579 1342 50 00 1 37 1 72 2 68 3 51 1 3 TU 1-4-3 1185 25 0 03 1 75 1354 245 9 309 481 629 535 25 00 1 09 1 37 2 14 2 80 2 38 2nd Cycle 3758 125 0 15 125 3 8635 4 8471 7 5558 9 880387 8 398 1— « HWDSt Addis Ababa in Association with /c7 P\d Ltd and ABCE PLC 102- Detail Design of Bale Gadula Irngation & Drainage Pio/ect October 2011Ministry ot Watei and Eneigy - F > ./era/ Democratic Republic of Ethiopia Table -II 5 Scheduling Made for Block-15 in the BAGID Project Section - I Volume - VIII __________________________ Opeiatioi> and Mamienance M.mual No uf Irngators/HH 3 No of Furrows Handled by a Farmor al Once 3 Total inflow at SC 1 2 (I'M 0 084 TCi level duty(l/i/ha)« 12 TU Related Design Parameters Furrow Parameters TU Irrigation lune by Soil Intake Families (days) No of Irrigation Days to Complete one TU (Days) 20 15 10 08 02 20 15 10 08 02 ! SN Name of oil taking Channel length of TC In (m) ARE A (ha) Discharge of Off takingCha nnel(m3/s ec) Furrow Spacin 9 No of Furrow s 1 olal No of HHs in a TU Categories of Cycles in the Rotation 130 8 164 1 255 b 334 5 284 3 130 8 164 1 255 8 334 5 679 1 IU 1 5 1 1299 50 0 060 0 75 3464 629 4 HO 1231 1609 13bh 50 00 1 40 1 75 2 74 3 58 3 04 1st C y< le 1U 15 2 1274 50 0 060 0 75 1398 617 4 IIS 120/ 1579 1342 50 00 1 37 1 72 2 68 3 51 7 98 3 TU 1 5 3 1185 25 0 030 1 75 1354 245 9 309 481 629 535 25 00 1 09 1 37 2 14 2 80 1 2 38 2nd < yi le 3758 12S 0 150 ! 125 4 5 8 10 8 ______ f ».Sf T./j/s Al aba in Association with n Pvt Lt I and ABCE PL C Detail Design uf Bale Gadula Imyation & Uiamayu > uject Ch tober .011Ministry .>/ uVd/e/ and Energy ■ i edeial Democratic Republic of Ethiopia Section - / Volume - VIII Operation and Maintenance Manual Table II 6 Scheduling Made for Block-1-6 in the BAGID Project No of Irngalors/HH 3 No of Furrows Handled by a Farmer at Once 3 Total inflow al SC-1-2 (■/») —------- --------- 0 074 ICi level duty(l/s/ha)t 12 1U Related Design Paiamelisrs Furrow Parameters 1U Irrigation Tune by Soil Intake F amihes (days) No of Irrigation Days to Complete one TU (Days) Ir Name of length off taking ofTC AREA Discharge of Off takmgCha nnel(m3/s ec) 20 15 10 08 02 20 15 10 08 02 jN Channel in (m) iha) Fuiiow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 T olai No of Hits in a TU 130 8 164 1 255 8 334 5 679 Categories of Cycles in the Rotation 1 TU 16 1 824 2 1U1-6 2 1120 -- 3 1U 1-6-3 1294 35 40 35 0 042 0 048 0 042 0 75 0 75 0 75 2197 2988 3151 399 2 542 8 626 9 501 681 787 781 Uu2 122b 1021 1384 1603 HI.H 1 1HU 1363 35 00 40 00 35 00 -- - 1 27 1 59 1 51 1 89 1 99 2 50 2 48 3 24 2 95 3 86 3 89 5 09 2 75 1st lytic 3 28 2nd Cycle 4 33 in Cycle 3239 110 0 132 110 56 1 9 12 10 \VWDSE Addis Ababa in Association with ICT Pvt ltd and ABCE PLC 104- Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Ministry t>t Waler arid Energy - I edeial Democratic Republic ot Ethiopia table II 7 Scheduling Made for Block-1-7 in the BAGID Project Section - I Volume VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows H andled by a Faimer at Onco 3 Total inflow at SC-1 2 (l/S) 1.2 J ________________________ 111 Related Design Parameters Furrow Parameters 1U Irrigation lime by Soil Intake Families (days) — 2 0 1 5 1 U 08 02 Total No ol HHs in a TU 0.101 TCi level duty<l/s/ha)a -----■---- L--- No of Irrigation Days to Complete one TU (Days) I Njiho of Discharge length ARE of Off- of TC A takingCha •n Im) (ha) nnel(rn3/s ec) 1 5 1 0 08 02 1 Categories of Cycles in the Rotation SN off taking Channel Furrow Spacin 9 No of Furrow s 130 8 164 1 255 8 334 5 284 3 1 679 1 TU 1 7-1 99 88 5 0 006 2 TU 1-7 2 146 86 5 0 006 3 TU 1-7-3 /22 49 15 0018 4 TU 17-4 904 65 40 0 048 5 TU 1 7-5 843 92 30 0 036 6 TU 1 7 6 622 89 25 0 010 r~ ----------- --------------- --------------- 7 TU 1 7-7 678 52 15 0 018 — fl TU 1 7 8 575 15 0018 0 75 0 75 0 75 0 75 0 75 0 75 0 75 1 75 266 392 1927 2412 2250 1661 1809 657 48 4 71 1 350 0 438 3 408 8 301 8 328 7 1194 bl 89 439 550 513 3 79 412 150 95 139 684 857 800 590 643 233 >z. 182 895 1121 1046 772 841 305 105 155 761 953 889 656 714 259 5 00 5 CO 15 00 130 8 164 1 255 8 334 5 1 08 1 35 2.10 2 75 1 58 1 98 3 09 4 04 2 59 3 25 507 6 63 2 34 3 44 5 64 40 00 30 00 1 22 1 53 2 38 3 11 1st Cycle 25 00 1500 15 00 1 51 1 34 2 43 0 88 1 90 1 68 3 05 1 11 2 96 3 87 2 62 3 43 2 65 3 29 2 92 4 76 6 23 5 29 1 73 2 2b 1 92 2nd Cycle 4594 21 150 0 180 150 00 5 7 10 13 11 J l. VDSC n ldis Ababa in Association with /< 1 P\t l 11 and ARCE Pl C 105- Detail Design ul Bale Gadula Irrigation & Drainage Project October 2011Minisiiy of Walei and Energy - I edeial Democratic Republic of Ethiopia Section - I, Volume - VIII Operation and Maintenance Manual Table -II 8 Scheduling Made for Block-1-8 in the BAGID Project No of Irngators/HH 3 No of Furrows Handled by a Farmer at Once 3 Total inflow al SC-1-2 (l/s) 0.127 TCi level duty(l/s/ha)= 12 1U Related Design Parametc rrs Furrow Parameters TU Irrigation