Ministry of Water, Imgation and Electricity Addis Ababa
Ethiopia
Dabus  irrigation Development Feasibility  Study  and Detail Design Project
Volume VII
Final Operation, Maintenance and Safety Manual
Part II
irrigation and Drainage System
April, 2016
Water Works Design and Supervision Enterprise
P.O. Box 2561
Tel * 251 11 661 45 01
Fax + 251 11 661 08 98 Email w w d.s e@ethione et Bob Mariey Avenue
Addis AbabaMinistry of Wafer, Irrigation and ttactncty 
Vow- VII -Final Operation. Maintenance and Safety Manual
Clot!rrjg-ai onStudy and Design Proved_______________________________ Pam II- Irrigation and Oroinage System
Dabus Irrigation Development Feasibility Study and Detail Design Project
Volume VII
Final Operation, Maintenance Safety Manual
Part II
Irrigation and Drainage System
April, 2016
Issue and Revision Record
Issue
Date
Originator
Tb s  document has  been prepared for the tiled project or named part thereat and should not be relied upon or usea far any  other project without an independent check  being earned out as  to its  suitability and prior written authority  af Client being obtained WWDSE accepts  no responsibly  or liability  for lhe cansequence of this  document being used for a purpose other than the purposes  for w^ich it was comm *ss.on cd Ary  person using or relying or '.he document for such other purpose agrees  and w H by  such use or reliance be 1a<en to confirm his  agreement to indemnify  WWDSE for al loss  or damage resulting there from VUWDSF accepts  no responsibility  Dr liahi ily  for this  document Lu any party other than the oerson by whom it was com missioned
*Afa!c" Wdfo 3f.sigr and
AnnI 20 ’6Ministry of Water, Irrigation and ElectHoty 
Vnrume- Vll rinai Operation. Maintenance and Safety Manual
OatiidS Irrigation Study antj Design ruqect____________ ______________________Parrt II- Irrigation and Drainage System
DETAIL DESIGN OF DABUS IRRIGATION PROJECT DETAIL DESIGN
SECTION 1
VOI UME - 1 VOLUME-II VOLUME-ill VOLUME ■ IV VOLUME - V
Parti
LIST OF THE VOLUMES
DESIGN REPORTS
Executive Summary
Design of Dam and Appurtenant Structures Structural and Electro-Mechanic al Design of Dam Design of Irrigation and Drainage System
RAP and Design of infrastructures
RAP
Part 11
Design of Infrastructures
VOLUME -VI
Engineering Cost Estimates
f VOLUME-VII ■■
-,H- J   Operation, Matntenance.andVSa'fetv Manual
Dam & Appurtenant Structures
ig ano n.'at  urainajge Sys te mi ,
1
JI 5
i
£*i'
7*
—?
SECTION II
TENDER DOCUMENTS
VOLUME-VIII
Bid Document
Part l
Cam and Appurtenant Structures 
Part II
Irrigation and Drainage System
VOLUME IX
Engineering Design Drawings 
Part I
Dam and Appurtenant Structures 
Part II
Irrigation and Drainage System
Part III
Infrastructures
VOI UML - X
Technical Specificat'or.s
Part I
Dam and Aopurtenant Structures 
Part II
Irrigation and Drainage System
7.'a:e Warxs Des c" aid
r
ii
2316M nistry af WnJflf, irrigation and Efectncty Dacui rr gatian Study and Design Project
Volume- VII -Fina Operation. Maintenance arw Safely Manual Par*! II- Irrigation and Dra.rage Sysicn
TABLE OF CONTENTS
TA0I F OF CONTENTS
LIST OF TABLES.. .
LIST OF FIGURES
ACRONYMS AND ABBREVIATIONS
EXECUTIVE SUMMARY
1 INTRODUCTION ...
Purposes of Operation and Maintenance (O&M) Activities ...
iii
. VI
... vl
. vii be
1
.. . . 1
1 2 Objectives. .
DISCRIPTION OF THE PROJECT........
....................... -......... ............................. ............................... 1
2
■ - • -- • --     --■» rHri
3
2 1. Project Location.......................... .... 2 2         Topography and Agro-Climate 2.3         Project Features 
3 Crop Water Requirement.
.............................................. r....... ............ ,,............. .................. 3
........................... . 3
................ ............. .. ........................ . ............................ .3
4
31
32
33
34 3.5.
35 37 38 3.9 3.ID 3 11
Generg; .................... ............................................. Climate Data and Reference Crop Evapotransp-ralion
■■
RamFall Dala
............... ..........................................
So> Data ................................................................ .................... ........ .
Crop Data .............................w.„............ ...................
Cropping Pattern .....................................
Estimation   of   Crop   wafer   and   Irrigation   water   requircrncn! rngal on Efficiencies, Duty and Operation Hour
Peak Duty nf Canal System ....................... ...................... ..............
Irrigation nterval.................... ....................... . . ...........................
Sizing of Trigatron L’nrt....,................*.................................. .............. .
...4
4
4 5
11 III
-•
6
7
8
11
11
12
I
•............. • • 11 ■ i .
■ iii ■ n- i i - -
t
,■.
4          DESCRIPTION OF IRRIGATION AND DRAINAGE SYSTEMS
-r- r-ra« i
12
14
4   1 General
...     ... .
...... ... ,M................................................................ 14
4.2.        Canatsnetworks.................... .................... ..................................................................... .... ,         ................. .16
4   3 Canals and drainage structures 
...
Tabic 4 4 Canal structures detail of the project.................
4               4 Flexible Gated pipes (Flexi flume)............ ................ . ...
................. ................... 18
...... , ,20
44 1 General . . .................................. ..
..............,14.................................. . . ........................ ..................20
4.4.2.          Lise ol Flexible Gated pipes (Flexi flume) .. ............................... ... 4               4 3            The Role of Ffexi flume m improving Productivity ....
.. .
...........21
.........21
444              Design parameters of FGP                 ................................................................................................    22
4               4 5            Components of FGP
4 46 Installation procedure of FGP .
24
..24
4 5 Nrghl Storage Reservoir
4.6 Hydro Mechanical Gates ... ....
............ ............................................................. ................. .... 26
........................................ ....
t
27
5      IRRIGATION SYSTEM OPERATION PLAN .......................................................................................29
5 1 General
.............. ......... ir.............................................................. ...................... ........ 2B
5               2               Operational               Plan in      Main Canal ...
5               3               Operational               Plan in      Secondary Cana1
5               4               Operational               Plan m      Tertiary Canal
5.5 Operational Plan in Flexi Flumes.......................... ........... . . ..................... ...
.....
29
29
29
30
5               6               Operation and management of FGP (Flexi flurre} for irrigating a field ........................................ 30
5.7          Operational plan of Gates ...................... .............................................................................................. 31
5B Operational plan of Outlets...................................
....
32
•Ar m W£f<s Dcsigr and
April, 231 6Ministry nl Waler Irnga! on ard Electricity Dabus Irrgatpn Study a^d Des cn Project
Volume VII-H^aI Operation, Maintenance and Safely Manila Pamfr Irrigation and Dra.^age System
6.       iNSEPECTION WORK OF CANALS AND DRAINAGE SI RUCTURES................................... 33
6    1 General,. ............................................. ........... ............ ........*---------- .... ...*...........
6.2          inspections □'Carals.................. ......... ........... ................ ... ...................... ......
6.3         inspection of Canal Head Regulator....... ............. ........................... .................
6.4         Inspection of cross drainage works ....................... ...........-............... ..............
6.5         Performance of Structure .......................... . . ............ ....................................... fi.5 Flow Rate Measurement Dev-ccs. Methods and Regulators
6               6 1 General ...
■■ -        ■ >•       ........
6.6.2    Auxiliary Equipment and structures for Measuring Flow............................
6               6.3            Methodology
6.6.4           F'ow Measurement     in Turn Out
6 6.5, Flow Measurement in Regulator
........
6               6 6. Rating curve .
....
...... ........................................
6               6 7. Discharge Regulating and Controlling Canal Structures....................
33
33
34 34
35
36
... 36
.......... 36
........... 37
.......... 37
.......... 37
. 38
7,        MAINTENANCE OF THE IRRIGATION & DRAINAGE SYSTEMS.,....... ........................... 39
7 1         General........... .. ............................
7 2         Categories of Ma-ntenance
7 3         Maintenance Activities....
7               3 1 Bed and Berm .......
7               3 2            Escapes,.,.........
7               3 3            Silt Clearance
7 4 Maintenance of Embankment
74 1 Banks....................................... . .....
........ .......................................................  39
.............................................................. ...40
42
................................................................  42
............... .
............................ 43
.................................43
........... ............ -........ ..................... 45
7 5         Vegetation Growth
........................................
................................
76
Roads and Ramos 
.......... ....................... ........................ . ..
... .
7 7         Maintenance o? Furrows 
............ . .......... ..........................................
7.3         Maintenance/Repair of Aexi flume
.....
..............
7 9         Maintenance of Earthen Can ail
...
.............. ................ .............................. ....
7 10       Maintenance of Structure                ..
.............. ...................................... .
..
7.10 1. General ........................... . ..
7.1Q2 Maintenance of Lined Portions of Canals 
........ ................................................ . .... ........... . 4B
....................... . ..
7.1 D 3       Damages, remedial measures & maintenance of cross drainage structures.
51
52
7.1D4 Regulations 
........... ................. . ........... .................. ......................_........ ..... ............. 54
7 ID 5        Outlets................................................... ...........................................................................................55
7 11 Maintenance of Hydro-Me chari cal Installations .. ............................... ................... 55
7.11  1      Protection and maintenance worfcs of gates ......................................... ......................... 55
7 12. Maintenance of Drainage Syslems.............................
. .................................. ...... 57
7.12.1         Structures on drains ......................... .................................................. _............ ....................... .57
7.12.2         Drams Maintenance................................................... ..................................... . . ........................... 58
7.13. Sources of Materials for Repair ..
........ ......... ........................................... ..................... . ......... sb
7 14 Personnel Need for Maintenance ............................ ..
8. PROJECT ORGANIZATION AND MANAGEMENT
........... ...... .... ......... 59
... 60
0 1. General............................ .............. ............ .................................... .......................... . ......................... .......... 6C
3 2        Establishment of Dabus Irrigation Development Enterprise ,. ........................... ....................... ............ .60
3 3 Objective □! Daous Irrigation Development Enterprise ............................................................... ... B 4       Proposed Organizational Structure for Dabus Irrigation Development Enterprise . ... . 60
3 5        Responsibilities of Dabus irrigation Development Enterprise 36 Responsibilities of Waler Users .. ..................................... ...... ..
...
... 60 61
.......... ..................... 62
0 7         Responsibility of Operation Department.................................................................................................   62
9  8      Responsibility o’Maintenance Department ............................ . ........... .. .............................. ... . ...............62
B.9        Responsibility o* Water Users Associations.....................................................................................         63
3.10      Infrastructure Management................................................................................................................        53.
3 11 Management of maintenance activities 
...
...
0 12. Management Task 
....................... ............................................ ........ . .
63 ...64
9, EQUIPMENT REQUIRED FOR MAINTENANCE AND DPF RATION ........... . ..........        rrv rn 1 1* - a       ... 65
9 1 Genera-
....... ..
............. . .................................. ................ .
9 2 Machinery 'or Maintenance Embankment and Side Stopes . Wa'.C’ W: <5 Design are
.
....
55
65
r
April. 2016Min miry 0* waler Irrigation and Eteclhcty 
Volume- VII -Aral Operation Maintenance and Safely Manual
Dabus Irrigation Study and Design Project _______ _______ 9 3              Machinery (or Control af Grasses and Weeds 
_______ Pyrt lb Irrigation and Drainage System
65
9.4.         Machinery    for Maintenance of Flood Protection Embankments                and River Course             ..     55
9.5.         Mach'nary    and Equipment reduced ..................... ....................................................................................   66
10       MAN POWER REQUIRED FOR OPERATION AND MAINTENANCE .......................................... 67
10.1. General............................. _..... .............. ........ ..................... .
10 2 Job Description of Various Staff Required for Operation A Maintenance
10 2 1 Project Manager................................. ...................................... ........................ ...................■
67
68
..........68
10 2 2         Maintenance Engineer. Irrigation/ Civil             and His Teams .........................................................  68
10.2.3   Mechanical Engineer ,>..................... .................. ............................................................ ......................— 68
10 2 4         Mechanical Foreman.............................................................................................................................. 68
10 2 5 Water Management Engineer............ ............................................................................................... 58
10 2 6 Monitoring Technicians on Groundwater 10 2 7. Irrigation Assistants 
10 2 8 Gate Operators of Head works 
................. ...
.................................. .......................... 69
................. . ........... . ............................... —. 69
69
10 2 9 Gate Operators for Head Regulator......................................... .............................................. ......................70
10.2.10. Gale Operator for outlet .................................................. -................... ........................ ...................... 7Q
10 2.11. Other gates 
..... .. .......... . .......................... ........................ ................... ........ .................... 71
10 2 12. Water Guards ........................................................ ............................................... ......................................71
10 2 13. Surveyors........................... ............................................. ...................................... . ............................ .71
11.          COMMUNICATION SYSTEM ...
111 General...................... , ....... ......................... .......................................... ....................................... ............. . 72
11 2 RelaVonship of Irrigation Agencies <md Water Users Association
......................... 72
12. TRAINING..................................... . ..................................... ........................... ...... ,........ .......................73
12  1 Train ng of Farmers 
. ............. .................................. ................................... ... ................ ......,73
12 2 Training for Farmers Reoresertalives...................... ......................... ....................................... ............................. 73
12 3       Traming of Trainees 
,, ................................................ ......... ............................................ ..74
12.4 Iraming Fo'Members of Water Users Associations (WIJA) ......................................... . 75
REFERENCES
ANNEXS
76
WatC’ Works Design inc
V
Apri zCifiMinistry til Waler, Irrigation and Eleclwly 
Vo urre- VJ -Final Operation, Ma-ntenanci? and Safely Manual
DaDus irrigakDr Study and Design PreFee!_________________________ Pant II- irrigation and Drainage System
List of Tables
Taele 3 1; Climate data and estimated ETO
Table 3 2: Mean Monthly Ram-faH and Elective Rain fall Data .
Table 3 3 Crop Coaffident [Ke] Values of different crops 
Table 3 4 Cropping pattern aflhe project area .............. .............................................. Fable 3.5 Net Irrigation Requirements (NIR) of Dabus Irrigation project...
Table 3.6: Dabus Irrigation Project Command Irrigation Scheme supply... Table 37 Inlerded Irrigation Efficiency Duly and Operation Hour
Tabfe 3 9 Doak Design Duly of Canals -
Table 3 9 irrigation Interval..
,
. ...
Table   4   1   Geo-membrane   lining   reaches  and   roughness  coefficienl   o'   Mam   carats 
-4-* — ir
Table 4 2: Hydraulic Calculations of Main Canals Table 4 3: Canal structures detail of the project Table 4. 4: Canal structures detail of the project..
...
Tabled 5: Relation between ftexi flume cu’Jet discharge’Q" and pressure head h'
Table 4 5 Capacity of Night Storage ?onds 
Table 4 7 Steel Work! Hydro mechanical Gates within the proiect
...
Table 9 1 Required Machinery and Equipment of lhe project ..................................... ..................... Table 1C 1 Manpower Requirement of Operation and Maintenance work . .
• •
67
LIST oF Figures
Figure 4 1 Layout of Irrigation ana Drainage system of Dabus farm Irrigation Project ..................................... . ... 15
Figure 4.2 Flexi flume Outlet Installation and Removal procedures 
Figure 77 Fluming repair methods 
.................... .
...
.............................. 47
Figure 8 1 Dabus Irrigation Development Fnterpnse Organira! an Structure
25
61
Walr Works Des ;■* and
r
v
Anri I. 7016Ministry c* Water irriqjton and Electricity Iflrigailgri Study and Design Prp.ect
Volume- VI i -Fima Ooe.'at'on, Maintenance a rd Safety Ma-nua __ _______ ________ Pant <h Irrigalien and Drainage System
ACRONYMS AND ABBREVIATIONS
O& M WUA
m a s.L CA
CCA GCA NIA
Ha cumec
FSL
L RMC RBMC NSR/NSP Hrs 
"nH PC SC’s TC’s 
□Os ID's h
OT Q
Yi
0
Ctf
8
W Or Hr LSIP l/s
IS WMC
Operation and Maintenance
Water User Association
Meter above sea level
Command Area
Cultivable Commanded Area
Gross Command Area
Net Irrigation Area
hectare
Cubic meter per second
Full Supply Level
Left Bank Mam canal
Right Bank Wain Canal
Night Storage Reservoif/N:ght Storage Pond Hours
Manning’s Coefficient
Primary Canal
Secondary Canals
Tertiary Canals
Quaternary Canal's
Interceptor Drains
Water level head
Off Take
Discharge
Entrance water depth above the sill or floor Width of the gate
Coefficient of discharge Gravitational acceleration
The opening of the vert cal gate Gruss regulator
Head regulator
Large Scale Irrigation Project Liter per second
International Standard
Water Management CommitteeM nutry of Wa:er  Irriga: an and Efectncily Dau us lrrtga!ion Study Desg^ Project
VglLrrc VII-Fina Operation Ma ntenancje and Safely Manual Parrt il Irrigation and Drainage System
°C
HFL
FAO PMU
l/s/ha
mm/day
mm/month
Degree Centigrade
High Flood Levet
Food and Agriculture Organization Project Management Unit
liter per second per hectare millimeter per day 
millimeter per month
IS
International Standard
R/M
Reoair/Maintenance
FGP
Flex bfe Gated Pipe
MCM
Million Cubic Meter
WWSOE
Water Works Study and Design Enterprise
GIWR
Gross Imgation Water Requirement
FTo
Evapotranspiration
TAM
Total Available Moisbre
BGAB
Benshangul Gumz Agriculture Bureau
□IDF
Dabus Irrigation Development Enterprise
PIM
Participatory Irrigation Management
Wale Wcrxs 1 Jesign a"d
r
v III
AitnE. ?C'GMinistry of Water. Ir gjition and E ectricHy Dabus Irrigation Study ana Dosign Project
EXECUTIVE SUMMARY
Volume- VII -F nji Ope'abcn, Ma-Penance ana Safely Mar.ua ____ _______ Par ft lb Irhgalajn and Drainage System
Dabus arge scale irrigation project is located in Bonishangul Gumz Natinnai Regional State. Menge and Oda Biidiglu Waredas The Project is about 725 km from Adars Ababa and 55 Km east of Asosa (the capital) with geographic coordinates 10*02' to 10' K Northing and 34 ‘ 51' to 35* 02’ Easting and an altitudes ranging from B50 to 1 JOOmasI
The scope of this project is to develop irrigation scheme that would contribute in increasing optimum agricultural production and productivrty  among beneficiary  farmers  in irrigation development areas
The mam objective of this report is to discuss about operation, maintenance and genera! feature of Dabus irrigation project Based on the detaied layout of irrigation and drainage system, the command area of the project Iles on the right and left bank of the Dabus River with total Net Irngable Area (NIA) of 9100 ha Water from the source to the distribution systems conveyed through both left and right side main canals. Both LBMC and RBMC of the project designed to convey a 'low of 1 40l/s/ha for 24 hour irrigation period a! peak season. Operational hours of secondary canals off-taking directly from the main canals are 12 hours and off-taking from Night Storage Ponds are 12 hours with canal duty of 2.33ls/ha. Similarly, operational hours  for tertiary  canals  off-taking from Secondary  canals  aligned before and after night storages are 12 hours with canal duty of 2 15 l/s/ha. Quaternary canal of this project is Ffexi Hume type of canals designed to convey 401/s irrigating 4.3 ha/day and completing 60 ha within 14 days rngation interval Night storage ponds ace planned to store water how for 12 hours during night when all the rest of canals and outlets shall remain closed
The performance of the irrigation and drainage system of the project is based on both effective operalion and maintenance activities. Irrigation system operation is activities to provide farmers with water when they need it and in the quantity required for crop waler I irrigation requirement. The maximum irrigator, requirement of Dabus large scale irrigation project assuming overall irrigation efficiency of 50% and 10% flexibility factor, is 153.05 mrn in the month of February
The irrigation operation plan describes the allocation and distribution of (he available waler from the off-taking point at lhe head work to secondary blocks, tertiary units and field canals.
• cnab'es fanners to formulate operation schedule, the contact duration in irrigation, and to monitor water loses Maintenance, on the olher hand, is a regular repair to ensure system operation of the project satisfactorily. Its purpose is to apply the technical aspects of
ensuring that the physical infrastructure remains in good physical condition
Periodica inspection of canals  and appurtenant structures  is  necessary  to ensure the adequacy of the structures to serve lhe purpose for which they were designed, to verify the conditions of the structures and monitor their behavior, to investigate conditions that might cause distress so the structures and to study the extent o deterioration based on which
f
maintenance  and  repairs  can  be  planned  especially  oefore  and  after  rainy  season  to asce da inf examine their condition and functioning.
Waterworks Drsg and
r
IT
Anri 7316Mirittry Qf Waler I rig a linn .^nd Elects city 
Vo-’i/me VII-Finai OoergXjn, Maintenance ana Safety Manua
Paces irrlgaljort Siudy and Q&sign Project_______ _____  _________  _____  Parrt JI- frrrgation and Drainage System
The operation and maintenance of large scale irrigation scheme is beyond the capability of farmers. Tnerefore, the applicable organizat'onal arrangement of this  project is  dual managed system. Under dual-managed system the scheme is divided in to two which can be managed by  the Operation and Maintenance (O & M) Agency  i.e Dabus  Irrigation Development Enterprise (DIDE) and Water User Association (WUA) It is  quite imperative that different group of manpower amongst I he O & M agency  are formed who wit! be associated with different tasks so as to have in depth knowledge of the functions and the utility of the scheme.