lime by Soil Intake Families (da yM No of Irngation Days Io Complete one TU (Days) Name of length SN off taking of TC Channel in (m) I AREA (ha) Discharge of Off takingCha nnel(m3/s ec) 20 15 10 08 02 20 15 10 08 02 Categories of Cycles in the Rotation Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 1 olal No of HHs in a TU 130 8 164 1 334 5 679 1 1U-1-8-1 2 TU-1-8-2 3 TU 1 8 3 _______ 4 TU 1-8-4 5 TU-1-8 5 6 TU 1-8-6 7 TU-1-8-7 498 752 793 74 7 777 729 794 20 30 30 0 024 0 036 0 036 1 34 1 35 1 42 1 68 255 8 2 62 1st Cycle 1 69 1 78 2 64 30 0 036 0 75 0 75 0 75 0 75 0 75 0 75 1328 2004 2114 1991 2071 1943 241 I 364 1 384 1 361 7 376 3 353 1 384 8 303 457 482 454 472 443 483 472 712 751 707 736 690 753 617 931 •J82 925 962 903 984 525 791 835 786 818 767 836 20 00 30 00 30 00 30 00 30 00 1 34 1 68 2 78 2 62 3 43 3 45 3 64 3 43 2 91 2.93 3 09 2 91 2nd Cycle 30 30 0 036 0 036 1 39 1 75 2 73 3.56 30 00 1 31 1 64 2 56 3.34 3 03 2 84 20 0 024 0 75 2118 20 00 2 14 2 68 4 18 547 4 65 1st Cycle 5089 190 0 228 190 00 10 13 20 26 22 _______ WWDSL Addis Ababa in Association with ICT Pct I td and ABCE PLC -106- Dctail Design of Bale Gadula Irngation & Drainage Project Octobei 2011Ministry ol Waler and Energy - I i Jeial Democratic Republic of Ethiopia Section - /. Volume - VIII Operation and Maintenance Manual Table -II 9 Scheduling Made for Block-1-9 in the BAGID Project No of Irrigators/HH 3 No of Furrows Handled by a Farmer at Once 3 lolal inflow at SC 1-2 (I's) 0.134 TCs level duty(l/s/ha)= 12 in Related Design Parameters Furrow Parameters TU Irrigation limo by Soil Intake Families (days) No of Irrigation Days to Complete one TU (Days) I Discharge 20 15 10 08 02 total No of HHs in a TU 20 15 10 08 02 Categories of Cycles in the Rotation Name of length | of Off- AREA SN off taking I of TC takingCha (ha) Channel in (m) nnel(m3/s ec) 1 HJ 1 9 1 I 1095 35 0 042 TU 19 2 1500 50 0 060 3 TU 1 9-3 1582 50 0 060 1 4 TU 1 9-4 1071 35 0 042 5 TU 1-9-5 784 30 0 036 Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 0 75 0 75 0 75 0 75 0 75 2919 3999 4219 530-1 726 5 766 5 665 911 962 1037 1421 1499 1 156 1858 19 Ml 1153 1579 lLb6 35 00 50 00 50 00 1 68 1 61 1 70 2.11 3.29 2 03 2 14 3 16 3 33 4 31 4 13 4 3b 3 66 3 51 3 70 1st Cycle 2nd Cycle 2855 2091 518 7 379 8 651 476 1014 743 B27 971 1127 826 35 00 30 00 200 00 1 65 1 41 2 07 3 22 4 21 1 76 2 75 3 60 3 58 3 0b 1 st Cycle 6031 200 0 240 8 10 16 21 18 VV i M>S£ Addis Ababa in Association will) I 1 Pvt III and AfJCE PIC •107- Detail Design ot Bale Gadula Imqation & Drainage Pro/ect October 2011Ministry <>l Watei and Energy I mieral / democratic Republic of Ethiopia r --------------------------------------------------------- --------------------------------- Table 11-10 Scheduling Made for Block! 10 in the BAGID Project Section I Volume VIII Operation and Maintenance Manual No of Irngators/HH 3 No of Furrows Handled by a Farmer al Once 3 Total inflow at SC-V2 (l/s) 0 208 TCs level dutyfl/s/ha)> 1 2 ITT ^ 4 ---- = TU Related Design Parameters Fuirow Parameters TU Irrigation Time by Soil Intake Families (days) Total No of HHs No of Irrigation Days to Complete one TU (Days) Categories of Cycles i th Discharge of Off- takingCha nnel(m3/s ec) 20 15 ne Rotation SN off taking Name of length AREA ofTC Channel in (m) (ha) Furrow No of Spacing Furrows 130 8 164 1 In a 1 0 08 02 2 0 1 0 08 02 TU — 255 8 334 5 284 J 130 8 164 1 255 8 334 5 679 1 Til 1 10 1 7S4 2 1U t 10 2 1753 3 TU 1 10-3 2018 4 TU 1 10 4 2030 5 TU 1-10 5 1483 6 TU-1 106 1182 □ 75 0 75 — 3 46 2 94 1st Cycle 3 71 3 15 0 75 0 75 0 75 1 75 7 TU 1 10-7 938 30 0 036 os 0078 75 0 090 80 0 096 GO 0072 45 0054 10 0012 2 75 2012 4623 5333 5413 3953 1351 682 365 4 458 715 849 U 1UL5 1660 977 fl 1227 1912 98 3 5 1234 1923 718 2 901 1405 245 4 308 480 124 0 156 242 935 794 2171 1845 2501 2125 2515 2138 183/ 1561 628 533 317 269 30 00 1 35 1 70 2 65 r"~ 65 00 1 45 1 82 284 75 00 1 82 2 83 80 00 1 37 1 71 2 67 60 00 1 33 1 67 2 60 45 00 0 61 0 76 1 19 1000 1 38 1 73 2 69 3 70 3 15 2nd Cycle 3 49 2 97 3 40 2 89 1 55 1 32 3 52 2 99 1st Cycle 10158 310 0438 31000 9 11 17 23 19 WWDSE Addis Ababa in Association with ICT Pvt Ltd and ABCE PLC -108 Detail Design of Bale Gadula Irrigation & Drainage Pioject October 2011Ministry ol Watei and Energy - I feral lh mocratic Republic of Ethiopia Section - / Volume VIII Operation and Maintenance Manual 1 .ible 11-10 Scheduling Made for Block-1- 10 in the BAGID Project No of Irrigators/HH L’ No ol Furrows Handled Dy a 1 arrnei al Once 3 1 ctal inflow at SC 1 2 (Vl) 1 0 208 TC» level duty(l/i/ha)” 1 2 -“ 11 TU Related Design Paiamelers F urrow P aiamelers TU Irrigation Tim e by Soil Intake Families (days) Name of Discharge of on length lakingCha ofl Liking of TC AREA nneliml/s ul l tunnel m (mi (ha) •c) 20 1 5 Furiow No ot Spacing F U'tOWS 130 8 Ib4 1 1 0 b 8 02 15 10 08 02 255 8 334 5 284 3 No of Irrigation Days Io Complete one TU (Days) 20 lotai No of HHs m a TU 130 8 164 1 255 8 C aiegories of C ycles in the Rotation 1U I 10 1 754 j 1 ru i io 2 1753 1 TUI 10 3 2018 4 111 1 10 4 2030 5 TH 1 10-5 1483 6 TU I 106 1182 7 TU 1 10 7 . 