The operation and maintenance of the head work, appurtenant works, infrastructures, on farm development and drasnage system need knowledge, systematic  approach constant devotion as  well as  good communication system Io utilize the services  successfully  and sustain the scheme for a longer period of time
Waler Wc *s Dcsigr
r
ftp'1 201RMinistry of Water, IfflgaSan aria ElcctfiOly Dabus 'rriga^cn Study and Des gn Project
1.       INTRODUCTION
Volunr-o Vrl *al Operation, Marte’lance and Safety Man-ja Parr II- ImgaLon ard Drainage Sys to n
1.1.    Purposes of Operation and Maintenance (O&NI) Activities
The purpose of operation and maintenance (O&M) is to enable the irrigation system to functron at its maximum capacity to meet the requirement at the quatcrnary/fiekl canal off takes without undue constraint so that good crop yields can be achieved
Both epe^abun and maintenance are concerned with the performance of the irrigation and dramage system but their objectives are different;
irrigation system operation is io provide farmers with water when they need il and in lhe quantity required for crop water / irrigation requirement. Although the calculation of the delivery of the quantity of water through irrigation scheme of canals and structures and its scheduling cf delivery is calculated using engineering technical formula and methodology
Maintenance, on the other hand, is a regular repair to ensure system operation satistectar iy Ils purpose is to apply the technical aspects of ensuring that the physical infrastructure remains in good physical condition so that the delivery of water (ooeration) is maintained at the level o' efficiency wtnch enables.
(i)        Equally of delivery,
(ii)       Timeliness of delivery and
(iii)       Correct  and  adequate  quantity  delivered  to  all  farmers  in  accordance  with  the agricultural and crop requirements.
Regular maintenance of the irrigation system reduces repair costs, help the system las! longer, and keep irrigation efficiency al design levels. Efficient waler use requires simple, but ongoing maintenance
Life spar oT irrigation system is determined by quatity of the construction originally instated and the ongoing operation and maintenances of the system. The operation and maintenance work need knowledge, systematic approach, and constant devotion to utilize the services successfully and sustain lhe scheme for a longer period of bme
i his manual explains what it takes to make an irrigation scheme function, and how to keen t functioning.  Therefore,  it  provides  information  on  the  principles  of  the  operation  and maintenance.  However,  for  detailed  information il  is  required to  refer  (he  irrigation and drainage design report of Dabus Project
1.2.   Objectives
rhe operation and maintenance manual document s prepared at design level Df the irrigation scheme Preparing a practical manual for irrigation users provide useful information
about the design and give an advice how 1 should perform. The mam objective of this manual is to explain about operation. maintenance and general feature of an irrigation
□raject The manual gives mainly how to organize lhe users while they involve n operation
Waterworks l>5?":                                                                1
Aprl, 2316M.nlatry of Water, I'rngaticm and Electricity                        Vo’.-me- Mil -Finaf Oceraiion Maintenance and Safely Manual Dabus IrriflaiMXT Study and Des gn Project _________  _____ _ __  ________ Parr; II Irrigation and Drainage System
and maintenance of thefr project, how to measure flow rate to ensure equitable water distribution and to minimize water losses  It provides  procedures  for operating and maintaining the system for proper functioning, provid'ng information regarding periodic inspections and prompt repair or reolacement of damaged components of the system from the main intake to the field Thus the user will have sufficient information about their project and how it could serve longer without any problem through undertaking various maintenance procedures
Water Wonts D»gn anfl
11nnnrinr P R<A.*Ar » a
i
An- ?Q16M ristry of Water. legation and Electricity 
□anus I rig a I ioh Study and Design Project
2.         DISCRIPTION OF THE PROJECT 2.1.      Project l ocation
Volume-V F rial Operation. Mamie nance and Sa 'ety Manual Pa71 II- Irrigation and Drainage System
Dabus  Irrigation and drainage? development project command is  located in Benishangul Gumz National Regional Stale al about 55 km east o* Asosa (the capital) and and 725 km from Addis Ababa The command area of the project lies on the right and left bank of the Dabus Riven which is the boundary of the two project weredas; Menge and Oda Biidiglu. The project area is part of Abay River Basin with geographic coordinates of 10*02' to W14' Northing and 34* 5 T to 35 D2‘ Fasting between altitudes of 850 to 1,100 mast.
2.2 Topography and Agro-Climate
Topography is one of the factors that affect agricultural development The topography of the project area is mainly plain and undulating land. According to the survey data the elevation range between 850 and 1100 masl and the slope range between 0% and 8%, there are also places with slope greater than 8% around the command area.
Based  on  the  Ministry  of  Agriculture  (MoA)  classification  of  the  agroecology,  all  of  the command area is charactenzed as kola This is due to the area has the characteristics of altitude below 1,500 masl with average temperature range from 20'C                 40’C and rainy season  spreads  through  May  to  October  The  rainfall  distribution  is  mono-modal  and  the annual rainfall rarges from 750-1500 mm
2.3.     Project Features
Dabus large scale irrigation project ma nly consists of
•    Head work (Diversion dam structure)
•    Mam Canals
•    Primary Canals
•    Night storage reservoirs.
•    Syphon structures.
•    Escape structures
•    Cross Regulator structures
•    Head Regulator structure.
•    Cross Drainage Structures.
•    Secondary Canals, Tertiary Canals with associated drop structures, and off Sakes.
•    Chamber structures especially for flexi flume, which replaced quaternary cr field canals
■ Interceptor Dram and associated overfall slruclures
•    Tertiary drains and associated structures
•    Drain Drops ana outfalls
•    Service roads.
f
•    On-farm wo^ks consisting o erosion control and protection structures
3
April. 2Q t6Minrslry of Waler, Irrlgalon and Electricity OaCuS Irrigation Study a ng Design Prcij&c:
3.       Crop Water Requirement 3.1.    General
Vo'uTie- VII -F:ral Opera’, on Maintenance and Safety Mani;a
____            Para It- Irrigation a no Drain ag d System
Estimation of Crop Water Requirement (CWR) is essential for planning srrrgation water and adjusting water duty and thereby increasing Ihe yietd of the irrigated crop
3.2.    Climate Data and Reference Crop Evapotranspiration
Reference crop evapotranspiration (ETd) has been estimated using Ihe CROPWAT ver 6 program supplied by EAO. with irrigation and drainage paper 46 (FAO. 1992). The climate data used for the denvation of ET© in the command area nas been transferred from Assosa the nearest meleorolog’cal station to the command area (using the regional monthly climate data and altitudinal factors). The summery of Climatic data and the resulting ETo values arc provided in Table 3.1 below:
Table 3.1: Climate data and estimated ETO
r
Country Ethiopia
Altitude lOOOmasf
Latitude 10.02* N
Station Assosa (command area)
Longitude’34.50: E
tempera Lire
(°C)
RH
(%)
Wind
speed
Sun-shine
hours
Solar
rad la Iran
ET,
(mm/day)
Month
(fcm/day)
(MJ/m’rtay)
Min
Max.
i
January
16.6
34 1
60
189
84
19 7
5.D9
February
17 6
35.8
55 •
196
a2
20 7
5.72
March
18 a
37 4
58
163
75
20.8
5.69
April
19 5
37 1 |
61
138
6.0
18 8
5 1fl
May
19 2
32.4 |
70
131
5.5
17 7
4 33
■ June
18 5
29 8
at
131
5.0
16.5
371
i July
18 2
27 9
82
104
45
15 9
3.38
August
17 9
28 1
BO
89
5.0
17.1
3 54
September
17.9
29.3
81
87
IB 1
3 72
October
17,9
30.9
! 76
84
6.8
18 9
391
November
1B0
33.4
68
94
B.3
19 7
4.27
December
17 1
33 7
56
163
B6
19 4
4 90
Avorage
18.1
32.5
69
131
6.6
18.6
4 46
Source Dabui Imgitbon project. Agronomy report <201 <)
The adacted reference crop evapotranspiration (ETa) of the project are:
The Average ETo - 4 46 mm/day
Max mum Flo - 5.72 mm/day in the month of February
Minimum ETo = 3.38 mm/day in the month of July
3.3.    Rainfall Data
The effective ramfall, from mean annual rainfall of the transferred data from Assosa the nearest meteoroogcal station was estimated oy selecting the USDA S.C.S method torn the list of choices given in the program (Dabus Hydrologca’ study report, 20*4) The USDA S.C method used tc estimate effective rainfall is given as;
Waler War*? Design one
*4*.. .mimiFI ^•■••cwiiro
4
Anti 1.2016
•
IMinify n( Wai*” I rdgabon antf Electricity 
VoFurrc VII-Final Oscral cn Maintenance a.-xj Safety Manual
Dat^s Irrigation Study and Dcs;cn P^ect ________________ _____________Part II- Irrigation and Primage System
P,.. -= (p > <125-0.2 x.i ■< pYl. 125 ferr P £ — ;nr,i fl
3.1
= ***’■ a + 0.1 X p for P > c npf Where,
/ Pe- effective ra.nfall in mm, J P:- rainfall in mm and
Equation
................        ................ Equation 3.2
z a - a temporal resolution correction factor and was taken to be 3 for monthly values. The estimated PrfT is shown in T able 3 2 below:
Fable 3.2: Mean Monthly Rain-fail and Effective Ram fad Data
Country
Ethiopia
Station: Extrapolated Aso
sa Station Data
Allitudc 
1000 masl
Latitude: 1
0 02° N Longitude. 34.50° E
Rain-fall________
J_______ Effective Rain-fa
ll___________ I
Month
mm/month
mm/day
mm/menth
mm/day
January
0 40
D01
0 40
001
February
3.60
0 13
3 60
013
March
18 00
0 50
17.50
0 56
April
20,00
0.67
19.40
065
May
58 00
1 87
52 60
1.70
June
i
177.00
5.90
126.90
4 23
July                          247 00                      7 97                        14940                        4 02
j
August
238.00
7.68
147.40
i
4.75
September
211 00
7 03
139 80
4,66
October
60 00
1 94
54.20
1,75
November
7.00
0.23
6.90
0 23
December
2 00
0,06
2.00
0.06
Average
86.83
2.84
60,01
1.96
Source - Dabus irrigation project. Agronomy report (2014)
The total amount or annual effective rainfall within the project a ea is about 720mm, but 93% of il (670mm) is received during the wet months (May October) The dry season (November
F
April) orly gets 49 8mm P  that
er
indicates the need for irrigation during this perrod.
3.4.    Soil Data
The soil parameters important for calculating the irrigation scheduling and for this study we have selected clay soil wmcri is the dominant soil of the project area, But in the actual calculations of scheduling noth heavy and medium textured soil types will be considered
Waler WorXS Design ana
5M-n stry o'Wate', Irrigation ana E eetrioty Daft us imga^on Study and Design Project
VdIutid-Vll -Frnal Opera I inn. Maintenance ancf Safety Manual
____
^arrt It- Irrigation arid Drainage System
based on the results of both physical and chemical characteristics of the soils of the project area The effective depth of these soils area is in range of deep lo very deep (>150cm) The available water holding capacity (AWC) of the sails ranges from law to high within the top 100 cm layer The wider range of AWC (low to high) m the study area is related to textural variation. It ranges from 16-6 to 216 04 rnrrtfm
The optimum infiltration rate of the soils in the Project Command ranges from 5 4 ern/hr [suitable for surface irrigation] lo 9 6 cm/hr (marginally  suitable for surface irngation-too rapid) The hydraulic conductivity of the soils ranges from 0 50 to 1 08 m/day (moderately slow) The average infiltration and hydraulic  conductivity  values  of the soils  appear to be acceptable with various degree of suitability
3.5,   Crop Data
The choice of a crop for a particular area under irrigated and/or ram fed agro-ecosystem is mainly dependent on national needs. Regional needs, soil suitabilty and climatic suitaoility Crop response to irrigation, the existing socio-economic  situation, marketability  and expected profitability  are also influential crop selection criteria The climatic  parameters determining the choice of a crop are temperature, sunshine, wind speed relative humidly and precioitation. Like climatic  factors, the physical, chemical and biological characters  of soil and soil depth also have direct influence on the performance of a crop
Besides the above factors, the present land use, social reflections. Iilkicg of the farmers, Their attitude and ability to successfully cultivate a particular crop also determine the choice of a crop and cropping pattern
Crop data is  one af the basic  inputs  for estimation of crop waler requirements  for the different crops. The most important crop data required are the crop coefficient (Kg), rooting depth and canopy cover values at different growth stages, as well as the length of growth stages
The basic crop data values used for estimation the irrigation water requirements of selected craps  (Teff, Mave Haricot bean Rice Sweet potato, Noug. Sesame, Ginger, Black  cumin, Onion. Garlic. -’eppe . Fruit, Forage crops) are briefed under the following table 3 3 below
r
6
Acr 2211)Minrstry or Waler* Irrigation iW Flcclnaly 
Volume- Vl>‘ -Final Operation, Ma ntenance ana Salely Manual
Dato-s Jfr gal on Study and Design Project               ______ ___________ Parrt II- irrigator* and Dra nagc System Table 3.3; Crop Coefficient [Kc] Values of different crops
Kc Value as per the crop G rowth Stages 
Croo Type
Initial
Developmental
0.53
Mid
Late
Crop
Period
days
Teff
Maize
0.30
a 30                       0 57
Rice                                             0 30
0.55
1.04 0.64 120
0.94 0.73 140
1 09 0.77 138
N:ger seed(Rainy)
o as
0.61
1 00                0.75                 150
Niger seedlDry}                           0 35
0.71
117                 0.76                 150
1
Sesarne(Ra^ny)                          0 35
D61                               1 08
0.76
ISO
Sesame(Cry)                               0 35                       071
Hancat bean(Rainy.)
0 40                       0.64                               1 09
I Harcot bean'Dry)
0 40                       0.80                               1 17
1.17 0 76 150
□ ZD                120
0 77                120
• Sweet potato
0 50
0.76
1 10
0 91
( 150
' Ginger
0 90
1.03
1.17
1.04
. 791
Black cumin
C 90
T.D1
1.14
1.04
220
O*i on(Rainy)
0.70
0.81
1,01
0 96
121
Ori'On(Dry)
a 70
0 82
1.06
1 00
121
Gar lc(Ra riy)
1
0 70
0 82
1.01
0 97
136
Ganic(Dry)
0.70
0 84
1.07
1 CD
136
Pepper(Ramy)
I 0.60
o 7a
t 01
091
130
Pepper(Dry)
| 0 60
0 80
1 07
0.98
130
Fruits
: doo
1.01
1 15
1.03
365
i
Forages
0 80
0 83
D.B6
0.83
365
Scu ce Dacjs Irngaltor □cvt?loprneri
r
,  1Project, Irrigation and Drainage System F ngj Detail Design Rnport (ZD1S)
3 6. Cropping Pattern
The cropping pattern proposed for the computation of the crop water requirement is presented m Table 3 5. The compositions arc from, cereal, pulses o’l vegetables, spices, fruit and forage crops conside^ng the market a^d local farming practices, for detail refer the
•rrigalon agronomy study report of the project.
The cropping intensity of an irrigation scheme, according to FAO (1997). can Pc defined as 
the summation of a eas covered by crops divided by the total
r
irrigable area; mathematically 
r epresentea by the equation below
Equation 3.3 Where: S is the area cultivated w«1h the crop i in ha and S is Ictal area of the scheme in ha
Wale W- / < s flesigr arc 
r
7
r
C.mo 'l f 1                      »rt4*
Ainl 70*6Ministry of Water. Imgiitor a rtf Elect* city 
□a ous frrgatinn Slutfy ans Ltes-g^ Project
Va’ume- VII Finn’ Operation Maintenance and Safely Manual
_______ Par- II- Irrigation and Drainage System
With the proposed cropping pattern arrangement (Table 3.5) the cropping intensity  of the project is fixed to 180% The perennial crops are assumed to be included in both wet and dry season cropping patterns
Table 3.4. Crapping pattern of the project area
Crop Name
Planting Date
Harvesting Date
Area (%)
Rainy season crops
Teff
01/07
28/10
ID
Maize
30/05
16/10
8
Rice
05/06
20/10
a
Niger seecf/Noug
10/06
06/11
06/04
5
Sesame                                     10/06
06/11
5
Haricot-bean
25/06
22/10                                   4
Sweet-Potato                             15/06
11/11
10
20/06
4
Slack Cumin
20/06
25/01
4
Onion
25/05
22/09
4
Garlic
25/05
09/10
4
Ginger
Dry season crops
Pepper
25/05
01/10
4
Niger seed/Nouq
01/01
30/05
10
Sesame
01/01
30/05
10
Haricot-bean
15/01
14/05
10
onion
25/01
25/05
10
Garlic
05/01
22/05
10
Pepper
05/01
14/05
10
Rainy and Dry Seaso
n Perennial Crops
Fruit
20/06
19/06
15
Forage
20/06
19/06
15
Percent of Total CCA
-
-
160
Source Dabus Irrigation Devefcpme?! Project irrigation and Drainage System Final Dete l Design Report {2016)
3.7. Estimation of Crop water and irrigation water requirement
For estimation of crop water requirement the weighted the crop coefficient, Kz values  and reference evapotranspiration (ETn) has  been taken lhe empirical equation used to determine Crop water requirement (Etc) is
i:r - E7\ * a
34 Where,
■   ....Equation
z ETo - Reference evapotranspiration z Kc = Crop coefficient
J FTc = Crop water requirement
Water Warns  Design a”0
C i i ifl HFi.li *• *>»* « rt fWiarST ipQi
6
Acr 2CT.6Ministry  of  Water  frg.n«an  nnd  Electricity Dabus -rr^a^ic^ Study and Design Project
Volume' VII -F nal Opernlion, Ma iterance and Safety Manua Parrl II- Irrigator? and Drainage System
The crop coefficient. Kfil have taken from the CROPWAT database. As the database does not include Teff and Noug (Niger seed) the coefficients  for these two crops  have been derived from similar crops in the database with minor adjustment of Kc values based on the procedure outlined by FAO (FAO 1994)
The maximum irrigation requirement of Dabus large scale irrigation project is 153.05 mm in the month of February Assuming overall irrigation efficiency of 50% ard 10% flexibility 
factor; the gross irrigation duty resulted to 1.40 l/s/ha is required at the headwork for 24 hour irrigation period at peak season, Which is equivalent to 2 BO l/s/ha for 12 hr irrigation period Application efficiency of 65% has been adapted for estimating the GIWR and field supply 
The monthly gross irrigation requirement is 337mm for the month of Feb.
The calculated net irrigation requirements (NIR) and duty of each month are shown an the following table 3 6 The peak NIR (4,9 mm/day) and duly (0 GU/s/ha) value occurs in the month of March
Table 3.5: Not Irrigation Req uirements (NIR) of Dabus Irrigation project
NIR
Duty
mm/day
mm/montn
l/s/toa
January
3 90
120 3
0 S3
February
4.40
124.50
061
March
34
105 20
0.49
April
24
7060
0,47
May
13
39,10
0.18
June
-
0.01
Jury
*
-
-
August
-
September
0.1
1 60
0.01
October
1.40
4220
0.20
November
2.10
62.30
075
December
2.70
34.50
0.45
Maximum/! otal
4 40
124 50
0.61
Wate- Works Onsigr. ana
■■
AdV 7mr,Ministry   o*   Water   Irrigation   ano   ElneVicily 
Dabus Irriga' cr Study and Desigr Project
Fable 3 6: Dabus Irrigation Project Command Irrigation Scheme supply
Volume-VII -Final Operation, Maintenance and Safely Manual Parr? SI- Irngafior ana Drainage System
ETo Station:* Asosa
Ram station:- Asosa
Jan 1 CB | War
Vontes
' No.          I
cJ
- Cpi
Rainy season
1                Torf
2                Mjl/C Ji no Sore hum
3                           Eood/^DDj, Scsamn and G round-nu!
4             I Itar toj Pean and Soybean
5                Smmcd! potato
5             I Glngcr
7                DIICX cumn a."a yijyc pepper
H               Oman and Garlic 9                Pepper iind Potato ID           | Okra
1-
-
-
-
-
-
1772               •za s
-
-
*
Apr r? 4
-
-
-
50 6
-
May             Jun          July          Aug   I Sco    i Oct      Nev               2cz
-
40
-
5.3
44.6
i-
- 13
-
-
-
■
-
-
-
-
-
J 4
21
53
554
79 3
12.9
31 5
1.
■
■-
-■                     91
• 2 6 ai.B
i
-
-
69 9 oe
35.9           -
5.0             -
137 o            ‘65.fi
-         37
14.7           76 7
1’
|-
-
I-
’-
--
-
-
0.1
a .3         I ■ 1
i-
Subtotal                                  177 2              12B 9                                           73 0
164 9          19
-
17.2
Hairy ana Dry Season
11 Mango and Pjpaya
Ifil 90            157 10               157.30              127.00
70 40
74.4C
-
-
14,4              —
331.B         2sa i            165 4 51 70         121.30         151.10
12              Hanana and Citrus                           149 10            144 43               14520
13             Gt secs. Legumns and Fodder trees
Subtotal
131,50
442 50
127 DC *27 00
421.50 430 SC
125.60
106 50 362 £H3
0 4C
59.DO
203 BQ
-
040
-
-
-
l>> fCMQHI
14 MbIfd and Sorghum 195 20 162-90 1 72 7Q
55 6C              1D6 2C          1 1B3 6O                  T€3 4Q
‘
45 70         103 9C 43 20         95 60 150 60      321 5C
I -                 33,30
ts              Niger HCBd/Woup
Sc**mo and Grou-”x5iul
-
IB
17
+a
19
l*a'<»1 bean arid Soytt’ari Swce! potato
Dn on and Garlic Puppui ana Poiiio
187.10            175 90               4B.S0
1 B2 DO            I Bl 93               167 20
i®3 ao            165 70               162 60
54 40
-
-
-
*
-
*
-
•-
-
*
-
-
27 GO
136 1C 12! 40 400.60
114.30
-
1! El 20
-
-
-
-
45.10 104.10
34.00 111.1C
2D              Okra
Sublnlaf
Grand latai
\te! scriamo irrigation rcquimmcnl 0 n mm/day
0 n rnnVmonlh C in /sTn
160 30
*06 10 T.GSA50
1(15. ID             69 IQ 177.20               1B6 1 134,90            die do
-
1 10 40 41 3Q 60040
1,676 2ij          1 712,30            1 316 50
-
za ao 2fl io
-
117.20
337.90
772 90
54.40
423 10
2 3C |       •
-1
1  17.20
*                03.60
»-
" J              20360
4B2 40 | 713.20
1,174 ae
3.90                4 40 120.30            124-50
3.40                   2.4D
■ 1.30           -
0.10           1.40
Irrigated
irriga bon
Ema (% □! icia! a tea]
0.45 B4
0.51 B4
105,20 6.30 ao
•eau te.Tient fc r ibe az*.ua'              C 53
0.61                   C.4 0
7C.6Q 0.27 74
0.47
39/0           D.30 ; = >5          '
1 82               31 G IB
-
-
-
-
-
-
-
-
1.60 0.01 45 0.01
42.20 0 16 79
2.10             2.7Q 52 30                50 024              0 32 96                70
D 20          0 25            0 <5
i forai
71 7
13 5
117.-?