938 30 2012 4673 5383 5413 3953 30 00 65 00 75 00 80 00 60 00 45 00 1 35 1 45 1 45 1 37 1 33 0 61 1 70 1 82 2 65 2 84 Bl lyilr 65 75 80 60 45 10 0 036 0 75 0 078 0 75 0 090 0 75 0 096 0 75 0 072 0 75 0 054 1 75 0012 2 75 365 1 849 0 977 8 983 5 718 2 245 4 124 0 458 10b5 1227 1234 901 308 156 '15 lbbO 1912 1923 1405 480 242 915 21 '1 2501 2515 1837 b?8 317 AI4 1845 2125 2138 1561 533 269 1 82 1 71 167 0 76 1 73 2 83 2 67 2 60 1 19 682 1000 1 38 2 69 334 5 679 3 46 2 94 3 71 3 15 3 70 3 15 3 49 2 97 3 40 2 89 r• 1 32 3 52 2 99 2nd Cycle 3rd Cycle 1st Cycle ]— 10158 310 0 438 31000 9 11 17 23 19 1111 DSt 'Udis Ababa in Association with li ' Pvt Lid and ABCE PLC 109- Detail Design ot Bale Gadula Irrigation & Drainage Pro/ect Octobet 2011Ministry of Watei and Energy f edeial Democratic Republic of Ethiopia fable 11-11 Scheduling Made for Block 1-11 in the BAGID Project Section - /. Volume - VIII Operation and Maintenance Manual No of Irngators/HH 3 No of Furrows Handled by a Farmer at Once 3 Total inflow at SC 1-2 (l/s) 0 114 --— TCs level duty(l/j/ha)= 12 TU Related Design Parameters Furrow Parameters TU Irrigation Fan Time by dies (da Soil Intake ys) Total No of HHs NO Of Irrigation Days to Complete one TU (Days) 20 15 10 08 02 20 15 10 08 02 SN Name of off taking Channel length of TC In (m) AREA (ha) Discharge of Off- takingCha nnel(m3/s ec) in a TU Categories of Cycles in the Rotation Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 TU 1 11 1 1953 90 0 108 ■■ ■ 0 75 5207 945 9 1187 1850 2419 2056 90 00 1 17 1 47 2 28 2 99 2 54 1st Cycle 2 TU 1 112 1281 45 0 054 0 75 3415 620 3 7 28 1213 1586 1348 45 00 1 53 1 92 3 00 3 92 3 33 3 TU 1-11 3 S09 15 0018 0 75 1358 246 8 310 483 631 536 15 (X) 1 83 2 29 3 57 4 67 3 97 4 TU 1114 288 10 0012 0 75 768 139 5 175 273 35 7 303 10 00 1 55 1 94 3 03 3 96 3 37 5 TU 1 11 5 231 10 0012 075 617 112 1 141 219 287 244 10 00 1 25 156 2 44 3 19 2 71 2nd Cycle 4262 170 0 204 170 00 7 9 14 19 16 VVWUSE Addis Ababa in Association with IC7 Pvt ltd and ABCE PLC Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Ministry of Water and Energy - f ederal Democratic Republic of Ethiopia 1 able II 12 Scheduling Made for Block-l*12 in the BAGID Project Section - I. Volume - VIII Operation and Maintenance Manual No ot lingaiois/HH 3 No of Fuirows Handled Once by a Fannei al 3 total inflow at SC-1 2 (l/s) 0 131 TCs level duty(l/s/ha)= J2 1 U Related Design ParamekSIS Discharge of Off Name of length lakingCha i off taking of TC AREA nnel(m3/s Channel in (m) tha) ec) 1459 9 Fuirow P aiameteis TU Irrigation lime by Soil Intake Families (days) No of Irrigation Days Io Complete one TU (Days) 20 15 10 00 02 20 15 10 08 02 'N Furiow Spacing No of Furrows 130 8 1b4 1 255 8 331 5 284 3 T olal No ol HHs in a TU 130 8 164 1 255 8 334 5 6 79 Categories of Cycles In the R alalion 1 1U 1 12 1 111 1 12 2 9 45 0 054 ________ 12190 9 40 0 048 1268 7 5 45 0 054 0 75 0 75 389j 3251 707 3 590 6 153/ 1284 1 75 1 64 2 19 2 06 3 42 4 47 3 80 i si Cycle 2 1383 1155 1MU9 1510 3 21 4 20 3 57 3 4 5 TU 1 12 3 0 75 3383 2569 2060 614 6 466 8 374 2 88/ 241 771 586 4 70 159 1202 913 732 247 1572 11*34 95/ 323 1336 1015 813 45 00 40 00 45 00 35 00 1S2 1 90 2 97 3 88 TU 1 12 4 TU 1 12 5 TU 1 12-6 963 48 772 49 609 13 35 0 042 1 48 1 86 2 90 3 79 30 20 0 036 0 024 0 75 0 75 30 00 1 39 1 74 2 71 2nd Cycle -------- i ■ 1 75 696 126 5 2 75 20 00 0 70 8 0 88 1 37 3 54 1 80 3 30 3 22 3 01 1 53 6 5684 195 0 258 195 00 10 15 20 17 H \D i Addis Ababa in Association with h ' P\t ltd and ABCE PLC 111 Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Ministry of Watei and Energy - ‘ edeial I lemouatic Republic of Ethiopia Table -11-13 Scheduling Made for Block-1-13 in the BAGID Project Section - I. Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled by a Farmer at Once 3 total inflow at SC-1-2 (l/s) 0 077 TCs level duty(l/s/ha)= 12 TU Related Design Parameters Furrow Parameters TU Irrigation Time b) Families (da Soil Intake ys) Total No of HHs No Of Irrigation Days to Complete one TU (Days) — Categories of Cycles In the Name of length Discharge of Off 20 15 10 08 02 in a TU 20 15 10 08 02 Rotation SN off- taking Channel of 1C in (m) AREA (ha) takingCha nnel(m3/s ec) Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 TU 1 12 1 1873 65 0078 0 75 4995 907 5 1139 1775 2321 1973 65 00 1 55 1 95 3 03 397 3 37 1st Cycle 2 TU 1 12 2 1372 50 0 060 0 75 3659 664 8 834 1300 1700 1445 50 00 1 48 1 85 2 89 3 78 3 21 2nd Cycle 3246 115 0 138 15 3 4 6 8 7 IVWDSf Addis Ababa in Association with l( T Pvt I td and ABCE Pl C ■112- Detail Design of Bale Gadula Irngation & Drainage Project October 2011Ministry of Water and Energy - I t deial Democratic Republic of Fthiopia Table