13.4
737.0
296 2
35 9
13 3
’ 14 5
[ 1,311 B
I  1  00640 1 925 K
514 20
' 2.7*6 40
59B 4Q 563 20
£5160
7C4 70 &65 70
574 50
630 60
4 255 70
B 362 90
t.fil
5* 72 C.21 61 11 6/
a tea [1/sJh)
MR (in mm) for lOOha CCA = 6506C0mm ^herelore, the ictal NIR (in mm) for 9 100ha wi I be 650/00™ Tata' MR (in 0C0 DOOm } fcr 9.l00ha CCA = {(650.600mm x Im^DOOrnm x (10.0a0m )j = 592C46a0m  = 59 22 Vrr
I
3
7
3
1
Waler Works Design and Sufte'visioji Enterprise
1D
April, 20163.8 Irrigation Efficiencies. Duty and Operation Hour
Conveyance Efficiency; Conveyance efficiency  measures  the losses  in lhe conveyance system which comprises seepage losses, operational losses (for example due to rotation of supplies to tertiary urits) and evaporation losses Of these the most important arc seepage losses
Application Efficiency: Application efficiency is concerned with water losses starling from water delivered to the field and available to the crop and includes percolation, evaporation, off targets usage runoff and so on For this project a furrow tyoe surface application method is selected and 0 65% application efficiency is adopted.
Overall Efficiency. Overall efficiency for canals are given by the product of conveyance and application efficiencies, taking into account lhe conveyance and application method (s) and farm management For this study an Overall efficiency of 50% ?s taken for unlmed channel and Furrows type application method
The project efficiencies. Duty and Operation hour of each canal category are presented on the followirg lable 37 below
Table 3.7: Intended Irrigation Efficiency, Duty and Operation Hour
Category
—
MC
SC
TC
QC
Total
Conveyance
0.92
097
0.98
0.9 H
f
a.86
Operational
0 95
0.97
0 97
0.89
Field Apoiication
0,65
Overall Efficiency                0 92
0.92                 C 95                0.95                    OSO
Duty(Vs/ha)
14
233
2 15
204
Ope ran or Hr
24
12
1?
12
3.9, Peak Duty of Canal System
Based on the calculated irrigation waler requirement and the efficiencies  of various components as discussed in the above sections the peak duly in l/s/ha for 12 hour irrigation f or each canal category has been calculated and given n Table 3 9:
Table 3 B Peak Design Duty of Canals
Carafe
Quaternary Canals Tertiary Canals Secondary Cabals 
Peak dutyjri Us/ha 12hr operation 24hr operation
2.04
2,15
2 33
Main Canal                                                         2 80
1.02
1 075
J IL
1 40
Waterworks  'Jcs  gn  and Suocrvisior I '‘'Cra'iSQ
Aoril, 2D1hMinistry at Water, frr.gatior aM EFocIrlcily 
□atnjs Inigalw Study and Design Project
310. Irrigation Interval
Volume- VII -Fmal Operation, Maintenance and 5aicty Manus ____________ parrtll irrigation and □ralngge System
The theoretical maximum irrigation interval is derived on the basis of lhe consumptive use, rooting depth and soil moisture holding capacity  and represents  the period required to deplete the soil moisture reserve The Irrigation Interval is dependent on the growth stages of the crop and soil tyoe. The relationship between lhe crop and the soil is expressed m terms  of soil moisture depletion level Studies  indicated that during vegetative and yield formation periods, lhe depletion level is about 0.65.The empirical equation i_sed to determine the irrigation interval is
a
..................................... ...Equation 3.5
Where,
•    I Irrigation interval in days.
•    AWC - Tolal available soil moisture (FC - PMP) mm/m
■   D - Depth of crop root zone in m. P = management Allowable Depletion in % and
(
■   ETc:- Crop cvapo'rar^piration or crop water requirement (CWR) m mm/days.
For Dabus large scale irrigation project the maximum irrigation interval at lhe time of peak demand is 14 days.
Table 3.9: Irrigation Interval
Crop
Peak (Ja-iy FTc
(mm) aaoDted
Depletion factor
y for lhe
Rooting depth
(IT)
Irrigation
Interval
I
Gross Depth
oF Water
prevailing € T
Appliedfmm)
sesame
5.50
0.55                            1                      16                   126
Haricot bean
5 72
0 55
0.6                      9                     74
Sweet potato
2 23
0.65                            1
43                    153
OHiO’l
92
03                            3 3                      3                     21
garlic
5 18
03
0.3
2
15
peppeF
L ---------------
4 96
0.3
0.5
4
28
fruits
5 94
0.5
1
13
110
Forage
4 42
0 55
1
20
126
Adopted
4.86
0 46
0.71
14
82
3 11. Sizing of Irrigation Unit
The smallest irrigation unit size is tne area irngated at a time by a Flcxl flume during an irrigation turn. The flexi flume must be sized to meet Lhe peak requirement of the crap for highest demand period "he irrigation unit size depends on several factors Most importantly lhe fo'lowing are basic criteria used in Dabus to fix lhe size of the smallest irrigation unit
Water Works Ocs gr- and Suoervis cn E^.e'cr sc
Apr* I 2016MinnVy of Waler Ur gation and Eledr-tiy 
□abts irrigation Si udy and Oesig n Project
•    The flow rate of tile flexi Hume
Volume- VII -F-ral Operjlion MHintenancfl nnd Safely .Manual
_
P aM 11 I rr igati o n and Drain age 5y&:em
•    The rrrgation water application method
•
•
•
The depln of irrigation gift
The irrigation interval
The rumber
of farmers within a single   field ditch
Furrow
stream  size:-
-  is  the  size  of  !he  discharge  delivered  to  each  furrows,  which
equivalent to 51/s m this project.
Irrigation stream size: - is the size of the discharge delivered by flexi fiume and it is 80 l/s in the case of Dabus irrigation project, which serves a group of furrows at a time.
Irrigation Unit: - is an area under each quaternary or flex flume It ranges from 1 to 34 ha
Tertiary Units: - are groups of Irrigation units, with an area of between 2.0 - 335 ha {NIAJ. All fiplds within a unit will be irrigated during one rotation cycle.
It can be derived from the above scheduling that if a Tertiary unit has 2.0 335ha (N!A) it will be irrigated within '4 days interval by stream size of 80 - 6401/s.
F
Wa:e  Works Design and Su-Ce^'Sian I n’crariSM
An-i ??.|£Winislry ol Water. Irrigation and Electrialy 
Volume- VII -F ra1 Oprratipn, Ma ricnance ard Safety Manual
pa bus Irrigator Stjfly a-id Design Proved Pant II Irrigation and Cranage System
4 DESCRIPTION OF IRRIGATION AND DRAINAGE SYSTEMS
4 L General
Tile net irrigation area of the project is about 9100 ha The source of water that can be used for the irrigation development is  Dabus  River The water is  supplied through a system of Main Canal. Night Storage Reservoir, Secondary Canais and To dr ary Canals sriong with the flexi flumes
A surface drainage system is comprises a network of drainage canals (Natural, Interceptor. Main, Secondary and Tertiary drams) of different sizes and capacities to collect and remove excess Irrigation water and surface runoff.
rhe detail list of all canals, drains  and their structures, showing designation, length, bed width, side stopes, full supply dcplh. free board, bank width, bed slope, discharge etc. are given in a separately compiled appendices document, which submitted to the client with the irrigation and Drainage design document.
The detail list showing net command area on both LBMC and RBMC are given on arnex 1 and the layout of irrigator* and drainage system is provided on figure 4.1 below
Water Warks Lfefiiqr arc Sjae-’V stir F. nlurpr se
AcrJ 2016Ministry af Waier, irrgatipr and F ectrl&ty Danns I?rgai.-h Study .me? nrsiqr Pnapc:
Volume V 1 inai Operation Maintenance and Safety Manual ___ __________  p3. n ll- frrigation and Drainage System
r
Figure 4.1: Layout of Irrigation and Drainage system of Dabus farm Irrigation Project.
1
Wale  Wo/ks Desig r .ire Super v sitr Enterprise
'5Min stry cf Waler, trngal on anti Electneuy 
□ahus gallon Study ar-q Design Project
4 2 Canals networks
Volume-VII -Final Operation Maintenance and Safely Manja: Pam II- legation ano D'ainacre System
f
T he following are features of canal networks of Dabus irigafion project -
•    In this project there are two reaches of main canals i.e. LBMC and RBMC.
•    Both left and right main canals are aligned as a contour canal with gentle slope of
1:2900 to 1:5000(m/m) and a total length of 72 35km
•     Main  canals  are  partially  lined  with  geo-membrane  and  partially  unlined  (earthen canal)  with  manning  s  coefficient  "nH=0.03  and  side  slope  of  1:1,5  Reaches  and roughness coefficient n for geo-membrane lining of LBMC and RBMC of the project described under Table 4 1
•     Each command area m surface system is irrigated by a network of secondary, tertiary canals and flexi flumes
•     Secondary canals off-take from main canal, primary canal and partly  rom the ponds (night storage) dunng day time and deliver water to the tertiary blocks
■    Secondary canals aligned before NSPs deliver waler to Night Storage Ponds during the night and to the tertiary canals (TC) in daytime.
•     There are 25 secondary canals, 16 on LBMC and 9 on RBMC side.
•       All   secondary   canals   run   across   the   contour   with   steen   slope   of   ranging between 1/750 to 1/3000 and a total length of 25.659 km
•     Secondary canals have been designed as a trapezoidal section with side slopes of 1 1 5 and manning's ”n’r = 0.03
•     The command area boundary of the secondary canals is natural drainage found on both sides of them
•     Tertiary canals off-take from main & secondary canals and distributing to off-taking flexi flume in Dropartion to the area irrigated.
•    Tertiary canals are contour canals which supply water to the F lexi flumes
■    There are a total of 124 TC’s l.e 86 on LBMC block and 38 on RBMC brock with a total length of 178 38 km
•     Tertiary canals are unlined canals designed wrih manning's ”n" - 0.030 and side
slope of 1:1t
•    Flexi flumes arc canals off taking from the tertiary canal and serve a field unit area.
•     There ace a total of 926 Flexi flumes l.e. 640 on LBMC block and 286 on RBMC block
•      Flexi  flumes  are  designed  to  corvey  flow  to  irrigation  fields  with  flumes  actual diameter of 280mm and a total length of 497 Km Le. 329 km on LBMC block and 168 km on RBMC block
•     Interceptor drains are provided parallel io both left and right mam canals to intercept storm  flow  and  minor  gully  flow  from  upstream  side  of  the  botn  mam  canals  and convey these hows in to the nearest main canal cross dra nage structures or natural gullies
•     There are 39 ID's aligned adjacent to ma rs canas i e 21 on left bank and 18 nn right bank with a total length of 54 78Km
Wale' Works Des Supervision Enltrrprse
*6
Az- 70-fiVestry  pf  Water,  Irrtgalion  ann  Ef«triOty D>bus Irrigation Study ar a Dc^gr Project
Volume* Vti -Fral Operation, Maintenance and Safety Manual f'.'irrl II- .-riga^on and Drain390 System
Table 4 1: Geo-membrane lining reaches and roughness coefficient or Main canals
LBMC-Lining
R9MC -Lining
Chain age
JFram     To               Distance (m)
Rou
Coer
Chainage
From To Distance fm)
Rou
Coer
650
2200
1550
0.0150
_ 5357
6050
693
1483           1600                   117                 0 0150
00150
75Q0
6000
500
00150
.
1044J *2200 1757 0 0150
11672
12750
23017         24660                 1633
1128
0 0150
,
0 0150
20013
22200
2107
0 0150
.
29236 29800 564 0 0150
23BG0
24700
900
0 0150
1
—i--------------- i
J30554
31400
EMS
D.0150
j
— -
_______ Tut Hl
7804
Total
4071
- ----------------.
Table 4 2: Hydraulic Calculations of Main Canals
Ciismaqc          canal
From J I©
Row
Ccwl
Di*
Roq.
7     0.03M         1
FS D
rr»
FR
m
Slope
Hod
width
Sldi
■lopo
rrW*
Flow velocity H/D
m
Sank 
width
m
650 2200 2M2 5357 6050 7500 BO00 8770
SOM 0
2200
7382
LirJng
SCOT
3 217
B 217
0.0150
0 moo
1 70
0.50
SOCO 3
1 70
0.50
5357
SCO?
5CCC 0
7 MS
.
0 0300
1 76
0 50
.
5 50           1.50 .    5 00          0 54          3 25
l/»rhi
5B6B 95      1 400
MGS  35  ‘  1.400
5MR  95  ’  1  400
6050
Lining
*987.0
7 764
0 015Q
1.74
5.66         1 50        5 M           0 54         3 21
.
.
n 50
7500
4927 0
7 764
0.0300
1 74
2.13        1.50        5.00          0 94         1 22
0 50
BODU
Lining
4927.0
7 764
G.O15O
492/  0
B779
SCD3
0.0300
1 74
0 50
11 ODO
4927  0
5670  90  |  1  4no 5545.40  :  1  4Q0 554*1 4.1    1 J. fin
1 SO 5 00 0.84 1 22 ’ 5545,49 1 400
.
1 74
5 66        1.50        SOO          0 54          3 25
0 50
7 764
7 tG9
0 03C0
1 70
__0__5_.1___
5.00
4876  0
54           3 25      5545 49      1 4M ’
I H POP 1 1622 SCD4
0 53          3.15      5120 96      1 4C<1
1’622 12750
14330
1 zoao
____________. _____ _ _______ TO 0.50 . 4876 0
’J75C         Ljn-ng
7.16§ " g Q15Q
77.1,12233 0 0150 ’ 70 D 50 4B7J a
'4330           SC05        7 123  '  0  0300 _    t  70 1     0 Sa  <g73~0
1 50
1 50
1 50
1 50
5.00
5 00
5M
0.92         1.17      512C 96      1.4CO
3 92         1 16      5087.51      1 400
17000
JL643    ' □  0300      s  70      g Sa  4iB23 0
17105     17571
A?L®L_. PQM 6 643 CLOtSO
17571 __SSCCO08B 4 4 6M63] 0 0150
1 20013 SrCoa 4 567 aoTso
70013
. 22200 Lining 4,473 | 0 015Q
222DC    22650 5C1Q 4.473 | 0.0300
22650      23000
J 889 I o.oioo 1 an
23600      24700       L -Ring      3 889      0 01 5G       i 36     , 0 50 *    4360 0
_
4873  5 4523 0 4510 0 *439 D 4*99 0 43BD 0
24 700     27100
27100 27250 sen
1MB    ’ 3 MB
0 0300
00^55
1 36
50
2/266      29019        SC12        2.517      D 0150       1 10       0.50
1 36       2 50
43MQ
43800
4034 0
1 so        5 00          0 S3         3 13      5087.51      1.400
1 so        5 □□          0 S3         2 BS       4/44.75      1 400
I 50        5.00          0 01         1 01       4744.76     1 400
1.50        5.00           0 M          ■ a?      3345 2Q     1.400
1 50        5.00           c as         1 02      3262 04      1.400
i 1.50          5 00          0.95        •J 97      3195 27      1.400
1 1 50         5 DO          0.49          2 7fl      3195.27      1 400
1 50        5 CO         0.46         2 91        2777.44 ’   1 400
’ 50         5 M           a Hj         1 04   I 2777.4*"  1 400
1 50        5.00         c *<?        2.91      277 7 44      1,4 CD ‘ 1.5D        5 00          0 83         1 04       2777 44“     I.4QC ’
25019 305M SC13 1.727 i 0 0150 1 05 0.5O 3835 fl
30554 31400 I irung *. 571 0.0150 1.00 a, 50 361 7 0
31400 351B4 SC’4 1 571 1 O.O300 1.00 0 50 3617.0
1.50       5 CO
0 76
3818*
Sion
37073 seis ’ 5*7 a G30C 1 DO 0 50 3617 0
19984 SC15 ’ SD2 G 0300 * 00 0 5O 3577 0
150           5 00 t 50        5 DO
1 50        5.00
0 71
0 71
Q4|
1 50 5.00 041
l fiQ 5 00 0 41
1.22         irae'si ~   1 *oa“ C.7O       *233 23      1 400 "
0 71        112240      1 400
7 3a       112? 49~   i 4nn
2 26       lies C?8      1 4D0
2.Hi       1072 97      I -li?:
Warks Lhisign Supc'v 5 cr Enterprise
Aoni 22JIEV
Hi
fl
H
M ri*1ry of Wale' mgaJian and Lle-cjricjty Dabus Irrigation Study and Des gr. PfO|£^
Vo ume- Vil -Hna[ Operation, Maintenance and Safety Van^a
p arrt II - .-rogation and Drainage System
Cfi-ainage           CANAL From
1-
Div. !
|
ftou.
Coc(
HYDRA
F'.S.P
ULIC CA
F.B
m
LCULATIO
Slop*
Bert
N OF 40K
Wltflll
C
S«3e
nope
Bank
wicth
Rew
velocity
a/o
irrl.
Duly
m
m
m             m/»
ha
I/S71U
0
50
4.536      o moo       1 51       0 50      4515.0       3 83       1 SO        500           fl 49         2 53
3239 87       t 400
w
1483
SCCi
4 536
0 015-Ci
151
D.SO
4515 0
1 27
1 50
5K
0 as
0.84
3239 87
I 4DC
C
fl
1483
1600
I *>"9
4 152
D.0-5C
1 51
OSO
4477 0
1 03
1 50
5 00
D 64
0.6B
797? 8’
1 400
1GU
3200
4.tG2
0.030Q
t 51
so
4477.0
3 40
1.50
500
0.40
2.25
2972 81
1 400
3ZX2
3844
TCOT
4 182
0 0’50
1 51
0.50
4477.0
1 03
1.50
5.00
□,n4
0 e«
2972 81
1.400
3844
5650
j 4 136
D.D3O0
151
0.50
4433.0
3 33
1»
5 00
221
7947 27
1.400
5S5Q
7027
SC02
4.128
0.0150
1 51
0 50
4433 0
l no
1.50
5 00
OM
0.66
2947.27
1.400
;a?7
i 915C
3 GV
0 0300
1 43
0.50
4358.0
3 20
1.50
5.0Q
048
2 2*
2583 34
1 40C
I
■
QI 5Q
r044i
SC03
3 017
0 0)50
143
0.50
4358.0
0.97
1 so
5.00
0 82
066
2563.34
1.400
11K43
I 2200
Luing
3.027
0.0150
1 36
0 50
4218 0
0?8
1 50
500
0 79
55
7162.01
t 400
12200
16450
3.027
0 0300
1 36
0 50
42180
2 79
1 5a
5 no
46
2 US
7182 01
I 4 00
154 50
10490
SCO*
3.027
0.0150
1 36
a 50
4216 0
0 78
1 50
5 00
0 79
0 68
21G2.01
1 400
1&49A
17429
PCfll
2 164
0.0150
1 25
fl so
4032 0
0 /a
1 50
5 00
0 76
0.56
1545.46
1 400
’7429
23017
SC07
1 625
a ciso
1 09
0.50
3735 0
fl ?Q
1 so
5 00
0.73
0.6.
1160.37
1 *00
23017
24650
L tnirij
1 382
a 0150
1 Q«
0.5O
3650 a
fl 70
VW
5 DO
Q 72
0.67
986.91
1400
fl
246 SO
28A5C
1 367
0 0300
104
0M
3650 0
’ 74
1.50
5 0Q
0.40
1 67
98691
1 4G0
2AC5O
20236
SCu8
1 182
0150
1 04
CW
3650 0
0 70
tM
5 00
0.72
067
986 91
1.400
29236
29800
Lwg
C 274
■3.0150
068
0 50
12CC 3
0 50
1 50
5 DO
0,58
0 74
267 71
1 400
fl
29600
31850
0 374
0.030(1
0.68
0 50
32DC
0 78
1 50
5 no
n 31
t is
267 21
1.400
31850
37348
SCOT
0 374
0.0 ISO
0 58
0 50
32DC O
0 50
1 50
SOO
0 Sfl
0 74
267.21
1 4DU
fl
fl
II
fl
fl
fl
fl
fl
fl
4.3. Canals and drainage structures
a) Canal structures.
<* Cross and Head Rcgulators;-
•    Cross and Head regulators have been provided in the Main Canals (RBMC ft I BMC), at the off take of secondary & tertiary canals, respectively.
•     I he regulators have been designed for submerged flow condition with a max;mm driving head of 0.2 m
❖ Cross Drainage Structures:-
• The cross-drainage structures are of two basic types, Culverts ano Siphons. *> Drop Structures: -
A vert cal drop structure has been selected for this project
'he im and 1 5m crop heights for SC’s and 0.5m. ft Im drop heights for TC’s have Peen used for the project
"he'e are cc drop structures on the main canals,
Water  Works  Desgr  ana Supervision Emsronap
*0
Acr'.i, 701 r.Ministry of Water, lr :ga! an and Lledricity 
r
Volume- VII -Final OperaVon. Maintenance ar*d Safety Manual
Dabus I rrgation SI l rfyjira Des>g n projed _________________ Pari ]J- trrrga hon and Drainage Sys I e-hi
*!■ Road crossing culvert;-
■ Road crossing culverts will be provided where access routes are cut Dy 
carals or drains
•    Pipe culverts are designed oased on the 1 in 5 year rainfall event
b) Drainage structures
•> Drain Drops; -
•   Low masonry drops will be provided along the tertiary
•   Pitching will be provided upstream and downstream of the masonry structures
•    The drop heights of all drains are limited to a range of 0.5 and 1.5 m.
❖ Drain Outfall:-
•   dram outfall are provided at the outlet of all drainage canals.
•   A minimum outfall1 (level difference) of 10 cm to 20 cm is prov’ded
Detail of the overall canal structures wrthin lhe irrigation system in this project summarized in lahle 4 3 below
Table 4. 3: Canal structures detail of the project
S/N Description
____________ Unit LBMC R0MC TOTAL
1   , Main canals and Associated Works
Head regulators
Nr
15
10
25
Cross Regulators
Nr
13
10
23
Escapes
Nr
5
7
12
Cross Drainage Culverts
Nr
0
7 1     15
Night Storages
Nr
11
8
19
syphon
Nr
1
2
3
2       Secondary canals and Associated Works
Secondary Canal Cross Regulator Tertiary Canal Head ReguiaLur                Nr        63          9          72
Secordary Canal Drops
Secondary Canal Culvert
3     Tertiary Canals and Associated Works
Tertiary Canal Drops
Tertiary Canal Culvert
4      Flexi flume
Chamber
5 Drains structures and Associated Works
Outfall
Drop Structures
Nr 143 63 206
Nr                      2            2
Nr      268        64         332 Nr                      3            3
Nr 1244 912 2156
Nr was 390 1468
Nr 2352 143? 3784
Warks Des gr arc SuDCV'S o  Fnterpr-se
*9
April, 20*6
nMinistry  atWa*c'  iTgation  and  Electric  ty DatLE Irrigation Study and Design d-ojec*.
Volume- VII -R-naF Operation Ma nlenancc and Safety Manual Parri II irrigation and Drainage System
I able 4. 4; Canal structures detail of the project
Summary of Structures on LHMC
Structure
Canal
MC SC I TC QC
Drain Canal
3D I TD QD
Subtotal
CR Structure                      13                                                                                                                      13
’ |R Structure 15
Syphon Structure                1
I
I
15
1
CD Structures 9 9 J
Escape Structure                5                                                                                                                        5
Nigh! Slnraae                                   11                                                                                                        11
SC-CR&TC-HR                                63          68                                                                                        136
TC-CR&QC HR Chamber
Drop Structures
0.5m
624           624
1334
144        270
13         180
1248 1334
11 255 4743 5423
172           3534                  3699
1 Om
51
78
11
54
1203
1403
1 5m
80
12
29
0
121
Outfall                                                                                                             700            413
1 * S3          I
Total                     28         238        962         1958
11          1035          5155                  9388
Canal
Summary of Structures on RBMC_
Drain Canal
Structure
MC        SC      j TC             QC      | SD            TD |           QD
Subtotal
CR Structure                      10                                                                                                                      10
HR Structure                                    10                                                                                                        10
Syphon Structure 2 2 1
CD Structures
7
I
7
Escape Structure
7
I
7
Night Storage
8
8
SC-CR4TC-HR
21
21
42
TC-CR&QC-HR
i
288
288
576
Chamber
912
I
912
Drop Structures
1
W7
36
4
75
2261
2484
0 5m
26
6
0
43
1812
1087
1.0m
1
48
12
2
29
449
541
1,5m
33
18
2
3
0
55
Ouira 1
367
172
539
Total
35
13B
34S
1200
4
442
2433
4597
4.4.     Flexible Gated pipes (Flexi flume)
4.4.1,   General
I lexi flume is made up of strong irlerwoven fibers and flex'ble polyethylene with adjustable outlets. It is used as a substitute of infield earthen canal for the distribution of water within the irrigation system This type of water conveyance system is preferred to any other earthen open canal due to ;(s following advantages:-
•    Il has the capacity to handle large volumes of waler over a variety of terra ns
•    Very high water conveyance efficiency                     as compared to the open earthen canal efficiency (70%):- the system helps lo deliver the water from the supply canal
Wale'  Works  Design  ano Sunctv sc*: -irerzrise
20
AO'.. ?01fiMmixlry nf Wa'e' Irngaton and Electricity 
Dabus Irrigation Study am Os.gn Project
Volume- VII -Final Ope<ai on. Maintenance a“d Safety Manua
_ ________ Parrt >- Irrigation ano D^amage System
to lhe field with no water loss due to seepage evaporation, leakage, overflow, etc Therefore, up to 30% waler saving s expected
•     Better water distribution efficiency in lhe Furrows lhe uniformity for surface irrigation system is more commonly characterized by its distributor efficiency and it is a mam parameter  to  evaluate  a  system  Flexi  flume  irrigation  has  got  02.4%  distribution efficiency as compared to 64 3% distribution efficiency or open eaithon canal due to the  controlleo  wate-  flow  through  the  openings,  hence  10%  increase  in  land productivity is expected due to proper irrigation.
•     l abor  saving about  30-40%  less labor Is required as compared to open earther canal.
•    Almost no or very minimal annual maintenance cost as compared to lhe other one
•     Increase machinery efficiency - no hindrance in lhe middle of the field and hence lhe machine can work end to end in the field for inspection and other related works
•     Additional revenue from land saving1  srnce it requires a very smalt land ’,o lay Flexi flume, the land can be utilized efficiently far croo oroduction.
4.4.2.   Use of Flexible Gated pipes (Flexi flume)
Flexible Gated Pipe (FGP) ts an improvement on furrow irrigation, in which the conventional feeder ditches and siphons are replaced oy an aboveground "lay-flat" plastic pipe Based on Operat?on and Maintenance (0 & M) Manual for Surface irrigation of Welen chili (Additional) Sugarcane irrigation Project report, Feb 2015, Furrow irrigation system using flexible gated pipe has attained an application efficiency of 90% for a recycling system and also 35 to 60 percent reduction in water and labor costs  can be attained. Adjustable gated outlets minimize lhe effect of pressure head differences  on discharge rate. Irrigation waler flows from pipe outlets, which are regularly spaced along the pipeline with an interval equal to furrow spacing
For a given pipe size, the greater the flow, the greater the velocity will be so that the greater the erergy loss by friction. Friction losses are not linear - doubling the flow may increase the friction loss by up to four times. This energy loss cannot be recovered As energy m a gravity system s fixed oy the elevation difference present !ost energy due to friction :s usually an important design factor Pipe size is selected to 'match* pipe friction loss to the available head to achieve the desired waler flow rate
4.4.3.  The Role of Flexi flume in Improving Productivity
Land Saving: Based on lhe information of Civil Eng'neering on fields a ready engaged with Flexi flume, the land saving supposed to be nearly 1% when lhe area occupied by Feeder di*,ch and Flexi flume is compared.
Labor Productivity: I abor productivity especially of irrigation is improved for there arc no irrigation materials to transport simply irrigating means opening & clos-ng of valves in Flexi llume system Hence a lot of jobs are executed without fatigue. Operators and drivers are
Wair Works Des gr and
S-perv'siQn &r.te or sc
r
:
Anni, 20’6Mi^slry of Water Inrigaton and Electricity Daous .viga-igr_Srudv and Rcsigr Project
Volume- VII -Final Operation, Ma nle nance ano Safely Man hr I
Pam II- Irrigation and Drainage System
working without stress for there are no obstacles in the fields every activity were executed at one go straight A forward without using reverse gear
Land Productivity: Due to application of Ffexi flume it is already nDserved that proper irrigation can be applied, as a result, uniform growth of crops shown in most of Flexi flume fields Even Ihough it is difficult to estimate land productivity cased on the improvement attained so far, it car be assume that not less than 5% increment in land productivity
4 4.4 Design parameters of FGP
The following design parameters are considered n the design of FGP
• Discharge of water into the pioe from irrigation canal has the following form
Qp - Cd-flgh
................................. Equation 4"
Where,
h - pressure head above the pipe at the inlet box (cm), and C discharge coefficient (0.6);
2
g gravitatiuna. acceleration 961 om/sec ;
A cross seel ion al area of the pipe (cm ), Qp - water flow through the pipe at full (lil/scc).
2
• For pipe diameter of 42.5cm, g = 98'cm/sec2 and C = 0.6, the relationship between pipe discharge (lit/sec) and h (cm) will have the form
=37.657* 
Equation 4 2
•    From the above equation, discharge through gated p oe is mainly dependent on the available head The discharge-head relation of ftexi flume pipe of this project is described under Table 4 3
•    On the utner hand, discharge of pipe out let depends on the pressure inside the gate The pressure depends on the slope along gated pipe (bed slope) ano area of out let opening This suggests relation of the power s represented in the following form
q - ch'
....................... ........................ ........... ....................... Equation 4 3
Where,
q - in l/s.
n the operating oressure iri cm,
c.- the coefficient dependent on gate opening area and took different values for different gate openings,
Wa:e’   Wtrks   IJnsiyi   ana Sjperv sr©fi Erinrr.’isp
Apr I 2C1Sli
u
« I
I
I
I
I
« I
i
■ di d d d d dl d d
f hl 7m r* 4 'Ji-          m *■»'- r
/>Z«*          ?
I IdJr'J., I^.ijrtt
**-*■■*/ •'■'V»
J               4*>Z      - --------- " >-Z*
**T. *W -
/ fyi?'r7 tj/p<Z4^rf 4*# 7/W/>y <= > $ >Z 1/W !’
4
’6r*
■ I Of 11 ijfhlofm
'/ //4>Z ^'/z^
l*> pr«CC-Z* z<Z#XZ t4H*W
Ilfat     rtfld     ItW     liitt     Ol/tkd     tf/Z/W     ,'A     Z/z^/     rtb/     ?sZ     z».     *^C-r     ’     %>■     /<S*"     <
10% dlV.thlf'Jfi WiZ//. '/
<Z/ZZ-
Pr r y gT.
zr,-
-rjpiflrz -< i
• Friction looses afong r^de dfre p«s 
rrz ce rb#* ^rrriiar 'rz dl uce ^stenais.
Selecting proper ppe ard T.ater;®l will <eczr< zr lirxrafie -Rcwr^i =fitt avarlable bed slopes  /Ava^/*z  gfe ma?/ to discrgry>i terr xuler ami 'er have 5he same value. Simriaify  escr ^re meCiema jril -sue 3^-tssik zz^-L-e-.— value beyond which the pipe ~sy  zzz^i “'^rerxe srer _c  ^rrvxrzrc. tre technology, these parameters shoue be ^andeb Txer.i
Table 4. 5; Relation between flex: flume oitie! =f&c*^r^ O tnr zr-wr^rr rivsr: ’r
Diarneter
m
Wej
S’
cs
-ten* aia^WS 30*
-*IE
m
TF
Tr*c.
XE
0 29
0 062
ba
U^a ■
x-s
f
i-
D ?a
0 062
05
■flZ?
ZTE
115=
s.
□ 2ft
0062
06
0 23
L
r~
IF
0 29
0 362
05
□ 21
r-.i
T 7==
S
0 75
0 3£2
05
335
r m-
—
0 29
0.062
3-5
335
EJ
ira
—
0 79
□ D62
0.5
3U7
I2T
rjns
0 29
0 062
□5
33E
r, r>
tra
—
0 29
0 062
□5
CIS
JE23
LET
75
029
0 062
06
a:
L?*
t BE
E
0 28
0.062
05
•3 * -
T
LX
fF
0 78
0 062
05
17
L LS—
n
0.79
0 062
CL6
Z*4
tm
135
0 28
0 062
OS
a*-t
XT'S
iisr
IF
0 29                   0 062                   as
-■, t c
ir?
J-JStt
0 2B_ 
QJpfij_________ g s_______
. _ S.T5
T.l:
j PSI
-U A ■. • 
XJ
*• 
k — 
JJ
Q 2ft
Q r’^r-i
i’S <
■- «■ B
4.
r-
,fa.
0 29
~ —------
J- -CM
0 062
as
«■
au *
LXE
3
Ft
Q 2ft
0062
ds
e;a
D 2S
r xst
dose
a?
a-F*
r r>
; ?<-’
3T
0 2 ft
0«C
as
■*.
: fat
0 2ft
GOW
ce
4F*
r ■ "'
T .VS
s*
11 2ft
G
c*
e.-
; ftf
r ir
ll 2ft
•vr
o ww
o fot:
06
aa>
0 2ft
? 3?
2 -tlX-
06
-xr
33=
:-
I it?
ll 29
0 062
ix:
OS
S w *■
4■
r *’
‘: tS
Sj
0 29
oao
0 062
as
ow
???
2
.- >
as
«
vJf
2*S
%• N
0 28
0 062
ur
as
03
2«
r iw
'■3F
0 29
0.062
os
49^
E <9-
11 7ft
o u.
0 06?
06
ti.SM
dsii
r.
C - ■ ■"
0 0ft?
Oft
4 S3
r.<
r-
h 1 "ta.
0 2ft
O Oft?
06
0 9«
c <■
<
0 2ft
0 0ft?
0-i
4 St
a
c- •<
■m:
028
0 Oft?
dwi
46
t 3S
•J 2ft
o>
* >L.
V -.
r*
■r
t£
3
r
•3 28
0.C6 2
• • 8
C 3S
ox
? ^F.
-ir
9 28
<!&:
06
0 3*
jV
r
• «>
0 28
fed
t4
0.
r .X
*3”
VViH^‘   VVivNm    l\l^4?   ft   M Si pOA * !'•’ I •"»»• iu-M*Min 51^ al Waler Irrigation and Electricity 
Dabus Irrxjat'On Study and Design Pr^flci
Volume- V I -Fin,i Operation, Maintenance* and Safety Manuo ________  _________ Parti II- Irrigation .incj Dra’^ce SyrZr-n
0 2B~
gas?
3 6       ~~~               o<1 _ ~ a 65
0 1TZ1_2” '
_ C?B _______ J OB J 
4.4.5 Components of FGP
0 6  J_________ □ *2_________ :____ _______ C 56  ________ D 122
122
Commercially  there are different types  of flexible gated Dices  such as  hydroflume, flexi Hume, ezy flume and so on. The proposed type of ^GP for this project is flexi flume The system comprises an inlet box, joiner, clamps, punch, outlet openings with adjustable gates and the pipe itself Pipe types are selected based on internal frictional losses together with their Permissible pressure heads (he following are major components of the system
•     Inlet box: Il is constructed from concrete material across tertiary canals where the pipe  is  installed  To  control  water  distribution  arid  discharge  amourf  two  gale structures will be fitted or the box: the first one is peroencfeular to the tertiary canal while the second one is parallel to the canal at the oipe side bottom side of pipe outlet from the dox should be al the same level of pipe bed
■ Joiner. It is used to join rolls together as well as to join the pipe with inlet box it ts made of hot galvanized iron sheet.
•     Clamps:  Clamp  consists  of  the  be*t.  which  is  made  of  stainless  steel  and  screw mechanism made of anodized iron pieces. It is used to fix flume an joiners
•      End  clamp:  End  clamp  is  made  of  strong  iron  profile  and  galvanized  iron  for corrosion protection it is used to close end of line or to control How of water
•     Outlets: Outlet consists of two parts, the base, which is made of Pexible PVC  and a
4
cap made of Polypropylene It may  be easily  installed in any  point of the path It consists  of valve and an attached waive to control the flow of water. Opening of outlets could be adjusted with the help of sliding or circular gates Outlet diameter of flume at Dabus is 280mm
•     Puncher. Punch consists of base and cap made of F’olypmpylene and cutting head made of stainless steel This tool .s used to make holes an flume to nstall outlets
•     Riser: it is made of metal, bricks or any other materials used to maintain a constant head
4.4.6. Installation procedure of FGP
•    Measure field lengh of run and field slope on which the pipe is to be installed.
•    In order to avoid rolling alter Tilling with water dug the entire length of run (a ditch approximately 10 to 15crn deep) to hold fluming in place The bottoms of the ditch
and the furrow should be al the same level
•     Cuff back 30cm of fluming to form a double thickness over the pipe before securing with a hose clamp. Pipe diameter must be same or smaller than burning
•     If the pipe is not leveled with ground, shovel a mound of drrt to support fluming This wilr ensure even Tow of waler to the furrow. Avoid sudden bends or folds
•     To join an additional length of fluming together insert a 30cm lenglh of rigid p?pc  of the same size, completely into the end of the frst section oF the tubing, then cuff back second tube section to form a double ayer and slide it over the first tube section.
•    When the tube is used for irrigation, the water should be held tn it. so an end damp is used to dose the end of tne line
•Wa!■_! WtrRs rtRsigr anti Enterprise
/Vgrtl 2C "6M*risiry or WateJ’, Frr*g alien and Erectncty 
Vciurne VII -Final Operabnn Mri inter a nee and Safety Man..a
Qabus 'rrigatie^ Sljdy and Design Proiec* ______________________ Parr* ;l- Irrigation and Dranage System
o In case lhe lube is used to transfer water. to prevent deterioration of tubing fror^ loggirg, nsert a rigid sleeve inside the lube end and secure with clamp properly Stake rigid sleeve to ground to prevent movement
•     After securing tube end, if possible, begin with moderate waler flow and gradually norease to full flow
•     Start holo cutting from intake end of the tube The holes must be positioned at the center of the furrow
•    Grasp hole-cutter in palm of your hand and with a firm thrust, pierce fluming tubing just 4 or 5cm above the center of the tube or al a position of 300 from lhe ground. Keep cutler clean and sharp.
•    In order io install the outlet
d First remove rotating valve, Next press retainer ip downward with your thumb, inen exchange nolo to your middle finger and squeeze entire valve seal to narrow lip d'ameter Insert unfolded portion of lhe lip first then insert entire lip mto hole.
c Complete insertion by pushing folded portion of lip against Lhe inner surface to the tube wall
o Install rotating valve and adjust to desired ilow
■ In order to remove, grasp out lei from bollom and pull up and out
Installation of Flexi flume Outlei
Removal of Hex I flume Outlet
Figure 4 1;- Flexi flume Outlet Installation and Removal procedures
Water Wu^s Design and SuDcrvisior r-'p-n’iuu
75
Acfii 20161
Ministry a f Water, Irriga ! and E'ecSi'icily 
Vaiurne- VII -Firal Operation, Maintenance anil Safely Manual
Danus irrRation Study and Desgn Project________________________ Parr*, lbJrngairon and Drainage System
4.5,    Night Storage Reservoir
Night storage ponds are planned to store water *1ow for 12hrs during night, all the canals arid outlets shall remain dosed A minimum of 0 50m freeboard will be provided above the pond maximum full supply  level to accommodate the design wave height. In most cases  the combined requirement for 'reeboard will be less than the requirement to maintain the NSP embankment level at the same height as the adjacent secondary/Mam Canals Substantial seepage fosses  are likely  through the NSRs  and ‘hat consequently  1.2mm thLCk  Geo membrane lining will be provided under each NSR and up the sides. The membrane will be covered with a minimum of 4C0 mm deep soil layer to orotect 4 from physical damage The capacity/sizes of NSRs are varied according to the blocks sizes that are commarded by a secondary canal Making the operation ease by reducing the water travel lime reducing the size of the main canal and the operational loss  in the main canal minimized could be mentioned as benefits from ponds There are different possible options afarrangemenls with regard to lhe connection of NSP with canals. For Dabus  irrigation project, based on the tODographic  nature of the command area, the NSP at the middle of secondary  canal arrangement was  proposed The total number of secondary  canals  in lhe left bank  of lhe command area that are branched from lhe IBMC are 16 For these SCs  11 NSPs  are provided to supply water for the command areas. Similarly in the RBMC there arc about 9 secondary  canals  & 1 tertiary  canal, or which 7 & 1 NSP are provided respectively  The capacities of NSPs in this project are described in Table 4.5 below;
Table 4. 6 Capacity of Night Storage Ponds
Block Name Total Area (ha) Discharges al Head of
Secondary Canal
NSF? Capacities
(m )
1
LBMC
i
|
SCOi
132.05
0 155
7690
SC02
75.41
0 OBB
43 70
SC03
201.67
0 236
11680
SC05
234 37
0 274
13570
SC06
95 99
0 112
5560
SCC7
B44 89
0.989
48900
SC08
33 25
0.097
4820
SC10
269 Bfi
0.339
16783
SC1 1
011.45
0 949
46970
SC 12
432.94
0 506
SC16
25060
B84.19
1.037
R6MC
SC01
51310
66 3
0.101
5000
SCO?
220 6
0.258
12770
SC03
148 38
0 174
8590
SC04
616 55
0 721
sees
35690
298 !2
0 35
SCCB
17290
319 50
0 374
SC09
240.16
18500
0 281
‘•3900
TC01
25,54
0 030
1480
Water Wc ms Design s
rd
26
Supervision
Aor 2016M nistry til Waler irrigation and Eiednedy 
Volume- Vll Final Operation. Miimtenarcc «ind Sa'ety Manual
□□bus In ptiuofi Sludy and Dns.gr Project  _________________________________ Parrl II Irrigation a <i Dramage System
n
4.6.    Hydro-Mechanical Gates
In Dabus arge scale irrigation project gates are provided on mlel & outlet of canals (SC's. TC's. & QC’s). crass and head regulator structures of canals, escape structures and mghl storages. Detail of hydro-mechanical gates within the project is summarized in Table 4 7 below
Table 4 7. Steal Work/ Hydro mechanical Gates within the project
S/N
Description
Unit |    LB.MC |    RRMC       total 1
Xiplil Storages
InkrL Siruc tires
Cross regulator gates rvbdrtg hooting
device
PI
1
Outlet Siruc urcs
Cross regulator gales including twisting
device
Xr
Xr
1 1.00
11.00
s.oo
S.OD
19
Cross Rezutaors
Cross regulator gams hetudre ho sting
device
11. CO
8.00
19
Sernndnn can*b and Associated Works
2
secondary canal cross regulator and tertiary cnnnl head rcgulilor shfifc leaf metal sheet *trti:al mechanically/ linrid operated sliding
gils_
Xr             17U
G
213
Tertiary Cauls and Associated Work*
3
tenuirj canal cross regulator and quaternary canal bead rcsdatar single IcnfiriLial sheet vcriic.il mechanically/ hand operated sliding
cates.
Xr
iW            nt           931
Quaternary Carrals rind Ass Delated Warks
1
tertiary canal cross regulator and quaicmary cared head reguhtor smglc leafmetal sheet virtual mechanicals rand operated \Mr«
$£l1C5.
r—
Xr            2668                             4 02 1
ISM
Ws;e*W3’^ Design and
Supers' s. F-r’lprgnse
Atini. 2016d
Ministry o Water, I <riga" dc arc Electricity 
□abut frriLjniinn Study Oes gc Pre tret
Volume- Vti Tina OnrraliGi Mii<rren«nce and Safety Mijnua ________  Parrl it Irrigation and Drainage System
5.       IRRIGATION SYSTEM OPERATION PLAN
5 1     General
The puroose of Dabus Large Scale Irrigation Project (LS1P) aoeratron plan is mainly to ensure proper management ar irrigation agriculture and equitable water distribution among farmers based or unit area The ooeralror functions of Dabus large scale irrigation project include the following major tasks
Main Dam - mainly concentrates of Operation of Gale o* Outlet
Irrigation System, his part mam deal with the following details -
•    Operation of Gales of Head Regulators of Primary canals.
•    Operation of Head regulator Gates of Secondary Canals;
£
F
•    Operation o  Head Regulators Gates o  Tertiary Canals.
•    Operation of the Escapes and Head Gate
■ Operation of all other gates;
•    Assessment of water requirements,
•    Conveyance and distribution of water
•    Distribution o scarce water during water stress periods; and
r
•    Drainage of excess water from fields and eventual re use or removal.