II 15 Scheduling Made for Block-1-15 in the BAGID Project Section - I, Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled by a Farmer at Once 3 1 olal inflow at SC 1-2 (Ms) 0 067 TCs level duty(l/s/ha)= 12 TU Related Design Parameters Furrow Parameters TU Irngation Tune by Soil Intake Families (days) No of Irrigation Days to Complete one TU (Days) Discharge Name of length of Off AREA SN off taking of TC takingCha (ha) Channel in (m) nnel(m3/s ec) 20 15 10 08 02 Total No of HHs in a TU 20 15 10 08 02 Categories of Cycles in the Rotation Furrow Spacing No of Furrows 130 0 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 2 TU 1 15 1 1336 TU 1 15-2 1104 TU 1 15 3 796 50 50 JO 0 060 0 060 0036 0 75 U 75 1 75 3562 2945 910 647 0 5.35 0 165 3 812 6/1 207 1265 1046 323 1655 1 368 423 1406 1163 359 50 00 1 80 2 81 3 13 1st Cycle 5000 30 00 1 44 1 19 061 1 49 0 77 2 33 1 20 3 68 3 04 1 57 2 58 2nd Cycle 1 33 2440 100 0 120 100 3 3 5 7 _____ 6 1 ll. VD E Addis Ababa in Association with It I r\t Ltd and ABCE PLC 113- Delail Design nt Bale Gadula Irrigation & Drainage Project October 2011Ministry of Walet and Energy F ederai Democratic Republic of Ethiopia Table II 14 Scheduling Made for Block-1-14 in the BAGID Project Section - I Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled by a Farmer at Once 3 Total inflow at SC 1-2 (cumcs) 0 007 TCs level duty(l/s/ha) = 12 TU Relate d Design Paramete rs Furrow Parameters TU Irrigation Time b} Families (da Soil Intake ys) Total No of HHs No of Irrigation Days to Complete one TU (Days) SN length of TC AREA Funow No of 20 15 10 08 02 in a TU Categories of Cycles in the Rotation Name of off taking Channel 20 15 10 08 02 In (m) (ha) Discharge of Off takingCha nnel(m3/s ec) Spacing Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 TU 1 14 1 199 5 0 0060 0 75 531 96 5 121 189 247 210 500 2 14 2 69 4 19 5 49 4 66 2 TU 1-14 2 489 25 0 0300 0 75 1304 236 8 297 463 LOG 515 25 00 1 05 1 32 2 06 2 69 2 29 3 1U 1-14-3 845 30 0 0360 0 75 2253 409 4 514 801 1042 890 30 00 1 52 1 90 2 97 3 88 3 30 4 IU 1-14-4 703 25 0 0300 0 75 1875 340 6 427 666 871 740 25 00 1 51 1 90 2 96 3 87 3 29 5 TU 1-14 5 333 15 0 0180 0 75 888 161 4 202 316 413 351 15 GO 1 20 150 2 34 3 06 2 60 6 TU 1 14 6 334 10 0 0120 0 75 890 161 7 203 316 413 351 10 00 1 80 2 25 3 51 4 59 3 90 1st Cycle of Rotation with a 7 TU 1 14 7 538 25 0 0300 0 75 1435 260 8 327 510 667 567 25 00 1 16 1 45 2 27 2 96 2 52 Irngation Time of 5 5 8 IU 1-14 8 1291 45 0 0540 0 75 3442 625 3 784 1223 1599 1359 45 00 1 54 1 94 3 02 3 95 3 36 days 9 TU I 14 9 1234 45 1 0 0540 0 75 3290 597 6 750 1169 1528 1299 45 00 1 48 1 85 2 89 3 77 3 21 2nd C cycle of WWDSI Addis Ababa in Association with ICT Pvt Ltd and ABCE PLC ■114 Detail Design of Bale Gadula Irngation & Drainage Project October 2011Ministry of Waler and Fnergy • f e de rat Democratic Republic of Ethiopia Section - I. Volume - VIII Operation and Maintenance Manual 10 11 12 13 14 15 16 TU 1 14 10 684 25 0 0300 1 85 2 88 3 77 TU 1 14 11 1U 1 14 12 TU 1 14 13 TU 1 14 14 637 475 20 0 0240 2 15 3 36 4 39 10 0 0120 321 500 Rotation with a mjMimum iirigation lime of 6 5 days 459 597 10 20 IL 1 14-15 TU 1 14 16 584 262 20 0 0120 0 0240 0 0240 0 75 0 75 0 75 0 75 0 75 0 75 1825 1700 1268 1223 1593 1558 3 10 4 83 10 00120 0 75 699 331 5 30R 8 230 3 222 1 289 4 283 0 12 7 0 416 387 289 2 29 363 155 159 648 604 450 134 566 554 248 848 7 90 589 568 740 2 24 3.5 721 671 501 483 629 615 276 25 00 20 00 1000 1000 20 00 20 00 1000 1 47 1 72 2 56 2 47 1 61 1 57 1 41 2 02 1 97 1 77 3 14 3 08 2 76 6 54 6 31 4 11 4 02 3 61 3 20 3 73 5 56 5 36 3 49 3 42 3 07 9665 3 6 340 0 408 I*. \W. I Addis Al aba in Association with H f Pt I Ltd and ARCE PLC Detail Design of Bale Gadula lingation & Drainage t io/ecf October 2011Ministry uf Watei and Eneigy - f eik i >1 Democratic Republic of Ethiopia Table 11-16 Scheduling Made for Block-1-16 in the BAGID Project Section - I. Volume - VIII Operation and Maintenance Manual No of Irrigators/HH — ~ _ 3 No of Furrows Handled by a Farmer at Once 3 Total inflow at SC-1-2 (!/•) — 0 131 TCs level duty(l/s/ha) = J2 TU Related Design Parameters Furrow Parameters TU Irrigation Time by Soil Intake Families (da ys) No of Irrigation Days to Complete one TU (Days) 2 0 1 5 1 0 0 8 02 20 15 10 08 02 Categories of Cycles in the Rotation SN Name of off- taking Channel length of TC in (m) — Total No of HHs in a TU AREA (ha) Discharge Of Off takingCha nnel(m3/s ec) Furrow No of Spacing Furrows 334 5 284 3 130 8 164 1 255 8 334 5 679 1 TU 1 16 1 2 TU 1 16 2 3 TU 1 16 3 4 TU-1-16 4 1507 60 1712 925 55 45 35 0072 0 066 0 054 0 042 0 75 0 75 0 75 0 75 4019 4567 2466 2849 130 8 164 1 730 1 916 829 b 1041 448 0 562 517 6 649 255 8 1428 1622 876 1012 1867 2122 1146 1324 1587 1803 9/4 1125 60 00 1 35 55 00 1 68 45 00 1 11 1 70 2 10 2 64 3 28 3 46 4 29 1 39 2 16 2 83 2 94 1st Cycle 3 64 2nd Cycle 2 40 1st Cycle 1068 35 00 1 64 