Tnc irrigation operation plan describes the allocation and distribution gf lhe available water to secondary blocks, tertiary units and flexi flumes It enables farmers to ’ormufate operation schedule, the contact duration in irrigation and to momlo* water loses This abjective is achieved by the following activities:
•    Preparation of an irrigation plan
•    Operation of the water dislrbution according to the irrigation plan
•    Monitoring of the water distributon and
•    Adjustment of the plan, where required
Irrigation plans are prepared we ’ in advance of the irrigation season f he plan will be based on the expected available flow in the rvver and the water required by the farms for the crops proposed to be sown. This will mean carrying out uf lhe 'oil owing activities
•    Estimating tne future suppiy
•    Estimating the water demand of the envisaged nupping pattern
•    Matching supply and demand
•    Taking Restrictive measures to match supply and demand
•    Distribute enough water according to lhe demands of the water users and
•    Fo low up the impending waler shortage o flood to and suggest remedial measures.
r
Water Works Des gn anti Suce'vis.on I rlewse
23
Aon:( 2DiDM r slry □ f Water. Irngahon and Ffectecily Pao„5 lr-gaticn Study and Resign Priced
Volume-VI ' -rmai 0 neral ion. Maintenance and Safely Manual Parri II- irrigation and Drainage System
The expected water demand shall be estimated from the planned cropping pattern, irrigation requirements, irrigation efficiencies  and (he estimated effective rainfall. The information on tne cropping pattern, including dale of sowing and areas sown, has to be collected from field. Climatolog.cal information has  also to be collected, □nee the supply  and demand is estimated, .irrigation dan can be prepared.
5,2 Operational Plan in Main Canal
"he layout of main canal is the most rmportant and vital component of the entire planning work After constructing diversion weir the water w»tt be diverted and conveyed through main canals until distributing to the primary canals (PCs), tertiary canal & all secondary canals. At the diversion off taking point both RBMC and LBMC have FSL value of 1004 5 m. Main canals  in both sides  are designed to convey  1 4 l/s/ha unit discharges  including 10% flex’b lity factor for 24hrs continuous supply when irrigation is required. Along the contour section of the main canal the embankment is designed to serve as inspection road so {hat provided with 5 m width An interceptor drain will be provided parallel Io each main canal, approximately  25 m from lhe canals  center line, to intercept the runoff from the uplands. Dra n canals m Dabus irrigation project designed to convoy 2 969 l/s/ha flow and dispose to natural gullies or the cross drainage structures
In the design of the left bank mam canal design gradient varies from C 02% to 0.03% , design discharge varies from 1 5D2 m /s to 8 217 m’/s, free board is 0.7m, velocity varies 
3
from 0.41 m/s to D.54 m/s. flow depth varies from 1m to 1 7Sm Smiterly lhe right bank ma n
canal design gradient varies from D.02% to D.03% design discharge varies from 0.374 to
4 536 m*/s. free board varies from 0.5 to 0.7m. velocity varies from 0 3 m/s Io 0 49m/s, How
1
depth varies from 0.68m to 1 51 m
5.3 Operational Plan in Secondary Canal
All Secondary  canals  run across  lhe contour They  run down the prevailing slope with frequent drop structures  Based on the design criteria lhe proposed drop height tor secondary  canals  is  tm &1 5m Secondary  canals  designed to convey  2.331/sfha flow including 1D% flexibility factor for 12 hrs /day dunng day time for secondary canals aligned after night storage pond ard 24 hrs /day for SC s aligned before NSPs and distributed oown each off-taking tertiary canal in proportion lo the irrigated area. Night storages are provided at the middle of SC's to store the 12hr irrigation water during at night time. Dunng day time the SCs will receive water from both the mam canals and night storages at same time. The FSL is typically around ground level or just below as a consequence of balancing cut and fill. In addition, lhe water level has  been set to at least 0 30 - 0.40 m above ground level uostream of cross  regulators, so that off-taking tertiary  canals  can command their head 'eaches Secondary Drains are designed with 2.969 l/s/ha dram duty, to colled excess flow from secondary canals and tertiary drams and discharge to natural gullies.
5 4. Operational Plan in Tertiary Canal
The tertiary canals are designed to convey 2 15 l/s/ba flow for I2hi7 day, Tertiary canals supply irrigation water to tertiary units All fields within a tertiary unit will be irrigated during one 'Otationat cycle The discharge from tertiary canals distributed down each offctaking flexi
Waler 'Works Deiwgn ana Supers sicn Fninrp isc
79
Ann: 2016M '’•stry cf Waler. irrgn or and Electricity Das-us Irrigation Study and □ca ge Project
Volume Vi rmal Operation, Maintenance anti Safety Manus'
Pam JI- Irrigation and Drainage System
flume in proportion to the irrigated area I he tertiary  canals  generally  run following tne contour stope in earth charnels with sub critical How achieved by droo structures, with the FS1 at ar a ide below ground ievcl At off take structure rocatrons the FSL is set to about 0.2D m above ground level, so that off taking flexi flumes can command ?heir head reaches Minimum embankment top width is set to C 50 m which expands as necessary to incorporate the 1:4 seepage path where the full supply  level rises  above the ground level, usually adjacent to cross regulators and drop structures Four meter w de un surfaced farm access track wrH be provided where necessary a'ong the tertiary canal alignment Excess water from field drains collected oy tertiary drains and disposed in to secondary drains or directly to natural gullies
5.5.      Operational Plan in Flexi flumes
Flexi Humes are designed to convey a flow of 40 l/s for 12 hrs each day, and the supply rotates to each off-laking fiexi f3ume m turn Each day. F low in flexi flume uniformly distribute
f
to irrigation fie ds on both left and right side of Flexi flume pipe outlets Flexi fume off take structure and chamber should be designed based cm rotating discharge The flexi flume capacity  is  determined by  the area of She farm unit But for the purpose of creating manageable velocity by farmers the design discharge o1 each outlet of the flexi flume has oeen taken as 0 080rrJ7s At the locations of the off taking points the field waler levels are set 0.10 rn above ground level to provide command for the fields Flexi flume Parameters and structure locations of fiexi flumes under the same chamber determine by using Flexi flume chamber calculation. As a sample; refer chamber calculation of QC-TCI -SCVLBMCin Annex 2
5.6 Operation and management of FGP (Flexi flume) for irrigating a field
Fo  efficient management of gated pipe,
r
the whole system shoo'd be installed with desired
recommendation Based on previous  experience of other projects  whrch used Flexiflume type canal, a three men irrrgatars' team is handling tne IQOhlfsec water for 20 furrows at a hme or 200lit/sec water for 40 furrows. Once the pipe is propei ly installed on the field the
rngators are expected to open and close inlet boxes and outlet openings of the pipe
■ By opening the gate of the inlet box, water from tertiary canal will be allowed to fill the pipe
•    Whenever water level m the irrigation canal fluctuates il car oe corrected by adjusting gates of inlet box
•    On average, discharge from each outlet should be 5lit sec
r
•    Check whether discharges or head difference of the firs* and last outlets is within the acceptable range or not
•    Discharge variation should be below 10% if tne variation is large, try to adjust the gate openings accordingly
•    By fitting a rigid and transparent tube having equal diameter on the pipe ouliels. vertical height of tne water raise in the lube can be measured
•    Discharge from outlet can be measured by Filling Known volume of container tor a specific lime.
WiilwWo’ks Desqr nnij SU3flrv<5 nn
35-
Aa-f. 20’cMmtalry al Waler, Irrigat or s d Elect ncity 
n
'/r.q.iiic' Study arc ten c- Project
Volume- Vil -Final OseraLson Maintenance and Safety Manual
_ _______ Parrt II- imgal'ian and Drainage System
•    When one side of a field is irrigated the number of outlets to be opened should be decided after evaluating nead or discharge var aton of the first and last outlets
•    To avoid erosion of furraw inlets compact firmly or use stable materials
•    To reduce discharge variability among outlets by compensating frictional losses, the required field stores for the pipe varies from pipe to pipe.
■ With the same procedure being done for siphon, in order to the desired amount of
water for the crop one furrow will be regaled for a specific period of time. For
example if rngation water is given every 10 days interval, the outlet will be closed within 40min; For 15 days interval. the duration will be GOminutes. IF every 20 days 
nterval, the duration will be EOrmrutes
5.7. Operational plan of Gates
A i machinery al the works should be kept clean, tidy and in proper wo rkrng arde  and care
r
should be taken to ensure that it is property handled in conformity with the manufactures' instructions. In this  project the main mechanics  items  are generally  the gates  and the winches
Gates should be periodically operated All lift gates should be operated at suitable intervals Io Free the mechanism and wash out of extraneous material, tn low supplies when openings are not desrrable. using of gales by 150 mm far a few minutes should suffice, if the gates have not been moved for a sufficiently long lime, they should not be forcibly raised all at once but should be lifted by about 30 mm or sa and left al that positron for about 10 to 15 minutes till the silt deposited agairst the gates gets softened and water beg os to ooze out This is essential to avoid heavy strain on The mach nery
The speed of operation ot the gates shouki be limited to the maximum speed indicated by the manufacturer. The operation shall be so done that the safety  of the structure is  not jeopardized at any  time is  not exceeded beyond the safe limit, which shall be clearly spec-tied
In general, operation of the main gates should ensure the following features-
•     The required full supply level is maintained both during the peak and low seasons
•     To evolve the operation of gates to exciuce maximum silt/debris deposits on the upstream side and also to minimize the entry of same in canals/channets
•    A relatively high intensity of flow is avoided in the deep scour zones, if tormed
•    Ma shoal has formed on eilner upstream or downslream or both of the intakes, it is washeo out and kept away from the intake, as far as practicable
•     I he canal gate operation schedjle should also consider constraints regarding rates of lowering I rising of wale' levels in the canal. It should also consider the safe rate cl tilling of the canals
I he following points should be considered during operation of gates:
•      The   discharge   tables   snail   ce   occasionally   checked   for   accuracy   by   actual measurements in the canal
Water W:--s Oeg gr ar*ii Suat’V s :j'i Erte'Srse
Aar. 7016Ministry of Water* Irrigation and Electricity 
Volume- VI -Final Operation, Maintenance and Safely Manual
Dabus >r-ga5cn Studyantf Dos-gn Project _ _______________ _______________ Parn II- tngat.on uno Drainage System
•    Mechanical gales should be oifed. greased and kept in perfect working order
•     Exposed  surfaces  should  be  kepi  property  painted  to  prevent  rusting  and  date  of painting marked on them.
•     Exposed surfaces which have beer recently painted should be periodically examined and any patches of rust found should be removed and surface painted.
•     The lifting gear should be properly lubricated to keep t in an easy operabng condition and  to  prevent  rusting  and  all  lifting  gears  should  be  properly  lubricated  once  a month
•      The  gates  and  lhetr  embedded  pads  should  be  inspected  during  closure.  They shouW be repaired, painted and Lbricated, wherever necessary.
5.8 Operational plan of Outlets
■ All outlets should be regularly checked and set right, it found defective, in accordance with the detailed .nslructicms ssued by the department.
•     Outlet pices should not be left lying about the canal. They should be carried to the nearest inspection house as soon as change in outlet has taken place and pipes are found surplus They should be slacked neatly
•      Water  courses  should  have  culverts/s»phons  wherever  needed  and  should  be property maintained to avoid wastage of water.
•      Register  should  be  maintained  and  head  of  water  (h)  of  each  outlet  i  e,  the difference between the water level in the canal and the center lire af the outlet at its exit end.  when the canal  is  running  al  full  supply  level  should oe measured every month ft win be of great help for ensuring that the outlets draw their authorized share of canal waler
•     T he outlets should tic so fixed that these draw their proportionate discharge/s It when compared to the supply in the parent channel.
Watt!.- W«rX5 De 5ig .1" r! Super v sinn Fnteransc
37
April 2^6Mn stry of Water, Imgatior ar-d hrectncity Pa nun irrigat'Ori Study a^e Design Project
Vo'umE-VII Final Operation, Maintenance and Safety Manual _______ Parrt 11- Irrigation and D-a nage System
6 INSEPECTION WORK OF CANALS AND DRAINAGE STRUCTURES
6.1.     General
Periodical inspection o4 canafe and appurtenant structures  is  necessary especially  before and after rainy  season to ascertain/examine their functioning The main purposes  of carrying out periodic nspection are
•    To ensure the adequacy of the structures to serve the purpose for which they were designed.
•    Tn verify the conditions of the structures and monitor their ber.avicr,
*    To nvestigate condnons that might cause distress to the structures, and
*    To study the extent of deterioration based an which maintenance and repairs can be planned
After an unusual event a thorough Inspection of the canals and its appurtenant works for delecting damage and weakening, if any, shall be made Adequate inspection shad be earned out by  competent personnel to investigate the performance of the canals  and appurtenant structures  All inspection observations  shall be compared with the design assumptions and prediction, previous results, results of model studies and tests and limiting values where specified Any conditions that might adversely affect the safety of structures shall be closely  observed. These shall include conditions  such as  excessive settlement, deflection, seepage, uplift pore-pressure, deterioration of masonry/concrete, etc
Inspection reports on the condition o* the structure shall be prepared and submitted by the Engmoer-in-Charge of inspection to lhe concerned higher authorities along with detailed comments.
The following is given a description of canals and dramage structures and their inspection related matters.
6.2.     Inspections of Canals
Whenever canal is closed for periodical inspection and repairs, lhe Im ng, ils-auxitiancs and special design features should be carefully inspected. The following points should be noted while carrying out the inspection
•     Whether any cavities or pockets have been formed behind the canal embankment and  lining.  At  places  where  considered  necessary  these  may  be  checked  by sounding the lining ties inspection of wet patches on outside slopes on regular basis.
•    Development of ary cracks or displacement or damage to canal embankment and lining;
•    Silt deposits and weed growth, and
•    Bench marks. Boundary pi iars, full supply water levels gauge at suitable mlervals be Pointed or fixed lo know about 1he hydraulic efficiency of the canal.
Wate’Wsrxs  Design  and Super s on L"temrse
■a
April. 2016Mims?/ of Waler, Irrigation arnj Etectneity 
Dabus rogation Study and Dwt»gn Project
Volurnc VI' -Fina Ooeralion, Maintenance an<3 Sately Manual _______ Parrg fl- frngajion and Drainage System
An accurate and systematic record of the performance of a canal should be maintained by periodic observations of manning's roughness coefficient, evaporation and seepage losses 
life and behavior of the lining adapted, surge wave heights, and performance of any special
□esign features ike pressure release system, provision ol humps or regulators, etc
6.3      Inspection of Canal Head Regulator
The work snail be carefully examined every year in the co'd weather by probing in case of u psi re am floor and examination under dry condition of downstream Poor 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 *.o five years by isolating the area All necessary repairs shall be earned out rn time
6.4     Inspection of cross drainage works
Cross drainage works shall be inspected periodically, the inspection shall be not less than twice eve7 year, at least once before rainy season and once immediately after rainy season. In addition, whenever a flood exceeding the design flood or the previously recorded highest flood passes the cross drainage works the structure shall be inspected to study the effects of the flood and suitable ameliorative measures shall be taken
Upstream and downstream Roods, loose aprons and niters, if any, of cross drainage works 'equrre particular attention during inspection. Any damage or settlement in them shall require specral investigation to initiate timely and adequate measures for restoration to avoid further damage during subsequent floods  I ikewise, training works  such as  groynes, flood protection works, spurs, etc. shafl also receive special attention during inspection regarding their stability and upkeep, so that any damage and/or settlement of pitching ard loose apron may not resjlt in shifting the course of tne stream and attack the banks of the canal and sides of cross drainage works
Inspections of cross drainage shall be directed to the following aspects'
•      To  see  that  the  coss  drainage  and  appurtenarl  works  are  in  good  operating conditions and to make them operable if they are not so,
•     I o determine after the floods the repairs or remodeling measures required;
■    Td see if any leakage from the canal s taking place at vulnerab e locations;
;
•     To nvesttgate for presence ot any unusual phenomenon n respect of boils, piping, sweating of bank or saturation of substratum etc or cracks n the structure.
•      I o check any changes in the design features in the field and io restore it to the original  design  and  to  redesign  the  hydraulic  slructures  after  the  floods,  if  so warranted,
•      To  study  the  behavior  of
pressu e
r      relief  valves,  weep-holes,  ard  biters,  if
any,
installed in '.no floors/rctaimng walls of cross drainage works,
■    To  study  the  water  levels  recorded  and  the  quantum  of  flooc  discharge  passed through   the   cross   drainage   work   for   evaluating   its   performance,   (n   case   of excessive rise of levels, investigations have to be earned out and remedial action
■A'.i'c’ Works Design a a
-
S..PC V s an Enlern*-
3-1
Aon' 2016M.nislry of Water. rngaton and Electricity Pablos '^ligation Study ar a Oes:gr Project
Vnli.rre- VII -Final Operation Maintenance and Safety Manual Parrt ii Im^aHon and Dra^ggc System
taken In improve the conditions, if necessary, also during canal closure If it is due
Io blocking of passage, the works may have to be de-watered for inspection; and
•       To  study  the  longitudinal  section  of  drainage  to  see  whether  aggradation  3rd degradation are taking place, endangering lhe safety of the structure
In additior to the above, the inspection shall include ir.vestrgation of the following aspects to guard against damages occurring '.o lhe cross drainage work:
•     Investigate if any meandering of lhe drainage channel in the vicinity uf the structure or change of flow pattern has occurred during the previous rainy season period
•     Investigate whether new streams have been diverted mto lhe main stream for which the  work  has  been  constructed,  resulting  in  inadequate  capacity  of  lhe  cross drainage work,
•     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  the  cross drainage structure]
•     Investigate whether the tanks on the upstream of the structure are in good condition, and
•      investigate  the  construction  of  bridge  or  other  structures,  with  fewer  waterways, which may increase the HFl_ as a result of afflux
6,5  Performance of Structure
The performance of structures within thrs project shall be evaluated as below
Suspended sediment.
During Lhe rainy season, water sample should be taken in accordance with IS 4890' 1968 simultaneously upstream and downstream ol the under sluices and in lhe canal below the head regulator to assess lhe suspended sediment there in such observat ons should be taken at leasl once a week (closer ntervats in case of high 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 deckle 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 superirnposition of old and new survey. The changes In the nver course shall be examined and remedial measures should betaken.
Aggradations upstream:
Inc river bed upstream of the dam is likely to aggraded resulting In increased afflux and reduction m freeboard provided in design To determine the increase in the afflux, if any,
gauges should be established on the upstream, one immed ately upst eam of
r
the work and
one each al 500 m and 1000 m upstream of the first ard observed regularly. The necessity of fasmg/consuuctirg any afflux banks may have Id be considered to restore the desgned freeboard
'Wale' Woms Design arc 
!r
5jQP. v>S o Enterprise
r
35Ministry o' Waler, Irrigation and E ecZncrty 
Dabus i*riga1ron Study and Design Prpj«ct
Discharge distribution and cross-flow;
Vo iw VII F nal Operation Maintenance and Safety Manual
_
Pam II - I'rngatipn ano Oa nage Sys fern
For head and cross  regulators, observations  should be taken to find the discharge dist-ibution through different bays  of the intake If there is  significant cross  How and/or difference in discharge intensities  through different hays, remedial measures  should be taken to check this tendency tor which mproved regulation may be a great help
6.6.     Flow Rate Measurement Devices. Methods and Regulators
6.6.1, General
Measurement of rate of flow of water is essential for proper water management in Irrigation agriculture Mainly it is essential to ensure equitable water distribution among farmers based on unit area 11 enables farmers ?o schedule the contact duration in irrigation, and to monitor water loses. Hence the volume of water has to be measured at key points like head works, the mam conveyance, turn outs, tertiary canal off takes and field intakes.
Discharge observations or mam canal and branches shall be carried out al least once a month during non-rainy seasons. During rainy seasons discharges should be observed more frequently for major 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 rn the mam canal 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 The design of Dabus irrigation system is developed with the hydraulic principles related to flow of waler Therefore hydraulic structures ano canals are also useful for measurement of flow and flow proportion
Discharge measuring sites should be fixed at suitable points and may preferably be in the form of fiurr.es falls  or straight runs  of lined section All discharge observations  should conform to relevant Standards.
Gauges at the head and tail of all the channels and at important points in between an long channels should be observed and recorded daily.
6.6.2.  Auxiliary Equipment and structures for Measuring Flow
Some wale^ measuring devices and structures that are used for measurement of head, h. or pressure, p, to detemnine discharge am
•    Rectangular weir. V notch, Broad Crested Weir, Sharp crested weir and Parshal
flume.
•    Cjment Meter
•    Staff gauge.
6.6.3.  Methodology
Tg  evaluate  the  possibility  of  establishing  eve!  recorder  staffs  within  the  system,  their modular properly under dcsigr and operation 1'ow conditions in lhe parent and off-taking
Wale- Wsrks Desiqn and Sunc^v s s" Erne-er sc
April 20*6•Vimistry at Water trrtflaUon unit Electric ty Dabus Irrigation Study and Design Prated
Volume- V!< -Final Operation. Maintenance a rd Snfoly Manual
___________ F’ar11 11 irrigator, and Drainage System
canals should be known. These properties could oe studied from detail design documents After studying their modular property flow can oe measured by fixing level recorder stall. In- addrtion, to fix the level meters and to develop reasonable stage-discharge rating curve, field work should be arranged to carryout the following works:
•    The best representative structure to measure the intended flow wi<" be selected.
■ The actual level and dimensions pertinent to discharge calculation will be measured. *    Calibration wil be conducted by taking records of actual heads and discharges
6.6.4,  Flow Measurement in Turn Out
The flow measuring devices of the Off Take (OT) structures from distribution canals are types ot measuring structure that measure head The flow in Off Takes (OT) is based upon Orifice relatiansNo. For a circular shaped orifice the continuity equation (or discharge Q becomes:-
Q=C Bw '2gyi
5v
Equation 6,1
Where,
O - the discharge in m’/s,
y v- the entrance water depth anove the sill or floor in m,
B: - the width of the gate in m.
W ■ the openrig of the vertical gate in mr
C  - the discharge coefficient. The discharge coefficient C  should be calibrated
according to site condition
6.6.5.  Flow Measurement in Regulator
The flow measuring devices of the Regulator structures of mam and secondary canals are types of measuring structure that measure head t he same orifice 'omula is also applied (or measuring the discharge.
6.6.6.  Rating curve
Based on the evaluation method explained in the above section rating curves, a stage discharge relationship used fo the measurement of discharge of Head Regulators (HR) of
d
a
r
both eft and right bank side secondary canais and right bank side tertiary canal a e
r
developed. For the Petal of each rating curve refe ANNEX 3
r
Waterworks Deygr anif
Aa-r 2C;tMinistry oFWltar Irrigation and felcclr r, ly 
(
Ir 9aE °2 stugy a^d Den gn Project
Volume- VII —Flna' Operation, Maintenance arc Safety Manual ______ ____  ParrL II- irpgalion arc* Drainage Syster’
6.6 7 Discharge Regulating and Controlling Canal Structures
The main discharge regulating and controlling canal structures of this project are:
a Gales
d Water measuring structures c. Drops
d Division boxes,
e Cross regulators.
Head regulators 
g Siphons
h. Cross drainage structures. i    Escapes,
Wale - Worsts De* and
Suge^v 5 :nn Friers? sti
Aanl, ?n-6V  n  sky  a.  Wa:er  'mgatiofi  .lid  Eleckioty PatHiS frdgal cr Sludy and Pes gr Pro.ce^
Volume- VII - rrai Operation,
nance arc Sataly Manual Pant I- Irngamn am Drain nijp System
7 MAINTENANCE OF THE IRRIGATION & DRAINAGE SYSTEMS
7.1. General
Good management, efficient operation and well executed maintenance of irrigation and drainage systems are essentia' for the success and sustainability of irrigated agriculture The objective o' maintenance is Io keep or restore the technical infrastructure in the condition *t was in when t was newly built and to ore vent or reduce the effects of unexpected events.
Cause of damage to the irrigation and drainage system obviously is due lo the human and animal interference in the natural environment, which could be indirectly by destroying the natural environment or directly  by  destructing the irrigation infrastructure This  causes excess flood laden with silt, whrch cause destruction of projection embankments, breaching of canals, growth of weeds and other unwanted plants in the canals, cracking in the canal structures, etc  These a’l reduce the discharge capacity  of canal, which intern affects  the irrigation management The efficiency and longevity cf the scheme lies upon the nature of maintenance of the components  involved in the irrigated agriculture and uokeep of the general ecology and environmental maintenance
Maintenance involves  clearing and repairing canals  and drains, repairing structures  and canal I ning and cleaning and lubricating gates. Regular maintenance of the irrigation system reduces repair costs, help the system last longer, and Keep irrigation efficiency at design levels Efficient water use requires simple, but ongoing maintenance.
Principal arris or regular maintenance are:-
•    Repair damage to prevent deterioration of canals and structures which would
otherwise require expensive rehabditalon
•    Allow the system to operate satisfactorily supplying all pans of the command.
■ Maintenance should be preventive, to solve problems before they become major
works.
Some ol the most common consequences of poor maintenance arc as follows.
Mechanical failure andinoperaoiliitycif gates and valves;
I cakage from canals,
Silling up of canals.
LJeteriarat on of concrete lining and concrete joints:
Erosion and silting up of field ditches:
Washouts and bogging of roads that make access to parts of the system difficult, and
• Silting up of drams as wc i as blockages and fat ure of drari<<
7.2 Categories of Maintenance
1 he repair and maintenance of irrigation category
W«lr.r W: -s Des t|n arc S ;ocrvis>Dr z":e*pr M1
39•Vi> stry of Water, rrgaLinn and Etectr City Oahu* Irrigation S‘udy and Or sign project
Volume V'l-Fma' Orenlion. Mirnteranee and Safety Manua- _____ PaM ii iligation and Dfa'.nagc System
•     Regular: - it is done regularly at intervals of week, month ar al the end of each crop season and beginning of ire new crop season It is done without any hindrance to the performance of the system
•     Periodical: - 11 is done once a year before opening of the canal and also at the end
□f the canal closure and is done during non-crop season
■ Special repair. - It is done when some extra ordinary repair is needed In this, extra cost is involved in addition to the normal repair maintenance cost, such as changing of trash racks renovation of structures etc
•      Emergency  repair  -  This  is  done  after  some  emergency  probtems(   like  canal breach,  structure  damage;  gale  jamming  etc.  take  place.  The  conveyance  system has to be closed for attending to such repairs
•     Organization: - This has been laid down sn this manual under chapter 9 The same group of persons will be ooerahve for repair and maintenance of the different system.
Note:
1. As built plans, maps and drawing prepared by the irrigation agency will be provided to the WUA. which will assist :n estimating maintenance cost prooer operation and maintenance
2     The  patch  repair  works  in  the  masonry  or  concrete  should  not  be  done  with material of lesser strength than that classified rn the original work
3    Any settlement, crack or damages are to be properly communicated and technical advice taken for setting ways and means of rectification
7.3.     Maintenance Activities
Regular maintenance activities: - have to be repeated throughout the lifetime of an irrigation scheme to keep it functioning. Some of these activities are daily routines which do not require speoa sktrts. Regular maintenance is  probably  the most critical and cost beneficial type ol maintenance activities, since small repairs identified early and carried out Quickly will stop more major deterioration or problems occurring With effective planning and implementation, regular maintenance can reduce the need to spend scarce funds on major repa rs ata iater date
Some typical regular maintenance activities are as follows
For irrigal'on and drainage infrastructure
•    Greasing of gates & valves
•    Painting of metalwork;
•    Devilling of field ditches and repair of ditch banks
•    Cleaning of drains;
•     Repair ol access roads and minor earthworks:
•    De-siltng of small irrigation canals, gated turnout structures measuring structures;
•     Grass cutting and vegetal on removal
WatB- Wa/k.'i Dll sign Susc’vis du Erterprse
I PS 6
-s jy nf WnLer.
r
Ir'igatci* artd Electro?/
Volume- Vil -F nal Onnralion Maintenance and Salely Manual
Dab js I rogation SI Lrd^a nd lOesig n Project________________ _              ____  Fam !l fixation a nd Drainage System
Periodic maintenance activities: - require skiJted artisans such as a mechanic, a mason, a carperier and a painter it consists of repairs that are too Jarge to be undertaken at any one time during the seasonal delivery of waler For this reason, these repairs must be planned for those times  when the Irrigation system is shut down. Some of the maintenance tasks should be dore yearly  as  oart of good O&.V management procedure Others  can be conducted half-yearly depending on cropping oalerns and crop-irrigation requirements.
Typical periodic maintenance activities are as follows:
•    Repair, cleaning, and de-silling of medium and large irrigation canals;
•    Repairs to gates and measuring structures;
■ Repainting of steel structures
•    installation of water ‘evel gauges.
•    Programmed replacement of gates and valves, including their seals or slides
•    Programmed reforming of f'exi flumes, on-farm canals, and in-field ditch profiles (to
be done by farmcr/water users under the supervision of foremen);
•    Cleaning and de-silting of sedimentation pords. large turnout structures, and
measuring structures.
•    Repair, cleaning, and de sitting of surface drainage systems that cannot be done
during the irrigation season, and
•    Removing trees and saplings from adjacent to the concrete lined canals through
cutting and poisoning
Olher  penodc  maintenance  activities  that  are  usua.ly  done  between  irrigation  seasons, when the canals are drained, are
•   Major repair or replacement of gates,
•   Large-scale silt clearance from canals and drains;
•   Large-scale maintenance of roads and embankments
In the off-season, both farmers and operators are not busy with irrigation and can therefore be more easily engaged in maintenance work.
Emergency maintenance activities:- require immediate and joint action by irrigation staff and farmers, to prevent or reduce the effects of unexpected everts such as
•    Breach or overtopping of canal embankment or river dyke, causing flooding;
•    Critical failure of headwork, causing interruption of irrigation water supply;
•    Natural disasters sucn as floods, earthquakes or typhoons
Operational staff must be trained so that they know what to do as soon as they arrive on the scene. A good communication system can do much to reduce the damage
Wate^Wa^S  Des'gr  a  rd SjperviaiGn r -’!c^- -,r
Aonii. 2D16Min-itry uT Water. Imgal ar and Electricity Dao us • jjalicn Study urd Des gr Project 7,3.1. Bed and Berm
Volume VI -Final Oocration, Maintenance and Safely Manual
______ __ Pair! II- Irrigation ard Dra nage System
Bed ano berm shall ce 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 properly  Before starting work  on either lhe bed or berms, they shall be aligned by flags  and string The former are necessary  for lhe alignment in general and the latter to correct small irregularities  in that Every  opportunity shall bo taken lo 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 'all
All grass shall be scraped and weeds removed from the silted bed wherever they are found to exist smee their presence induces silt deposit.
All local accumulations or continuous deposits or mounds of silt shall be removed Io correct bed level Beds  snail oe leveled and their gradients  regularized by  the removal of silt mounds and all mounds higher lhan correct bed level Bed levels shall be fixed correctly al close 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 snail, however, be cleared to lhe con-ect trapezoidal section The practice of cutting the silt deposited at lhe junction of side slope and bed and throwing it on the bed lo level it shall not be permitted
Note: - It will be desirable to prepare a longitudinal section of main canal canals during closure once a year. Cress-sect ions should be taken in reaches wnere the section is over wide or too much scoured The behav.orof 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 Fngineer in charge.
Berm cutting shall not be started until sample prof.les nave been cut and the lines carefully laid Where earth is  required for repair of banks, berm pockets  may  be made Irregular protruding and overhanging berms shall be cut back to proper aligrvnerl and slope, if this is neglected berms  fall in or protrude abnormally  and the canal tends  to adopt an rregular sectron 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  egutar
r
trimming  and scraping as  the  situation calls  for
every year
7.3.2. Escapes
An Escape structure is provided on the cans. bank or at the end ar canal (called turnout gate) at suitable location Io release surplus waler from main, primary or even secondary canals  Surplus  water at a particular point in a channel may  result in following circumstances
Warkii Design and Suec’v i 2’’ trlirronse
Ann I 2016MinrB-try of Water .Irrigation ann Electricity Uatius Irrigation Slucty and Design Project ___
Volume VII —Fins' Ocesitiori Minnterarce ancf Safely Manual
_      ___  Pirrt II Irrigation a rd Drainage System
•    Mislake or difficulty in regulation of a long canal
f
•    For evacuating a canal for occurrence o any breach in the downstream and its rectification
•    Sudden closure of outlets by cultivators
•    Excessive rainfall in upper reaches and particularly when an inlet structure is closed
Escapes shall be kept ctear 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
7,3.3. Silt 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 functionrng 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 theo'et'.cal cross section on runoff the nver canals and specially those which arc also run for paddy irrigation silt is likely to deposit m distributaries and minors wbrch may get picked up when clear water runs In the channel after rainy season Longitudinal sections of silted bed of such channels should be taken during closure
Immediately after rainy seasons and the gradient at which silt should not be cleared below falls but if outlets in such places are overdrawing water due to rise rn water surface, they should be raised Boning rods shaukJ oe used to see whether the siit has been properly cleared. As soon as a canal is closed for a fairly lang period the bed bars shall be uncovered and the depth of silt over them recorded
7,4. Maintenance of Embankment
Proper maintenance of embankments is extremely important as breaches in them can be disastrous  and may cause ever greater damage lhan the rnundation by floods where no embankments arc provided.
( he maintenance wirk may be divided rn to two parts
a)  Pre rainy season maintenance
b)  Rainy season maintenance
a) Pre rainy season maintenance
Existing embankments have to be repaired or reconditioned to the original design sectton m advance for their efficient pedormance during the ensuing rainy season The free board may bo checked uo tor any rise in oed level of the rrver or other constrictions which may result in bigner design flood and prov.ded/ rna ntained accordingly
All  hollows  and  depressions  in  the  embankment's  section,  wherever  existing  should  be made up with rammed earn after clearing the site of loose earth and vegetal materials
Water Wo’ks Dcs»gr an c S-pcv a m Enternftse
43
Apr.) I'LIGMir ~:ry of Waler, irrigation and Electricity 
Vs'urrie- V?l -F rut Operation, Mamlcnar.ee and Safely Manual
□nbu* kr-gabon Study ard Des gn Project ____________  F*ant II- Irngatian ano Drainage Synlern
Where the tap material jssandy or silty, it is desirable to provide a cover of soil containing 1D 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 oeriod The leaks, which ecu d no! be fully treated during the rainy season, should be attended to Immediately afterwards Such leakage sites should be opened in full width of the embankment taking care Io trace to its uostream ends, and then be refilled, watered and rammed, the old earth being stepped or benched back at sides and new earthwork properly bonded and interlocked into the old
Rodents and other animals make holes, cavities and tunnels through and under embankments are source of danger causing leakage and excessive seepages which may give rise to serious breaches during flood period, Such holes should be carefully located examined, provided with an inverted filter, filled with earth and ammed. Alternatively such
r
holes should be filled with weir rammed sti*f clay.
All the masonry works should be carefully inspected to detect if there is any danger ot seepage of water along the olanes of contact between the earth and masonry The ear:h adjacent to the masonry work should be laid in 15 cm layers, watered and compacted, brought to the design section
i or embankments which were severely threatened by erosion during the previous rainy season, revetment/r prop or other river training works should be separately exam ned In case of wave action, pitching may have to be provided 30 cm above the water level rn tiood
Approach roads  and also lop of embankments, wherever they  are designed to carry vehicular traffic, as well as ramps provided for inspection so far they serve the purpose of transport of malenaSs and inspections both during the pre rairy season and rainy season periods:
•    No habitation should be permitted on the emoankmems
•    AU departmental vehicles should oe kept operational.
•    All sluice gales, valves are kept greased, oiled and treated, if provided
•    Ail tools and equipment including torch lights, lamps, spades etc and flood lighting articles as wel as materials (or erecting temporary sheds at the work sites for workers should he arranged and stored at suitable places.
•    Proper communication system should be installed before onset of the rainy season. b) Maintenance during lhe rainy season
During the rainy season, prompt maintenance of the embankment is required as the flood water of nver threatens the safety o* the embankment mostly during this period This is ail 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 ol the river As  the nver touches  the embankment and river snows rising trend, round the clock patrolling should start by staff
Wb'e- Wprks □es’3’1 end
Suac'v 'b'an E-riera - sx?
Acr 7'/ibf
Mm irry o Water, Irrigation and Electricity 
Vo.'u-ne-VII -Rnal Operation Mn nienartce arc Safety Manual
Dabus knga«ion Study and OcsrgnPiQjecl __________ Parrt II- Irrigaicn and Qra-nj-gc System
engaged for Ihis  purpose and continue till water finally  recedes. During Ibis  period, nspect on of senior officers should be earned 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  boil formation due to seepage This should be immediately attended by providing loading berm to counter balance exit grad ent A suitable filter material may be placed around the beil below the loading berm Io arrest fines in seepage water
To prevent the water from overtopping and washing out a portion of She embankment, a dowe-’ of half sand-filled bags at the riverside and at the top of the embankment may be provided Reparr of rain 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. Rood disaster can be reduced to a great extent All mforrnalron connected with rising flood water level and flcod situation should be passed on to the concerned higher authorities to enable them to take safety measures in time
7.4.1. Banks
Barks 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 Standard
Before conL'nuous bank repairs are started, profiles shall be made at about 1C0m apatt These shall be at the correct height and width of the bank reoa red and shall be checked before work is started
All noies and ram cuts shall tie fully opened up to the bottom by digging steps not more than 0.5m deep in the sides and removing all the 'alien or loose :umps of earth, bushes, grass roots, etc Filling and repairing shall be done by placing level ayers of earth (not more than 15cm deep) I he earth in each ayer should be free from eleds. roots, grass, brickbats and other debris and t shall be compacted at adequate moisture content
Leaks shoud be slapped from the upstream side by cutting off the penetrating water. If praclicabte cracks should have good earth worked into them by chisel pointed poles, but if the presence ot water against the bank prevents Ihis. the leakage should be stopped by a cover of good earth thrown over it. Subsequently, in dry season the detective 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 slope of about 1 in 50 In order to take the ram 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 reaches and regular on curves
Both  inner  and  outer  slopes  and  toes  of  banks  shall  be  free  from  irregularities.  Only projections shall be cu dawn and earth thus ohtaired should beutiiized in filling hallows.
Loose earth shall net be left ly nc on top of a bark Wherever Tilling is necessary, t shall be well comaactcd Grass or turfing shall not be scraped t should only be cut as far as
WutC' Works Di'5 g-! arc 
S. ce'v-s nn I r'emrse
A*nl ?U1BV nstry □[ Wale* Irrigation and E ectf Icily Dators Irrigalior 5'^-jy and Design Pro;cd
Volunnc-V>' -r naJ Opera-jcr Ma. He nance and Sa'ety Manual Perrt II- Irrigation and Drainage System
necessary tn show the surface of the bank and to avo;d the boles being hidden under long grass Scraping lhe 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 irregula by developing unwanted bulges and holows
r
1
The top of both banks sha ! always be kept smooth and Iree from holes One bank, al least should be maintained as an inspection bank
Banks that are too low should be raised to lhe proper design levels as early as possible In previous 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.
7 5. Vegetation Growth
All vegetative growth on canals, distributaries and minors should be cleared from toe to too of lhe outer slopes of the banks Shrubs, large grass, small trees, etc. should be dug out by roots Stumps of trees that have been standing should be cut down to al least below the ground. Ant hills shat* be dug out and leveled off All vegetative growth on escapes and drains should be cleared from the outer edge of lhe inspection bank to Ire inner edge of the opposite bank
ThE surroundings of chain age stones should be kept clear of jungle, grass or any other
rubbish to enaole them to be seen from a distance Io save maintenance money and
enhance income, grass can be auctioned after 10 days of the first rams of the rainy season
and many cut may be permitted
More details  of all the drains  discharge and dimensions  etc  are given in appcnoice; of Dabus irrigation and drainage design report in order to maintain the design parameter All the drams are bebw ground level for easy fluwof drainage water
i he inspection bank should be maintained in good condition. Silt cleared from the bed of a drain should be used to Till up holes and ruts on the inspection path / raise the canal banks/ service roads This silt should not be thrown up in drams
Trees should not De allowed to grow on lhe inner slopes of drams. The dead brarches and rubbish that may nave accumulated in the drains should be cleared before the rainy season breaks Bunds should rot be permitted in drams and should be removed if found existing before rainy season breaks Discharge of drams should be observed each year at suitable points and recorded in a register
7.6.  Roads and Ramps
Roads and ramps shall be kept smooth and shall have a regular longitudinal grade Ramps and approaches  to hedges  should be maintained smooth and to lhe designed gradient. Where there are spoil banks an the side of the roadway and higher than il there shall always be a continuous dram along the outer edge of the road as well as cross drams through the spoil barks the latter being at right angles to the former and fading with a gentle sloce to
Wate' Wurks Des ="d
■‘-6
Ap' iM  nistry  nfWale'  Irrigation  and  Electricity paflusjrrigation Study and Design P gfecl
f
Valurne- Vll ——.nal Operakpn, Mamie nance a nd Safely Maftua
______  Parr*. II frrtgaLian and Drainage System
the boundary ditch. Cross drams shall not be allowed to gel 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 bridges, side drain along dowel (earth in parapet) should be crowded.
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 stores should be adjusted and white-washed While undertaking any repair work on service road suitable diversion shall be provided co allow uninterrupted traffic during repairs
Ordinary repairs to Ganal roadway should bo taken in hand after first heavy rain falls and should never be postponed till the end of the rainy season.
The canal roadway should be inspected after heavy rain and holes where seen shall be filled Silt from canal berm may be used for closing these holes whe e there are no spoil
r
banks  Holes  generally  result  from  defective  drainage  which  should  be  looked  into  ana remedied otherwise lhe holeswill quickly re-open
7.7.    Maintenance of Furrows
After construction the furrow system should be maintained regularly  along the entire irrigation season It includes, minor earthworks  !c  maintain the furrow discharge and 1o prevent breaking of the furrow wals or elevated bottom, causing spillage of water,
□unrig irrigation if should be cheeked if water reaches the downs! re am end of all furrows There shouta be no dry spots or places where water stays pond ng Overtopping of ridges should  not  occur  The  flexi  flumes  and  drains  snouid  be  kepi  free  from  weeds  Such maintenance is carried out by the user conbnuously during the irrigation season.
7,8.    Maintenance/ Repair of Flexi flume
•   Majo' leaks or tears can be repa red by slid ng a 12m length of fluming of the same diameter over the damaged area or
•   By joining a shod section of rigid pipe of the same diameter.
•   The tube should be laid out peroendicuiar io furrow direction.
-----~l
J
lURf SlEE/E
.□Wlfj
Figure 7.1  Fluming repair methods
Wate'Wc'-i Design and Sjoen/5<v ^'-rr’fnrse
Atj-i 7016IV i sir v Water Irrigation and Electricity Datnis '-ngai-on Study J nd Design PrO;ed
7.9 Maintenance of Earthen Canal
Volume VJI-Fina; Operation Maintenance and Safety Miinua s’arrt II- irrigation and Dra "age Syulern
The earthen canal overall maintenance should tie done at the beginning of the season when the canal Is free from flow of irrigation water This is done just after the rainy season before the start of irrigation It consisls of weeding, de-siit'ng, re-shaping and executing mnix repairs But minor maintenance like clearing of weeds and bushes from canal embankment should oedone repeatedly based on lhe problems occurred
•    Bushes or weeds on canal embankments should be removed
■ Silt and deeds in the canal should be removed. While cleaning the canal bed. care must be taken that the original shape of the cross-section is kept The silt removed from the canal bed should not be dumped on the canal embankment Place sediment in a disposal area or, if aporopriate, mix with dry soil on the site to fill low spot *ields.
•    Breaches and animal hoes in lhe embankments should be filled with compacted soil, ms de as welt as outside of the embankment For compacting, the soil should be wetted
•    Weak sections and sections o' the canal embankments where people or animals cross the canal should be strongtheneo with compacted soil
•    Eroded sections of the canal should be rebuilt to lhe original shape.
7 10 Maintenance of Structure
7 10.1, Generai
Different types of structures are essential m any irrigation and drainage system to effectively and efficiently convey reguiale and drain the flows and to protect lhe system from storm runoff damage For Dabus irrigation project, the hydraulic structures nave been categorized as in line canal structures, regulating and protective structures The in Ime canal structures include all canal structures like storm water crossing, canal siphons, falls, and road culverts. The regulating structures are cross regulators, head regulators, pond intake & escape structures or Main canals The structures dividing the flow in secondary, tertiary and field though regulate the flow in a broader sense but have been termed as  flow division structures These structures can also be used as flow measurement structures provided ratings  curves  are developed *or ease of operation, The protective structures  which externally  protect the canal from storm waler have been referred as  cross  drainage structures and the structures which internaSly safeguard the canal from the excess canal watcr have been named as escape structures. The cross drainage structures would direct the storm water runoff either under the canal or aver lhe canal.