2 06 4 20 3 57 2nd Cycle 5213 195 0 234 115 3 4 3 21 6 87 _______ WWDSE Addis Ababa in Association with ICT Pvt Ltd and ABCE PLC 116- Detail Design of Bale Gadula Irrigation & Drainage Project Octobci 2011Ministry of Waler and Energy - F ederal Democratic Republic of EthiopiaOperation and Maintenance Manual Table II 17 Scheduling Made for Block-1-17 in the BAGID Project Section - / Volume - VIII No of Irngalors/HH 3 No of Funows Handled by a Faimei al Once 3 total inflow at SC-1-2 (US) 0 104 TCi level duty(l/i/ha) = 12 Furrow Parameters TU Irrigation Time by Soil Intako Families (days) No of Irrigation Days to Complete one TU (Days) r i 1 U Related Design Parameters 1 i ■ Discharge Name of lenglh of Off- 20 15 10 08 02 Total No of HHs In a TU 20 15 10 08 1 02 Categories of Cycles in the Rotation SN off taking ofTC Channel in (m) AREA (ha) laklngCha nnel(m3/s ec) Furrow Spacing No of Furrows 130 8 164 1 255 8 JJ4 5 284 3 130 8 I 164 1 I I 255 8 i 334 5 1 679 1 2 3 4 5 6 It* 1 17 1 1149 III 1 17 2 1318 ID 1 17-3 1433 11J 1 17-4 1/81 TU 1 17 5 1114 TU 1 17-6 710 25 35 45 0 030 0 042 0 054 0 75 0 75 0 75 0 75 0 75 0 75 3061 3514 3822 556 7 638 3 691 4 35 00 45 00 2 47 2 03 1 71 4 84 3 96 6 33 5 18 2 15 3 35 4 38 50 0 060 4749 862 8 6)8 801 8/1 1082 1210 ) 387 1509 1875 25 00 3 10 2 54 50 00 192 2 41 3 75 4 90 40 2971 539 7 1 88 2 93 3 83 20 0 048 0 024 1895 344 2 677 432 1089 1248 1358 1687 1056 673 1424 1612 17/6 2206 1380 880 1173 748 40 00 20 00 1 50 1 91 2 40 3 74 4 89 5 38 4 40 1st Cycle 1 3 73 | 2nd Cycle I 4---------------------- 4 17 3 26 3id Cycle 4 16 2nd Cycle 5681 155 0 186 60 5 6 9 12 1 10 i .\D' f A/is Ababa in Association with h IP.l Li I and ARCE PLC Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Mmisti} i»/ Watei and Energy l edtva/ Democratic Republic of Ethiopia Table 11-18 Scheduling Made for Block 1-18 in the BAGID Project Section - / Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled by a Fanner at Once 3 Total Inflow al SC-1-2 (l/s) 0 060 TCs level duty(l/s/ha)= 12 TU Relate d Design Parameters Furrow Parameters TU Irrigation Time by Soil Intake Families (days) Total No of HHs No of Irrigation Days to Complete one TU (Days) Discharge of Off takingCha nnel(m3/s ec) 20 15 10 08 02 In a TU 20 15 10 08 02 Categories of Cycles in the Rotation SN Name of off- taking Channel length of TC in (m) AREA (ha) Fuirow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 i 1 2 TU 1 18 1 2540 70 0 084 0 75 6772 1230 3 1541 2406 3146 2674 70 00 1 95 2 45 3 82 4 99 4 24 1st Cycle 1U 1-18-2 94 J 20 0 024 0 75 2SJ1 45b 1 572 892 1166 991 20 00 2 53 3 18 4 96 6 48 5 51 2nd Cycle 3481 90 0 108 90 4 6 9 11 10 _______ IVWDSf Addis Ababa in Association with IC1 Pvt ltd and ABCE PLC 118 Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Mtnishy of Watei and Energy - F c deial Democrat". Republic of Ethiopia Table II 19 Scheduling Made for Block-1-19 in the BAGID Project Section - / Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled by a Farmer al Once 3 Total inflow at SC-1-2 (!/•) 0 070 TCs level duty(l/s/ha)« 12 TU Related Design Parameters Furrow Parameters TU Irrigation lime by Soil Intake Families (days) No of Irrigation Days to Complete one TU (Days) 20 15 10 08 02 Total No of HHs in a TU 20 15 08 02 Categories of Cycles in the Rotation SN off taking of TC Channel in (m) — Discharge Name of length of Off AREA 10 (ha) takmgCha nnel(m3/s ec) Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 1U 1 19 1 1160 35 0 042 2 1U 1 19 2 1168 35 0 042 3 1U 1 19 3 1349 35 0 042 2329 105 0 084 0 25 0 75 0 75 3094 562 1 566 0 653 7 205 /to 820 1099 1107 1278 1438 1148 16/2 1222 1230 1421 35 00 35 00 35 00 1 78 1 80 2 08 2 24 3116 3598 2 25 2 60 3 49 3.51 4 06 4 56 4 60 5 31 3 88 3 91 4 51 1st Cycle 2nd Cycle 70 4 4 7 9 8 ___________ I*,D' f Addis Ababa in Association wilh i f P.» 11 i miJABCE PI C H9- Detail Design of Bale Gadula Irrigation 4 Drainage Project Oclobei 2011Ministry ol Watei and Eneiyy !• al l’einorr<)ti( Republic of Ethiopia lable -11-20 Scheduling Made for Block 1-20 in the BAGID Project Section - I Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled by a Fanner at Once 3 Total inflow at SC-1-2 (l/s) 0 067 ICs level duty(l/s/ha)* 12 TU Related Design Parameters Furrow Parameters TU Irrigation Fam Time by boil Intake dies (days) Total No of HHs No of Irrigation Days to Complete one TU (Days) I Name of length Discharge of Off 20 15 10 08 02 In a TU 20 15 10 08 02 Categories of Cycles in the Rotation — SN off- taking Channel of TC in (m) AREA (ha) takingCha nnel(m3/s ec) Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 TU-1-20 1 1306 SO 0 060 0 7S 3482 632 6 794 1237 1618 1375 50 00 1 41 1 76 2 75 3 59 3 06 1st Cycle 2 1U 1 20 2 962 20 0 024 0 7S 2566 466 1 585 912 1192 1013 20 00 2 59 3 25 5 06 6 62 5 63 3 1U 1-20 3 1122 30 0 036 0 75 2993 543 7 682 1063 1 — 1390 1182 30 00 2 01 2 53 3 94 5 15 4 38 2nd Cycle 2268 100 0 