As mentioned above most structures associated with Dabus rrigation project are utilized for conveyance, regulation □ rd control of water. It contains  both structural arid hydraulic features and rs generally constructed in concrete masonry, metal & rock
Precautions and remedial measures those should be taken fer the sustainability of structures within the project are
Wj:c’ Wonts Design and SLCerviBian E"?flrp- i5e
r
April 20'6M nislry ol Wa!er Tr gal on and EleC.riCijy 
Volume- VIt -Fnal Operalion. Mninlenance and Safely Manna
Uaous Irngal on Study and Des-'gr arc;ecl __________________________  Pjarrl II Irrigation and Drainage System
•     All  masonry  structures  should  be  mamtaired  through  proper  repairs  i  n  a  sound condition  Any  damage  noticed  in  these  works  should  be  speedily  rectified.  Care should be taken to ensure Draper curing of repair work.
•     No grass should be allowed to grow near the parapets or wings of canal structure which sho jId be kept scrupulously neat and tidy
•     Metalling  over  bridges  and  eadbwork  in  both  minor  and  major  ramps  should  be complete and well consolidated everywhere
•     Ramps  tor  bridges  over  canal  should  be  maintained  n  proper  condition  so  as  to ensure the canal hank is not encroached upon
•    AH drainage crossings, downstream of canal structure where significant canal erosion persists   due   to   turbulence   of   the   wave   action,   dumped   riprap   consisting   of gravel/small boulders should be provided
•      Protection Dy launching apron should be provided only in a length so as-lo cover maximum scour in a slope of 2:1
•    Dumping of boulders should not be above bed level
•    r mbankments should be protecting by pitching on the side slope with stones.
•     Stones  left  out  protruding  in  a  staggered  fash  on  will  be, helpful  in  dissipation of energy  However,  if  this  provision  does  not mprove the situation,  the  cause should be investigated  and  suitable energy  dissipating  device  provided downstream  of the can a structures.
•     Scour  charts showing the depth and extern of scour  should be maintained for all major canal structures where this tendency persists. The charts should be re plotted and rev sea at least once a year after the annual closure
•    Grass and bushes should not be allowed to grow on the structures; it snouid be dug
out by roots Slime and Moss which often coat masonry structures should be
careful.y scraped off. care being taken not to injure the mortar or plaster in doing so.
•       o the register, the drawings Df all the masonry structures arc maintained and kept in site office and re-modeling or repairs, etc. earned out from time to time, are marked m different colors and note to this effect rs given on drawing, so that the relevant case and document could be linkeo
The project Water Management Committee (WMC) is provided with list of all the structures and as bu It drawings, which are helpful while the operation and maintenance activities are carried out
List of types of structures within the project arc
•    Diversion weir
•    Head Regulator
•    Night Storage reservoir lined with Gen membrane with appudenanl structures
•    Conveyance & distribution Systems
•    Turn Outs MG to SC. Sc to res and Tc to FFs
•     lailEscaoe
•    Division box TC
'ZJii'.e-*- Winks Design and S^pi* / s 5f ertdrprisp
n
Aori*. 7 ’ • 5Mtfl-s’ry  ofWaler,  Irrigation  arc  Electricity Dab-s krigalion Study and Desjgr r-qtci
•    Drops
•    Cross drainage culvers
Va ume- VII Final Qae'gior. Maintenance and Safely Manual Parrt ■ Inigaiion and Drainage Sjslern
The general outines of maintenance for the above list of structures are as follows
A.    River Divcrsion^Hcad Work:
■   Weir crest and toe Repair and Maniain periodically after rainy season.
•    Downstream Apron Repair and Maintain periodically after rainy season with gabion or other protective materials.
•    Abutment walls Repair and Maintain periodically after rainy season.
•    Abutment foundation Maintain the scoured toe from failure of the wall
•    Under sluice \Head regulator Lubricate by greasing or the vertical shutters arid hoists.
■   Abutment weep holes. Remove clogging for discharging saturated water from the Backfill material.
Repair wo ks ir the masonry or concrete shall not be done with materials of
r
lesser strength
than that classified m the original work.
Ary settlement crack Dr damages are to tie properly communicated and a technical advice
is taken for setting ways and means of rectification.
E3. Conveyance and Distribution System:
•     Main cana . Secondary Canals & I ertiary Canals, Periodic removing of silt dcposil for effective conveyance & Distribution of the required water at the beginning of each irrigate on season
•     Bed and side slope of canals are maintained whi’e checking the profile based on design
•    Height and width of banks of canals shall be maintained against over topping
•     For  cross  seebon  in  the  cutting  reach  protective  measures  to  be  taken  against erosion
•      Interceptor/cath dram to be kept always free o’ silt and other material clogging the way
•     Crass section in the fill zone, Sloughing of outer slope or seeoage can be prevented by earthen materials dredged out from canal is to be added as a cover.
» Crack or Leakage in banks, during canal closjrc by taking out damaged pohion and comoact with selected material.
•     Staff gauges, To be kept oainted and kept clear
•    I low measuring structures Appropriate Technical help required for effective repair
•      Conveyance  and  distribution  structures;  Appropriate  Technical  help  required  for elective repair.
Water Vj.:Des si- a~5
SteHi'yisiur E mc'pnse
Ac-1 TC'GVirwy DfWatxr. Irrigation and Eiectrlcty Tabus Irrigalion SMdy and Desig" Proiecl
Volume-VII -F *ial Op&ralion, Ma ntenar.ee and Salely Manual Pjrrr If- imgaticn and Drainage System
■   Downstream 'foor and cutoff portion of structures by filling it with packed boulders and rirving is done to protect Retrogression.
•     Seeping reaches of the canal, Lmirg should be provided during closure of the canal
•     Cross sectior and slope canals; Always to be maintained since .t affects equitable water distribution
■   Weed growth n the canal/Dra^n; Remove periodically since it reduces the discharge capacity
•    Turn out gates; Lubricate by greasing of the vertical shutters and hoists
7.10.2,  Maintenance of Lined Portions of Canals
In case o' Dabus large scale farm project, masonry lining will be provided in small reaches only, if required from the consider al ions of the seepage in 'weathered rock area A ‘med canal should be maintained so that it continues  to function efficiently  and serves  the purpose, for which it has beer constructed, throughout rts effective span of life. In addition to maintaining its im perviousness, 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 had when 4 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 lhe drainage, growth of weeds, algae and moss; seeuage and evaporation etc
fhrre  can  be  drstress  to  the  lining  ranging  from  small  settlement  cracks  to  excessive heaving dsplacemert and sinking of the I ring in lhe following situations.
■   Cuts m soft fine grained soils, especially when the lining was laid directly on the soil without any specra preparation of the sub grade,
•    F- reshly lard embankmer is. especially if composed of clayey soils,
•    High continuous spoil banks, left loo near the canal excavation wrthoul sufficiently wide berms and adequate arrangements for draining the ram water away from the canal;
■    Cavities behind lining caused due to sucking out action on sub grade material by oscillalmg waves or fluctuating supplies of water of the canal through cracks, open iOinls and holes in lining, sjch action as may be necessary to avoid recurrence of any failure In the lining should be taken by investigating lhe causes of the failure and remedying lhem 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 oe carefully packed with sand or other suitable material Care should be taken to ensure !hat the lining does no! get damaged or displaced during the operation,
Damaged or displaced portions of inirg should be removed and replaced by fresh lining of quality comparable to the original lining i ho sub-grade should be thoroughly compacted
and prepared m accordance with IS 38 73. 1992 before laying the fresh lining The cracks (other than hair cracks} should be filled with bitumen or other suitable filler so as tn ensure
water tightness of the lining. A mere effective sealing of cracks may be obtained by cutting a
Wa!- ' Mrks Ctesigc ard
-
51
Si.? -'i^ior r-'in-orisci
Asnl 70*6Ministry cr Wamr .'rngBl an ard Electricily 
□atm irr gnl on Study arc Ctes gn P-n^pc1
Vnlurnr VII Pina? Oner a Iw, Maintenance and .Safely Manual Pam il Irigji on and pram age System
V-groove aang the face o! the cracks before filling with scaling compound Miner cracks on the lining may De sealed by dumping powdered clay upstream of the cracks
^he l rung should be protected from the ingress of rain water behind the lining The free edge should be welt tucked ?nto the canal bank. Turfing of the slope above the lining level would greatly help in preventing scours and gully formation
Su table measure should be taken io bnng the canal to carry its authorized discharge when it is noticed that the discharging capac.ty is reduced. It should be done by maintaining the lined surface of the canal to its original shape and slooes.
7   103.   Damages,   remedial   measures   &   maintenance   of   cross   drainage structures
a) Damages to cross drainage works
Damages to cross drainage works are manifested by the following
•    S.lting and/or be rm;ng / choking in the drainage charnel,
•    Seepage, piping, scour and/or undermining.
■   Sloughing and/or cawng;
•    Uplift and/or upheaval,
•    Structural cracks,
•    Out flanking/over-to ppi ng,
■   Sinking and/or differential sellemcnts.
•    Growth of shrubs and other vegetation in the drainage barrels
■   Meandering of u/s reach and/oi change in the drairage course in the vicmity of cross
•    drainage work,
•    Choking of pressure relief valves4ilters,
•    Bearings not functioning properly,
•    Malfunctioning □* gates; and
•    Leakage through jorits, seals and water stoos
o) Remedial measures fo< the damage to cross drainage works
Remedial measures for the a am ages to c/oss drainage works are mentioned belcw
• Silting is a common feature observed m cross drainage works Silting takes place r the bed of the approach channel, orainage events and exit channel, resulting in reduction of effective area fur passage of water causing headirg up of wafer to levels higher  than  designed,  thereby  over-topping  the  cross  drainage  works  ano  canal banks A meandering drainage course is likely to deposit silt in a disproportionate manner in the drainage course Regarding de-sihirg of the bed and training of the
WoterWfl'ks   Design   a"- Super* *, -q Erterrp sc
52
Ar 2TSMinify of Wrtir Irrigation and Etectftily 
Vg ve- V"i -Final Operat-on, Malnfcnanca and Safety Manual
abus r>n>i! pn Siudy a-d Oes-gr Project ________  __________ Ptfrt H- Irrigation and Dra^qr System
drainage course can Pe considered If choking due to debris has taken place, this 
shall be immediately cleared.
■ Undermining of the structures  by  deep scours  durirg flood is  one of the serious 
□angers  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 p-t 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 blocks/stone apron provided in front of upstream and downstream culo fs as a regular maintenance measure.
iii     Need to provide deeper cutoff or increasing length of existing fioor may have to be examined and adequate remedial- measures taken in case Diping has set in as evidenced by cavities detected under floors; and
f
t
iv    Ta prevent such cavities in the floor, provision of compacted filler material to form  sub  grade  shall  be  made  Where  cavities  have  been  noticed,  the  floor shal!  be  removed  above  it,  the  cavities  filled  with  compacted  'filter  material and the floor repaired m addition Io lakmg up the measures mentiored in item (iii) above
•     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  Danks  may  obstruct  lhe  water  passage,  causing  heading  up  of  water  with consequential   over-lDpping   of   structure   or   undermining   and   scour   downstream Adequate, timely steps shall be taken after tnspectron to prevent sloughing or caving of banks, if anticipated
•     The barrel portion, the exit and entry points shall be rendered free of shrubs and vegetation to avoid obstruction to the drain flow
■   A meandering water course n the vicmrly of the cross drainage structure may result
in embayment or endanger the downstream protection work. Suitable training works 
may have to be provided at such locations.
c) Maintenance of Cross Drainage Works
Before Rainy season
he approach and exit channels in the vicinity of cross drainage work shall be
cleared of silt debris stumps branches of trees etc. before the rainy season
•     Any cracks and holes n upstream and downstream Poors of the cross drainage work shall be duly repaired
- It shall be ensured that water seals or asphalt joints are intact. Leakage if any shat! be corrected by use of proper filler material.
•      Concrete  blocks  or  stone  apron  provided  n  front  of  uostream  and  downstream cutoffs may be replenished as a regular maintenance measure
Water Wo ks Drs gr and
r
53
Suqc'vis nr Fntc'prise
Apri' 7016Minis’jy gf .rrrniihor and Electricity patusjrngattfjn Study jnd Design Pryec:
During Rainy Season
Volume- VII -Fvtaf Ooenlion, Mamie nance a-nd Safety Manua,' Parrt II- Irrigaton and Orainag** Sy item
■   During rainy season, a vigilant watch is required in major cross drainage work Adequate gauge readings must be recorded during rainy season Return flow
and eddies near be cross drainage works need be watched.
■   All fallen out or disturbed pitching mat be made good.
Post Rainy season
•     The lop levels of structure should be recorded for getting information if there are any settlements
•    If any gully or any caving is seen in canal barks or al the junction it should be treated with suitable selected so;is.
•     If hair cracks are noticed in the reinforced concrete s?ab or beams, they shaft be carefully pressure-grouted with neat cement grout after thorough investigation of the cause  If  wider  cracks  arc  noticed  they  shall  be  grouted  with  mortar  grout  of  rich mix   of   cement   and   sand.   If   peeling   off   of   concrete   is   noticed,   exposing reinforcement, the damage may be repaired by Grunting or shotcreting with B.R.G. fabric,  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.
•     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 do not fade out for a long time. The gauges shall be checked for correctness.
•     Any damage to the bed and sides is to be recorded on the appropriate register and arrangements made to prepare it
7.10.4. Regulations
No leakage should be permitted through the heads of canals that have been closed, as a little water dnbbling down a canal promotes the grow’-h of grass and weeds rn the bed. When a canal Is first ooered after clearances a low supply should be run, for a few hours and the gauge then gradually raise according to the requirements.
I he gates at the cross regulators should be lowered only after the parent channel has been
run for some time The lowering of gates should be to the extent necessary to create the designed reservoir level. The downstream of lhe parent charnel should not be kepi cry with
full reservo?r level upstream of the regulator unless conditions require lhe same and lhe structure is destgned for it.
For regulating supplies  mto the distributaries  the discharge through each bay  should be more or less equal when number of bays is more than one Suitabte silt control measure should be introduced where excessive silt is tikety to be drawn by distributors.
Standing regulation orders for all important main canals and branches and critical works there on should be framed arid observed to ensure safety of works and proper utilization of water These regulation orders  should be action oriented specifying the duties  of various categories of staff connected with the regulation work and should be m possession of ak the concerned staff looking after the maintenance.
Waterworks Destgr arc Suoc*v sz  Ertapnse
_
Au",Pc 1EWnislry qI Waler. Irrigation and Siecrrioty 
Volume-VII -Final Operation Maintenance and Safety Manta.
Dabus kr ga; on Study md Design Reject ________________ _________ _______ PaM IP krigaticn and Ora:rage System
No regulator should tie planked jp higher [han is necessary for regulation, ar kept planked up after the necessity no longer exists
The staff n charge of a canal regulator or distnoutors  head should always  have written instructions  aboul the gauges  to be run the maximum and minimum permissible being clearfy stated therein A line marking the full suoply level should be painted on the upstream face of every structure If there is no structure <n a considerabl y long reach, full supply level should bo marked on the profile walls specially constructed for this purpose such that it is conveniently visibfe from the inspection bank
7.10,5. Outlets
All outlets should be regularly checked and set right if tound defective., in accordance with the detailed instructions issued by the department Outlet pipes should not be left lying aboul the canal They  should be carried to the nearest inspection house as  soon as  change in outlet has taken place and pipes arc found surplus They should bestacked neatly
Water courses  should have cu'verts/siphons  wherever needed and should be properly maintained to avoia wastage of water Register should be maintained and head of water ( h ) of each outlet i e the difference Detween the waler level in the canal and the censer line of the outlet at its exit ena. 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 the outlets  should be so fixed that these draw their proportionate discharge/silt when compared to the suppiy rn the parent channel
7 11 Maintenance of Hydro-Mechanical Installations
All machinery at the works should be kept clean, tidy and in p oper working order and care
r
should be taken Io ensure that rt is properly handled in conformity with the manufactures'
nstr actions.
7.11,1.  Protection and maintenance works of gates
•     AU lift gates shoulo be operated at suitable Intervals to free (he mechanism and wash out extraneous material.
■ In ow supplies, rising of gates by 15Dmm for a few minutes suffice If the gates have nol oeen moved for a long time, they should nut be raised all at once rather should be lifted by about 30mm and should be left at that position for about 1 a to 15 minutes Illi  silt  deposited  gets  softened  and  waler  begins  to  ooze  out  This  is  essentia1-  to avoid heavy strain on the machinery.
•     Speed rtf operation of gales should De I miled to the max’mum speed indicated by the manufacturer
•    All cavities and angles in the gates/sh utters should be kept clear of debris, th fl wo nd moss and silt accumulations
•     All drainage notes in lhe wens of horizontal structural members should be kept open and no water allowed remaining entrapped.
Wd'rr   Wg*ks  Design  and S^D'_ v vc~ E^cra'isc
55
,r
Ar,i 70*6Ministry ol W3ler Irrigalian and Electricity Dabus Pffigat'or- Study and Design Prpject
Volume VII -Final Opera lion. Maintenance and Safely Manual ______ Pafri II- Irrigation and Drainage System
•     Green slams should not be allowed to form on the steel members at the back of the gates/s butters
•     The gates and counter balanced boxes should hang perfectly level and in plumb
This should be checked occasionally and adjustment made as needed In case of shutters, the chains/anchors holding them should be kept free from rust
•     No painting is required for machined surfaces and surfaces of slamless steel, brass ar bronze These surfaces shall be protected by a coating or gasoline soluble rust preventive non-corrosive compound
•     Upstream face of the plate which comes in contact with waler should orefcrably be oainled 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  chlorinated  rubber  based  paint  or  epoxy  coal  tar  paint  (cold application) The upstream face may also be painted with any of these paints These paints may be substituted with decaf alive paint *or better appearance
■ Weld spatter or other surface irregularity shall be removed by any suitable means
•     Oil, grease or cfirl, if any. shall be removed from the surface by the use of solvents, that is, clean mineral spirits, naphta or while gasoline’
•      Any  dust  or  grit  remaining  from  this  cleaning  operation  should  be  completely removed from the surface by brushing or with dry air. and
•    Fainting shall be immediately commenced after cleaning in accordance.
Gale Grooves
Grooves and particularly their machined faces should be kepi clean and lubricated well and all sticky deposits should be scraped off before application of lubricant.
Seals
Efficiency of rubber seais should be tested initially after construction and al time of closures 
f
or isolation of different portions  or repairs. The horizontal and verticality of the seal set and wall plates shall be checked with spint level and seal faces of the rubber seal should be tested to press uniformly both by light test and by use of paper strip inserts. Seals of the gate should be checked for wear and tear and deterioration These should be adjusted/ replaced 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 wlh the passage of lime while in stores.
Staunching Pipes
Staunching  pipes,  where  provided,  shoud  oe  checked  for  their  sealing  efficiency  and necessary repai^replacements earned out
Steel Wire Ropes
All steel wire ropes must be cleaned to remove al! dust accumulation and Rubricated with suitable greases al feast once a year The portion of slee wire rope which is submerged in
Was? Warks Design ana Supervision Frierprise
Ac.nl, 70 ’fiMinistry ofWa:e-' legation and EledriOty 
rkilmr. rr
S^ciy and Devgn Project
Vulume- VII -F ra Operation, Main ten ano: and Safety Manual _____ Parrl II- Irr^ation and Drainage Stsltr-n
water  should  be  lubricated  frequency.  oreferab’y  thrice  a  year,  rhe  clamps  shall  also  be inspected
Roller Trains and Fixed Rollers
The *olter trains should be examined at least once a year Partially jammed rollers should be cleaned, freed and greased but totally jammed rollers should be replaced. The balls o< roller
guard should be checked and tightened The slrding/hxed rovers should be ext acled at
r
the
time of closure (unless  necessitated otherwise due to some defects  which may  neeu immediate repairs), and cleaned and greased properly Worn out pins should be replaced aro suitably held against rotation by filling the empty space between the pin and the side plates through welding or by other approved means. Spare rollers should be kept in stores for ready replacement.
Winches/Hoist
All winches and lifting drums should be examined at teasl once a year to see if all the gears and axles are clean ano properly lubricated A l grease-fed bearings 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 lull* of lubricants and covers tightened periodically Id 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
•he working of ary 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 operator should be correctly marked and the limits of operation indicated.
Issue of Certificate
The cngrnccr-in charge should test a i lift gated, and chain and clips of falling shutters and suomit a certificate to the competent authority (as laid down in regulation orders) before ’he advent of the famy season that all gates/fallmg shutters are m good operation condition,
7.12.     Maintenance of Drainage Systems
7.12.1. Structures on drains
i. Drain drops
Low masonry  drops  will oe provided along the drams  Drops  will oc  kept small so that earthworks in the drams a'e minimized the structures for all chains are io be constructed from stone masonry Pitching will be provioed upstream and downstream o* the masonry structures
Waterworks Design ann
SUDC’V'S'C" Fnle'Or St!
Aor.i ?315of Water, Irr^aUGfl and Electricity Dabus Irrigation Sludy and Design Project
ii- Drain outlets/Outfalls
Volume- VII -F-ina' □□eraticn Maintenance Safety Manual
______________ _  ParrUh Irrigation arg D-ainngc System
The collector drains discharges into an existing gully the gully bed will be protected with low checks  constructed from gabions  or masonry to ensure that the gully is not deepened or extended as a result of the focused drainage created by the irrigation and drainage system.
Pitching will be provided at the end of drams  whenever they  discharge into the pasture lands This will be designed Io dissipate the flow over a wide area, thus reducing its erosive capacity. In addition we will make provision for additional bed protection in the form of checks  and additional pitching as  scour protection^ to be directed during the course of construction, if we Fnd that the drains are causing localized erosion at their oullcts
To keep the sustainability of drainage systems the following precaution should be taken
■   The inspection bank should oe maintained m good condition
■    Silt cleared from the bed of a dram should be used to till up holes and ruls on lhe inspection palh/raise the canal banks/servicc roads This silt should not be thrown up m drains.
•      Trees  should  not  be  allowed  to  grow  do  the  inner  slopes  of  drains.  The  dead
branches  and  rubbish  that  may  have  accumulated
in  the  drains  should  be  cleared
before the rain breaks.
•
Hunds  should  not  be  permitted  in drains and sho
uld  be removed if  found existing
before rain breaks
•
Discharge of drams should be observed each year
at suitable points and recorded in
a register.
7.12.2
Drains Maintenance
All lhe natural drains are below ground level and can accommodate lhe discharge that come from the catchment and the field For easy flow of drainage waler
•    Removal of grasses debris etc should be done oer’odicalty.