120 100 4 5 8 10 9 WWDSE Addis Ababa in Association with ICT Pvt L td and ABCE Pl C 120 Detail Design of Bale Gadula lingalton & Drainage Project Oclobei 2011( T Pvl I tci and ABCE PI C Octobei 2011 i Mmistiy ol Walei and Energy ■ Fede/al Democratic Republic of Ethiopia Section - I Volume - VIII Operation and Maintenance Manual Table 11-21 Scheduling Made for Block-1-21 in the BAGIO Project No of Irnyalors/HH 3 No of Furrows Handled by a Farinei at Once 3 total inflow at SC-1-2 (l/«) 1U Related Design Parameters Furrow Parameters 0 111 No of Irrigation Days to Complete one TU (Days) TU level duty(l/s/ha)= 12 TU lingation Time by Soil Intake Families (days) i Categories of Cycles i th 20 1 5 1 0 08 02 Total No of HHs In a TU 20 15 10 08 02 ne Rotation Name of length SN off taking of TC Channel in (m) AREA (ha) Discharge of Off takingCha nnel(m3/s ec) Furrow Spacing No of Furrows 130 8 164 1 255 8 JJ4 5 284 J 130 8 164 1 255 8 334 5 6,9 1 2 3 4 5 TU 1 21 1 1007 40 70 15 20 0 048 0 084 0018 0 024 0 75 0 75 0 75 0 75 0 75 2686 4673 1288 1374 1548 488 0 8189 234 0 249 6 281 2 612 1065 294 113 353 954 1660 458 488 550 1248 1061 1845 509 542 40 00 70 00 15 00 20 00 1 16 1 35 1 73 1 70 1 69 2 17 2 65 3 47 1U 1 21 2 1752 1U 1 213 483 TU 1 21 4 515 2 64 3 39 3 45 4 43 1 39 1 74 2 71 3 55 1st Cycle 2 93 3 fi 2nd Cycle 3 01 1U 1-21 5 580 2760 20 0 024 2171 598 638 719 611 20 00 1 56 1 96 3 06 4 00 1st Cycle 165 0 150 165 7 9 14 19 3 40 16 [A WD1 f Addis Ababa in Assoc i at ion with h 1 P.l ltd and ABCE PLC 121 Detail Design of Bale Gadula lingation & Drainage I laject Octobei <011'.'mi iiy nf Wafe/ and Energy • j/i Republic of Ethiopia Section - I Volume - VIII Operation and Maintenance Manual Table 11-22 Scheduling Made for Block-1-22 in the BAGID Project No of Irrigators/HH 3 No of Furrows Handled by a Fanner at Once TCs level duty(l/i/ha) = 12 1U Related Design Parameters Furrow Parameters TU Irrigation Time by Soil Intake Families (days) Total No of Irrigation Days to Complete one TU (Days) -------------- r length of TC 20 | Categories of Cycles in the Rotation Name of SN off- taking i AREA (ha) Discharge of Off takingCha nnel(m3/s ec) Furrow No of .. . 1 Channel in (m) Spacing Furrows 130 8 1 TU 1-22 1 2169 — 2 TU 1 22 2 1608 3 TU 1-22-3 3484 85 60 90 0 102 0 072 0 108 0 75 0 75 0 75 5783 4289 9291 4 TU 1 22 4 2311 40 0 048 0 75 6163 1050 5 ! 779 2 1687 9 | 1119 7 2nd Cycle 1st Cycle 9572 275 0 282 \VWDSE Addis Ababa in Association \nith ICT Pvt ltd and ABCE PLC 122- Detail Design ot Bale Gadula Irrigation & Diamage Project October 2011M 'Shy <»/ iVatei and Eneig\ i Ictal L)i mocraln Republic ul Ethiopia 1 able II 73 Scheduling Made for Block-1 23 in the BAGID Project Section - / Volume - VIII Operation and Maintenance Manual No ol Imgalors/HH 3 No ol Furrows Handled by a Farmer al Once 3 1 oiat *nfiow at SC-1-2 (Vs) 0 090 TC» level dut>(l/Vh4l 12 1U Related Design Parameters 1 uirow Paiamelers TU i>ngatiun Time by Soil Intake Famities (days) No of Irrigation Days to Complete one TU (Days) Discharge of Off length lakingCha 20 15 10 08 02 20 15 10 08 02 Name ol off taking of TC AREA nnel(m3/s . >N Channel in (m) (ha) ec) f urrow Spacing No of Furrows - 130 fl 57) 4 572 0 5b0 3 104 1 719 718 103 793 255 8 1121 1119 1096 1236 334 5 1466 14b) 1 1)3 1616 284 3 Total No ol HHs m a TU 130 8 164 1 255 8 334 5 679 Categories of C ycles in the Rotation 1 HI 1 23 1 1184 40 0 048 2 TU 1 23-2 1181 40 0 048 1 HI t 23 3 1157 40 0 048 4 TU-1 23-4 1305 IS 0018 0 75 0 75 0 75 0 >5 315/ 3149 3084 3479 1246 124) 1218 40 00 40 00 40 00 1 59 1 59 1 Sb 2 00 1 99 1.95 3 12 3 11 3 04 4 07 4 06 3 98 6)2 0 1374 15 00 4 68 5 87 9 16 11 97 J 46 - 3 45 Bl Cycle 3 38 10 18 2nd Cycle 4826 135 0 162 « 135 9 12 18 24 20 \D r Addis Al iba in Association with P\. fill and ARCE Pl C 123 Detail Design ol Bale Gudula Imgation & Dunnage I inject October 2011Minrstiy of Walei and Energy ■ Federal Demociahc Republic of Ethiopia Table II 24 Scheduling Made for Block 1-24 in the BAGID Project Section - I. Volume - VIII Operation and Maintenance Manual No of Irrigalors/HH 3 No of Furrows Handled by a Fanner at Once 3 0 111 TCs level dufy(l/i/ha)= TU Related Design Parameters Furrow Parameters 1U Irrigation lime by S Families (day Total inflow at SC-1-2 (!/•) » oli Intake s) Total No of HHs 12 No Of Irrigation Days to Complete one TU (Days) Categories of Cycles In the Discharge of Off- takingCha nnel(m3/s ec) 20 15 10 08 02 in a TU 20 15 10 08 02 Rotation Name of length SN oft taking oflC Channel in (m) AREA (ha) Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 TU-1-24 1 2 TU-1-24 2 3 TU-1-24 3 2210 1420 70 45 0 75 1713 50 0 084 0 054 0 060 0 75 0 75 5893 3786 4569 1070 6 687 7 830 1 1343 863 1041 2094 1345 1623 2738 1759 2123 2327 1495 1804 2 13 3 32 3 32 3 61 4 35 4 34 4 72 3 69 3 69 4 01 5343 165 0 198 70 00 45 00 50 00 165 1 70 1 70 1 84 136 1st Cycle 2 13 2 31 171 2nd Cycle 266 348 690 WVVDSF Addis Ababa in Association with ICT Pvt ttd and ABCF PLC 124- Detail Design of Bale Gadula Irrigation & Drainage Project Octobei, 2011Ministry o/ Waler and Energy I edeial Democratic Republic of Ethiopia 1 able II 25 Scheduling Made for Block 1 25 in the BAGID Project Section - /, Volume - VIII Operation and Maintenance Manual No of Irrigators/HH 3 No of Furrows Handled by a Fanner al Once 3 Total inflow al SC-1-2 (l/s) 12 Furrow Parameters TU litigation lime by Soil Intake Families (day*.) 0 000 No of Irrigation Days Io Complete one TU (Days) TCs level duty(l/s/ha) = TU Related Design Parameters I Discharge Name of length of Off- 20 15 10 08 02 Total No of HHs in a TU 20 15 10 08 02 Categories of Cycles in the Rotation SN off taking of TC takingCha Channel in (m) nnel(m3/s ec) AREA (ha) Furrow Spacing No of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 255 8 334 5 679 1 2 3 IU 1 25 1 1U-1 25-2 TU 1 25 3 TU 1-254 TU 1 25 5 TU 1-25-6 2209 1351 1083 757 548 50 40 40 30 0 060 0 048 0 048 0 036 0 75 0 75 0 75 0 75 0 75 0 75 5890 3602 2887 2018 1070 0 654 4 524 4 366 7 265 5 1342 821 658 460 333 307 2093 1280 1026 717 519 4 79 2736 1674 1341 938 679 626 2326 1422 1140 50 00 40 00 40 00 2 38 1 82 1 4b 2 98 4 65 6 08 2 28 3 55 1 83 2 85 4 65 3 73 1 si Cycle 2nd Cycle 4 t ~' 5 6 20 0 024 30 00 20.00 3 47 1 47 1 85 2 88 3 77 506 1461 1348 797 577 532 1 36 170 2 66 15 130 0018 244 9 15 00 195 1 81 2 28 3 55 4 64 5 17 1 3 95 3 17 2 95 3 21 3 94 4642 0 156 136 171 267 349 691 ,V/k I Addis Aiiba in Association with r fd and AflCF Pt C 125 Detail Design of Bale Gadula Irrigation & Drainage Pioject October 2011Mini, uy ol Watei and Energy - I edetal Democi alic Republic of Ethiopia Table II 26 Scheduling Made for Block ! 26 in the BAGID Project Section- I. Volume - VIII Operation and Maintenance Manual No of Irrigalors/HH 3 No of Furrows Handled by a Farmer al Once 3 Total inflow at SC-1-2 (Hs) 0 131 TC* le vel dutyfl/ s/ha)= 12 TU Related Design Parameters Furrow Parameters TU Irngation lime by Soil Intake Families (days) No of Irrigation Days to Complete one TU (Days) Discharge of Off takingCha nnel(m3/s ec) 20 15 10 08 02 Total No of HHs In a TU 20 15 10 08 02 Categories of Cycles in the Rotation Name of SN off- taking Channel — length of TC in (m) AREA (ha) Furrow Spacing No Of Furrows 130 8 164 1 255 8 334 5 284 3 130 8 164 1 334 5 679 1 TU-1-26 1 663 - _______ 2 1U 1 26 2 948 3 TU-1 26 3 1078 4 TU 1 26 4 1685 5 1U-1 26 5 1518 6 TU-1 -26 6 1205 7 1U 1 26 7 671 10 30 40 40 0012 0 036 0 048 0 048 0 75 0 75 0 75 0 75 698 998 1000 30 00 4 48 255 8 6 98 9 13 1 70 1 45 2 13 1 82 3 33 4 35 3 70 2 27 2 84 2 84 4 43 3 71 5 80 3 15 4 93 40 25 0 048 0 030 0012 0 75 1768 2527 28/6 4493 4049 321 1 459 1 522 4 816 2 7 35 6 583 / 325 3 403 526 655 1024 923 628 898 1022 1596 1439 1142 636 821 1174 1336 2087 1881 1493 832 *i 3 57 1st Cycle 1135 1 774 1599 1269 40 00 40 00 40 00 2nd Cycle 2 04 2 56 4 00 5 23 4 44 0 75 3213 1790 732 408 25 00 2 59 3 25 5 07 6 63 5 64 10 0 75 707 3 61 4 53 7 07 9 24 7 86 1st Cycle 7769 195 0 234 I 10 00 195 - 17 22 34 44 rr J_______ iVWDSF Addis Ababa in Association with ICT Pvt I Id andABCE PLC Detail Design of Bale Gadula Irngation & Drainage Pioject October 2011Ministry of Water and Energy f • iferal Democratic Republic of Ethiopia Table II 27 Scheduling Made for Block-1 27 in the BAGID Project 1 3 No of Furrows Handled by a Farmer at Once □ No of Irtiijalors/HH 0 194 No of TCs level dutytl/s/haU 1U Related Design Parameters Furrow Parameters TU Irmjation lime oy Soil Intake Families (days) Total Irrigation Days to Complete one TU (Days) Discharge of Off lakingCha nnel(m3/s 10 08 Categories of Cycles in the Rotation LN Name of off taking Channel length of TC in (m) Furrow Spacing No Furrows 4 5 6 7 0 9 TU 1 27-4 TU 1 27-5 TU 1 27-6 TU 1 27 7 930 949 10 25 001? 0 030 20 40 0 024 0 048 TU 1 27 8 TU 1 27 9 695 1132 916 777 20 0 024 25 0 030 it;w f Addis Ahaba in Association with ,( 1 Pvt ltd and ABCE PL C Detail Design of Bale Gauula Irrigation & Drainage i inject October 2011Mini i} nt Watui and Fneigy ■ edeial_l emocidtic Republic of Ethiopia Section - / Vol line - V/// Operation and Maintenance Manual 10 W 1 27 10 636 11 TU 1 27 11 618 0018 0018 0 75 0 75 1695 1647 307 9 299 1 386 375 602 585 787 765 669 650 1500 15 00 2 28 2 22 2 86 2 78 4 46 4 33 5 83 4 96 5 67 4 82 11165 15 15 290 _________ 0 348 290 25 31 49 64 55 Table 11-28 Scheduling Made foi Block-1-28 in the BAGID Project No of IrngatoiS/HH 3 No of Furrows Handled by a Fanner al Once 3 Total inflow at SC 1 2 ' (l/s) 0 134 TCs level duty(l/s/ha)= 12 i 1U Irrigation 1 im s by Soil (daysj Intake Families 1U Related Design Parameters Fuiiow Parameters No of Irrigation Days to Complete one TU (Days) — Discharge of Off 201 15 10 08 02 20 15 10 08 Total 02 — Categories SN Name of off lading Channel length of TC in (m) AREA (ha) takingCha nnel(m3/s ec) Fuirow Spacing No of Furrows 1 130 8 164 1 255 8 334 5 284 3 No of HHs in a TU 130 8 164 1 255 8 334 5 679 of Cycles in the Rotation 1 TU 1 28 1 1830 60 0 072 0 75 4881 886 7 1112 1734 2267 1927 60 <X) 1 64 2 06 3 21 4 20 3 57 2 1U-1 28 2 1810 50 0 060 0 75 4828 877 0 1100 1715 2243 1906 50 00 1 95 2 45 3 81 4 98 4 24 1st Cycle 3 TU 1-28-3 1826 65 0 078 0 75 4870 884 7 1110 1730 2262 1923 65 00 1 51 1 90 2 96 3 87 3 29 4 1U 1 28 4 691 25 0 030 0 75 1844 334 9 420 655 856 728 25 00 1 49 1 87 2 91 3 81 3 24 2nd Cycle 6158 200 0 240 200 7 8 13 17 _______ 1 14 1 tWVDSF Addis Ababa in Association with IC7 Pv< Ltd andABCE PLC 128 Detail Design of Bale Gadula Irrigation & Drainage Project October 2011Minishy ol Wafer and Energy - I t. deial Dcmocralh Republic ol Ethiopia__________________________________ I able II 29 Scheduling Made for Block ! 29 in the BAGID Project Section - /. Volume - VIII Operation and Maintenance Manual No of Irrigators/HH No of Furrows Handled by a Farmer at Once 0 067 TC* level duty(l/s/ha)= 12 1 U Related Design Parameters Furrow Parameters TU liligation lune by boil Intake Families (days) No of Irrigation Days to Completo one TU (Days) 7 Discharge 20 15 10 08 02 Categories of Cycles in the Rotation Name of length of Off SN off aking of TC takingCha Channel in (m) AREA (ha) nnel(m3/s Fuirow Spacing Furrows 130 0 164 1 255 8 334 5 679 Til . 29 1 TU 1 29 2 TU 1 29 3 1 02 2 03 3 16 4 13 3 51 1 82 2 28 3S6 4 65 3 96 1st Cycle 2 86 3 58 5 59 7.31 6 21 2nd Cycle 6 8 12 16 14 Table -II 30 Scheduling Made for Block-1-30 in the BAGID Project No of Irngators/HH 3 No of Furrows Handled by a Farmer at Once 3 Total Inflow at SC-1-2 (Ms) 0 087 TCs level duty(l/*/ha) = 12 TU Related Design Parameters Furrow Parameters TU Irrigation Time by Soil Intake Families (days) Total No of HHs No of Irrigation Days to -. Categories of Cycles In the WWf • E Addis Ababa in Association with K T Pit Ltd and ABCE PLC 129- Detail Design of Bale Gadula Irngation & Drainage Project October 2011Ministry of Watei and Energy - I ederal Democratic Republic of Ethiopia Section - I, Volume - VIII Operation and Maintenance Manual in a TU Complete one IU (Days) Rotation 20 15 10 08 02 20 15 10 08 02 Name of SN off- taking Channel 1 1U 1 30 1 2 TU 1-30-2 3 1U-1 30 3 length of TC in (m) AREA (ha) Discharge of Off takingCha nnel(m3/s ec) Furrow Spacing No of Furrows 130 8 164 1 255 0 334 5 284 3 130 8 164 1 255 8 334 5 679 928 1223 1190 35 0 042 0 060 0 054 0 75 0 75 0 75 2475 3261 3174 449 L 592 5 57b 6 564 743 723 8 79 1159 1128 >150 1515 1475 977 1288 1253 35 00 1 43 1 79 2 79 3 65 3 10 50 45 50 00 45 00 1 32 1 65 2 57 1st Cycle 2nd Cycle 1 42 1 79 2 78 3 37 3 64 2 86 3 09 1st Cycle 3341 130 0 156 *i 130 4 5 8 11 9 l^WDSL Addis Ababa in Association with ICT Pvt Ltd and ABCE PLC -130- Detail Design of Bale Gadula Irrigation & Drainage Pioject October 2011Ministiy of Wale/ and Energy I ederal Democratic Republic of Ethiopia Appendix IIIFormat of Water Delivery in each canal Section - /. Volume - VIII Operation and Maintenance Manual For Secondary and 1 ciliary Off taking Points Only Name of Off taking Canal Parent Canal , Authorized Discharge at Head Full supply depth at headFull supply depth at tail I Date Start time Hr minutes I nd tune Hr minutes Total time minutes Gauge al head m 5 Discharge in m’/s Volume (if water delivered m' Gauge al lail with start time Hr minutes 8 Gauge al lail with end time Hr minutes 9 lotal time in minutes Discharge in m3/s Volume of water delivered m3 12 3 4 6 7 10 11 Signature of recorder gauge reader/ water controller 12 / I i A'ldi't Al> iba in Association w/f/i /< t P,i I id andABCE PLC Detail Design of Bale Gadula hngation <£ p. j j h/< / October 2011Ministry of Water and Energy - Federal Democratic Republic of Ethiopia REFERENCE A M Michael (1978) Irrigation Theory and Practices Section - I, Volume - VIII Operation and Maintenance Manual Y C Lim etal 91981): Hydraulic Design Practice of Canal Structures ME Jensen (1983) Design and Operation of Irrigation System Richard H Cuenca (1989) Irrigation System design An Engineering Approach FAO Irrigation & Drainage Paper No 40 (1982) Organization Operation and Maintenance of Irrigation Schemes FAO Irrigation & Drainage Paper No-56 (1990); Crop water Requirement Estimations K Subramanya (1997): Flows in Open Channels Southampton University IIS (1990-91) Lecture Note for MSC program in Irrigation Engineering Chow V.T. (1983) Open channel Hydraulics N B WebDer (1971) Fluid Mecnamcs for Civil engineers; M G Boss (1989). ILRI Publication 20 Discharge Measurement Structures PN Modi ( ) Irrigation Water Resources and Water Power Engineering. P Novak etal (2001) Hydraulic Structures (Third edition); VWVDSE Addis Aoaba in Association witn ICT Pvt Lt~l and ABCE pLC ■ 132- Detail Design of Bale Gaaula Imgation & Drainage Project October 2011R RI R W I I I I I I I I I
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