•     Maintaining lhe x-section (side slopes and banks) of drains after irrigation and rainy seasons and
•    Siltation snould be monitored and removed before the drainage season
7.13 Sources of Materials for Repair
lhe construction materials of irrigation structures are soil, masonry or stone, steel concrete concrete pipe, wood etc Canals are constructed by concrete p pc, soil cut or fill, or masonry
lhe major problems  associated with eaith canals  & d rains  are erosion, breaching and station Properly  designed lined canals  will avoid problem of sillation, erosion and breaching, loo But depending up on the length of their service i.e design period they need prgger maintenance. Suitable earth for repairs may be obtained from the following sources
• Material obtained from internal clearances shall be utilized
Water Works Des gn ana Supervision En:ete* *-,e
5y
Anri 2QlfiMinistry Water, legation and Electrlcly 
Volume- vn -Fink Operation, Va ntena^ce and Saitety Manual
_Dabus Irrigation Slutty and Design P'ojecl _____________________  Pam II- Irrigation and Drainage System
■   By Removal of irregular Hies - High hanks can be lowered and bumps nr projections on lop or sides cut down to fill in the hollows.
•    From Spoil Banks
■   From Prominent Mounds m the fields Near the Site
•    F rom Beds of Drains Nea the site
r
Tne fallowing precautions shall be observed tn taking earth from out-side borrow pits:
•    No borrow pits snail be dug within 6m from the toe of banks or driving road or ramps of bridges
■   Earth shall not be lanen from the toe of banks, as the natural rounding of the corner should not be disturbed
7.14. Personnel Need for Maintenance
Three types ef personnel are needed forR/M activities
A Self-help - They are beneficiaries themselves They do net need any type of technical or financial help
B. Local support- Help of crafts man like mason, p:umber or a mechanic is needed for carrying out repair works and it may be met out of the financial resources uf the WUA.
C. Specialized support - They are mostly Engineers or Environmentalist needed for regular yearly inspection after the rainy season on the initiative of the ‘monitoring Evaluation Cell"
Water Wl^s Design and Supervis 7" tnteT-se
59
Ar . ZDifiMini&try of Wate , Imgalic" And El«dndty Daaus Irrigation Studv uno Desgn Project
Volume- VII -F nal Operation, Ma:nlenarce and Sa'ely Manual Parrt. II- Irngallon a*d Drainage System
8.       PROJECT ORGANIZATION ANO MANAGEMENT
01. General
Dabus irrigation project Operation and maintenance organization structure is proposed to bo organized under the Regional Agriculture Bureau Hence, upon the completion of the construction phase, the M0W1E will transfer the Irrigation project site office with its facilities and manpower to the Benshangul Gum/ Agriculture Bureau (BGAB) Since the Dabus irrigation project is a large scaie irrigation project which needs an autonomous Organization and management to lead and control its day to day activities at the site. Hence, it will be a necessa-y situation for BGAB to establish a scheme that will be functioning under tls umbreNa
Therefore in order Id promote a closest supervisory  and administrative role for the envisaged project, it would be an imperative situation far BGAB to establish an autonomous organization^ unit under its chain of command at the site. In view of that an Enterprise has to be set up at the site that wiT be fiJFy responsible for proper planning, implementation and control of the envisaged project.
The proposed organizational arrangements and irrigation management system for Daous Irrigation scheme operation and maintenance are describe under section 8 2. 8.3 & 6.4 below
8.2     Establishment of Dabus Irrigation Development Enterprise
Dabus Irrigation Development Enterprise (DIDE) shall be established at the site under BGAB The Enterprise shall be funded and staffed by the Regional State of Benshangul Gumz to undertake the operation and maintenance activrties of the scheme until BGAB transfer r? to the end users.
8.3     Objective of Dabus Irrigation Development Enterprise
The main objective of DIDE is to ensure the avaitaoilily of equitable and sustainable water distribution among different canal system within die scheme, to maintain the safely of the infrastructure of the main and secondary caral system and to supervise periodically the over functionality of the tertiary and flexi flume system of the scheme. In addition to organize water users associations as well as to assist them ti training and agricultural input supples, marketing and extension services
8.4       Proposed  Organizational  Structure  for  Dabus  Irrigation  Development Enterprise
The designing of an appropriate structure contributes a lot for the accomnli organizational objeetves in an effective and efficient manner. Since
Development Enterprise (DIDE) is responsible for me Operation and th;s large scale irrigation scheme, the structure is proposed based c and the type c‘ irrigation system used as well as the existing ponies,
. of
WaterWtns   Design   arc Slor^iS f-nlerpr'KE’
50Ministry of Waler i rugate ard Beanoty 
Volume-VII -Final Oparaliorr Mairtenartce arw Safety Manual
Dabus Irnggtior' Study and Des»gn Pujec?                 ____ ____________ il Imgatian and Drainage System
and practice of organizing similar schemes Structure. |ob descriot-on and staffing plan of the proposed development enterprise is described in figure 8 1 below.-
Figure 0.1: Dabus Irrigation Development Enterprise Organization Structure
8.5.     Responsibilities of Dabus Irrigation Development Enterprise
The Enterprise will be responsible for operation and maintenance of the irrigation scheme, organizing the community, for capacity  building, providing assistance and advice on agricultural and irrigation system management; In particular it will perform the following
•    Plan, organize and control the Operation and maintenance of the main and secondary canal infrastructures of the irrigation scheme,
•    Ensures application of equitable waler distribution for the whole scheme
•    Manage maintenances of diversion werr mam canal, mam road and other related activities;
•    Provides technical supports and advices to the Water Users Associations (WUA) in the command area;
•    Organizes trainings and experience sharing programs.
•    Enhances the confidence of the local people in the scheme management through various awareness creation programs,
iiV.dei Woiks Design and Supurviwr Er-crcnse
Aarit, 2016Ministry □( Writer. Irrigation and FlecLncdv 
Volume- VI i -Final Operation, Maintenance and Safety Manun:
□abus Irrigation Study and Design Project ____________ _______________ Far-ill- ftfrgalion and Drainage System
•    Provides on-the-job training to enhance the capacity of locals lo operate and maintain the scheme,
•    Proposes sustainable and appropriate water charges, and Collects waler usage charges;
•    Bui'ds up the local community's capacity for future management, operation and maintenance of the scheme through continuous on |ob training,
•    Conducts market surveys and advise farmers an marketing options and networking's.
•    Provides various Agricultural extension service tn the farmers
•    Performs other related activities as directed by Benshangul Gunv Agriculture Bureau
8.6 Responsibilities of Water Users
•    Farmers have lo follow the designed cropping pattern and operation as revealed on the ran report.
•    During operation maximum effort shall be aoplied to lessen water losses;
■ Farmers participate In labor and financial requirements m the call for operation and maintenance;
•    Farmers shall follow the time schedule of irrigation as presented in this manual if there could be any problem can be resolved by the WUA/ irrigation agency
8,7, Responsibility of Operation Department
The Operation Deoartmert will perform the followirg major activities
•    P ans and Leads lhe Maintenance activities of the irrigation system,
•    Assess the water requirements and supply of the irrigable area.
•    Controls the Conveyance and distribution of water,
•    Plans and decides the amount scarce waler to be Distributed during water stress periods;
•    Application and drainage of excess water from fields and eventual reuse or removal;
•    Derform$ of other related functions as directed by the manager.
8 8 Responsibility of Maintenance Department
T he maintenance Department will perform the following major activities
•     nians and leads the Cleaning and repairing of canals and drains,
•    leads and controls the repair ng of structures and canal linings and clean ng and lubricating gates.
•    Plans, Organizes and leads the activities of the Enterprise workshop;
•    Plans and follow-up the Clearing and greasing of gates keep rg structures clear of floating debris and filling m small rain gal cys on caral and dram embankments
Wale-* Warks Design ana Sjpei-y si on Euler 3’ise
62
Aqr|: 2016M.:nislry of Water                   arc Efectncty pah us irr. gallon Study and Os gn n-oject
Volume Vll-F nal Operation. Maintenance and Safely Manual Parrt H- Irrigation and Drainage System
•    Leads and controls the repairs of structures and grading embankments to improve access roads;
•    examines of canals drains and structures and reports of any problems.
•    inspects the Day 1o-day of farm channel and water courses
•    Ensures that the proper Maintenance of the Maintenance department own machinery and equipment as we'l as vehicles of the enterprise,
•    Performs of other related functions as directed by the manager
8.9.     Responsibility of Water Users Associations
The Water Users Associations will perform the following major activities
•    Prepare plan for allocation of available rngaton water.
•    Delivers irrigation water to individual farmers in accordance with the approved plan
for water allocation;
•    Regjlates supply of water in accordance with the approved olan for water
allocation,
•    Undertakes the maintenance of the canal system including related structures;
•    Undertakes routine /annual andtor special repairs.
•    Carnes out the operation of the canal system to supply irrigation water;
■   Ensures equitable distribution of irrigation water amongst the farmers:
•    Conducts assessment and collection of water charges from the beneficiaries;
•    prepares annual budget for the financial year and maintain proper account of the
same,
•    Ensures that regular audit of account is done
•    Prepares special plan for special reoairs/dcvelopment /mo derm/at ion and undertake the same;
•    Wakes Fund arrangements for special repair and/or modernization.
■   Resolves conflicts among individual farmers or different committees.
•    Performs of other related functions as directed by the General Assembly.
8.10.   Infrastructure Management
[he infrastructure includes the headwork, the main conveyance, the night storage Feservoir. various  structures, distributor canals, flexi flume, outlets  and drainage system The management aspect considers procedures and methods for checking and eva uabng the desired Junes.on of the carals and structures including farm outlets during operation
8.11 Management of maintenance activities
The objectives of maintenance management in an rogation scheme are:
Wr   Wcrk5   Oesig.n   A-rt Suprrv s :r Entero isc
f
Ann', 2CJEM  miry  or  Waler  legation  anti  Flectn&ty Dabus Vngnliqr: Stuay and Design Project
Volume-Vir-Frj!    Operator,    Ma-rtenjnce    arc    Safely    Manu.1-
_____
____ Parc il-1 mgaI ion and_Drainagr? Sy5tc*rn
•     To keep the scheme in good operating condition so that it will provide uninterrupted service;
•    To extend the useful life of the scheme,
•    To achieve the above 3t the lowest possible cost
8.12.  Management Task
For the proper operation and maintenance of the management body of WUA has to perform certain management tasks. These include
f
•    The Leaders of lhe WUA wilt take care of the waler right o the project
•    A good relation will be maintained with all other projects or groups of waler user,
•    The Leaders will appoint the day of the beginning and end of new irrigation season;
•     The Leaders will take care of the conveyance and distribution of water to (he farm units, in accordance with agreed rate of supply and delivery periods, described in the project study
•     The Leaders will organize lhe maintenance works, acquired lhe required materials, and will fix the annual contribution for these works
•      DeFniton  of  works  frequencies  of  maintenance.  tasks  of  water  users  will  be established.
•    Contracts with local skilled and unskilled labor wilt be concluded;
•    The Leaders will collect water charges (if decided) imposed by the irrigation Agency;
•     In all disputes about the system operation ard maintenance and m other external problems the WMC of the WUA wilf take lhe final decision and
•    The I eaders. if the farmer fails to pay their annual contribution, will fix penalties
Wa’e* Warks Design grig Suoen# icn EnteronsB
A- ?016Ministry al Zfat&r imgaiian and Eksctnoty 
□isols frngallon S’.wdy arjJ Design Rrojejzt
Voiurtr VJi —Final Operation, Maintenance and Safely Manual p arrx H frngaticn and Drainage Syatern
9.       EQUIPMENT REQUIRED FOR MAINTENANCE AND OPERATION
9.1.    General
The maintenance of canals and drams in the Dabus Irrigation Projec’ is simole affair as the can a is will rem am closed for some periods and hence maintenance can be done during closure periods and as the canals are small sized, the maintenance will oe done mostly manually However some machinery will be kept for some emergency
9.2.     Machinery for Maintenance Embankment and Side Slopes
The side slopes of the embankment of canals and drams have to be kept smooth to prcvnnl erosion and Io allow mechanized weed control The best choice for this operation is (he motor grader and consists of a hydraulically operated mould board of 3 m width.
This blade will level and grade the side slopes of canals, dykes, roads, ditches, etc with (he grader traveling alongside. The soil or silt is Drought on the bank or road and is moved further with the regular blade in a following pass
The grader and sloper can also be used (or debiting small canals like field drains, provided there is path alongside Under these conditions, this motor grader can obtain high outputs After experience gained, more motor graders can be procured if they prove to be useful n comparison of manual labor.
9.3.     Machinery Tor Control of Grasses and Weeds
Control of grasses  and weeds  can on the embankment and slopes  is  necessary  to discourage development of pests, shrubs and trees which could damage the banks and to encourage soil binding grasses
Mowing can be dene by a (lari mower al the end of a hydraulically operated boom This can
be a speoa. attachment Io an agricultural tractor With such a tractor the maximum reach would be aooul 5 m ard working speed about 4 km per hour resulting rn a net production of
2 km
9.4.    Machinery for Maintenance of Flood Protection Embankments and River Course
Dykes or embankments reouire close supervision and routine maintenance to strengthen wea< reaches each year Major maintenance is requrred at least onoe in 5 years to raise and strengthen eroded sections. Removal of the obstructions  in the river course nas  to be performed as  and when required Normally  it Is  not required These activities  can be oerformed by a Bull Dozer with scraper box and wheel loader
Wait* Wcrks Des gn q*iil Supers on Frle~' se
55
Anril ?o*5Ministry of Water. irrigation 3”<} Electricity 
Dabus Irrigation Stucy ara Design °rc ec!
9.5 Machinery and Equipment required
Vo.urre- V i -F ml Operation, Ma:rtenance and Safety V-anuni
Pam ll- Irrigation und Drainage System
Table 9 1 Required Machinery and Equipment of the project
Descriptions of item/ Equipment
Required
Number
Methods of
Fulfillment
Pickup vencle
4
Renta’/Purchase
Motor Cycle For main Canal Operators
6
Purchase
Motor cycle for Reservoir Operators
6
Purchase
Motor cycle for Gate/Canal Operators
6
Purchase
Excavator
1
Rental Purchase
Dozer
1
Rental/Purchase
Motor Grader
1
Rental/Purchase
Heavy T ruck
1
RentalfRurchase
Roller
1
Renta tfPurch as e
Low Bed
1
Rertal/Purchase
Source Volume IV - Part VII Organization and Management
Study F nal Report
'Adler Works Design
66
Sucres i-cn Fnlerc sc
x
Ayn 2016Min s!ry of Writer, Irr q a I ion ana £!ed o1y 
r
Dabus Irrigation Study ana Design PrQ.-ed
Volume’V -Final Operation Ma^enance nnd Safety Mrt.'iiJfll ________ Pant II- VngaUon and Dra ~age Syalerr^
10,     MAN POWER REQUIRED FOR OPERATION AND MAINTENANCE
10.1 General
The number of manpower required and the skill needed depend on lhe size of the scheme, the method of water distribution and the number and size of the farms  The proposed manpower for Dabus  irrigation project is  based on the above operational requirements during the actual operation and maintenance
Irrigation operation staffs commonly required in largp irrigation projects arc Gate Operators, Water Guards, Irrigation Assistants  (Super-intendants), and Irrigation Engineers  As  large scale irrigation farms are new to Ethiopia, there is no domestic expenence Id be used as a base for estimating the manoower requirement According to literature 1. however, each Water Guard can look after 100 to 150 ha or more, depending on the type of system and the size and number of farms An Irrigation Assistant can supervise four or more Water Guards covering about 500 ha An rrrigation Engineer, on the other hand, could be rsponsible for up to 2000 to 7500 ha or more
Depending on the above assumptions, the initial manpower requirement for the operation and maintenance activities of the project arc provided n table 10.1 .below:
Tabic 10.1 Manpower Requirement of Operation and Maintenance work
Location /job title
IMn
Pra
Requirements 
Education
„
.
Experience
General Manager
1
SSc -n irrigation/civil Eng
10 years
Operabor Department
Depadmcri Head
1
Bsc IrngatiorVCivii Eng
R years
Irrigation Engineer
3
Bsc Irrigallon/Civii Eng
6 years
irrigation Assistant
12
Diploma in irrigation
4 years
Water Guard
30
Graded ana training
0 years
Gale Operator
6
Grade 6 and training
0 years
Reserve Weir Operator
6
Grade 6 and training
6 years
Main Canal Operator
6
i Grade 6 and training
4 years
Maintenance Department
DeparImen! head
1
BSc m Mechanical Eng
8 years
Civil Engineer
1
Bsc in Civil Eng
6 years
Mechanical Engineer
1
BSc in Mechanical Eng
4 years
Maintenance Supervisor
2
Diploma in Irrigation Eng
6 years
Excavator Operator
2
Trained with license
4 years
Dozer Operator
2
Trained with license
4 years
Motor Grader Operator
2
Trained with license
4 years
Roller Operator
_2
Trained with license
4 years
I ow bed operator
1
certificate and license
4 yea<s
Small Crane Operator
?.
T rained with icense
4 years
Heavy Truck Driver
2
8th complete with license
4 years
Pick Up Driver
2
8th complete with license
4 years
Senior Mechanic
1
Diploma in Auto Mechanics
6 years
Mechanic
3
Diploma in Auto Mechan.cs
2 years
Senior Electrician
1
Diploma in Electricity
6 years
Electrician
2
Diploma in Electricity
2 years
Senior Welder
1
Diploma in Welding
4 years
Weiner
2
Diploma in Welding
2 years
Carpenter
1
Diploma in waodwn K
r
4 years
Source VcVfre V- Pin VII Organizabon and Management Study F-nal Report
Wiif Works Design And
67
A aril. 70*6V nisiry □' Water. Irrigation and Electricity 
Dabu* Irrigation Study and Design Project
Volume-VII - Final Opt'ration, Maintenance and Safely Manual ______  Pa<rt II- Irrigation and Drainage System
10 2. Job Description of Various Staff Required for Operation & Maintenance
10.2.1,  Project Manager
Project Manager will be responsible far overall Administration. Planning, Maintenance of Structures, Operation of various  structures  and Waler Management and Agricultural Extension
10,2.2.   Maintenance Engineer, Irrigation/ Civil and His Teams
•    Plan, organize and supervise the required maintenance activities periodically.
■ P!an organize and supervise the proper state of functioning and maintenance of all
r
Equipment and machinery of the PMIJ;
•     Administer all activities in maintenance and report lo (he Central Administration Unit, water management unit through the Project Manager anything relevant in lerms of requirement   of   laborers',   machinery   materials   and   the   like,   according   to   the eslablished procedures of the EMU,
•     Estimate requirement of labor etc. and material in advance of Lhe rainy season for proper maintenance of all the Canal and Drainage Sydem and Dykes;
10.2,3.   Mechanical Engineer
Duties of Mechan cai engineer are detailed here under
•     Inspect Maintenance of all gates of Outlet, under sluices, head Regulators, all canal structures etc are in good order,
•    Carry out Inspection of all gates regularly;
•    Maintenance of workshop and ts equipment;
•    Maintenance of Vehicles;
•    Maintenance of all Machines
10-2.4, Mechanical Foreman
Duties of Mechanical Forman are
•    Maintenance at Gates in good order
•    Inspector of all gales regularly
10.2.5.  Water Management Engineer
lhe Water Management Engineer is responsible for (he operation of the whole irrigation system. In particular ha/she will perform the following
•    Supervising irrigahon assistants
■    Preparing irrigation plans
■   Working close y with agricultural staff to clan the suoply and demand for water,
Wa'er Works Oesig” a'S Su&crvs'ar
■53
April, Z316Minisl'y n? Woln*. Irrigator and EtectrieHy Dab'.s r gallon Study and Design Project
r
Volume- VII - Fina Opera I-do. Maintenance and Safety Manual Pari It- Irrigation and Drainage System
■   Reporting all maintenance needs to the maintenance dcparfrnent;
■   Reporting to the general manger on the irrigation system and its ruture needs.
10.2.6.   Monitoring Technicians on Groundwater
•     Acquaint him with the location and characteristics of each observation wen in the project area,
•    Compile, analyze and evaluate the field data:
•     Report to the Water Management Engineer any abnormal observation in connection with the fluctuation or water evcJs or salts in water samples of each wolf.
•      Identify  water  logging  or  drainage  problems  existing  or  that  may  exist  within  the developed area;
•    Develop Ground Level contours and determine the direction of water movement;
•     Plot ground water electr cal conductivity contours Maintain and be responsible far the instruments issued to him
10.2.7.   Irrigation Assistants
The task of Irrigation Assistants will be to coordinate the work of water Guards whren
include:
■    Collecting information from water guard on water requirements maintenance needs and land preparation and passing this to the frngaLion Engineer
•     Passing instructions on water allocations from the Irrigation Engineer to the water Guards.
■   Organizing training courses for Water Gua ds, Gate Operators and irrigators.
r
10.2.8.   Gate Operators of Head works
The gate operators of head works operate the gates of the head works and assist rn maintenance of the head works They will:
•    Work m 8 hours shifts to cover 24 hours per day, the shifts will be from 6.00 AM to 2 00 PM.. 2.00 PM to 10.00 PM and 10.00PM to 6 00 AM;
•    Not leave the Head works unattended during their B hr shift.
•     Record accurately on the forms provided, the upstream and downstream river levels 
and  gate  openings  every  hour  with  specia'  attention  paid  to  the
record  peak  river
levels during the floods;
•
Learn  thoroughly  how  to  adjust  the  heao  regulator  gates  for  a
required  constant
discharge in relation to the fluctuations in to ever levels,
■ Record all changes/ adjustments to gate openings,
•    Report regularly all recordings to the Dam Superintendent,
•    Be attentive and report Io higher ups any scouring of the river bank near the darn,
•    Ensure that no unauthorized personnel amoer with the gales;
Water Wrvks Design 4re Si.uc'vis'on FMerer se
Agni, 2U16Ministry of Witter 'rr gallon and EiBElridty 
Vc* jrrr■ Vn'- -Fifisl O&crafia^ Maintenance snd Safety Manila’
DabusJrrigatlan Study and DM<gr Protest __________________________  P»n ii- irrigation and Orriinage System
•    Keeo all records/torms. Registers and Graphs ana tables, stage discharge curves in Draper order,
•    Be attentive to the security of gates operating equipment etc and rechargeable
torches in their custody;
•    Report any damage to the gates to the higher ups
10.2.9.    Gate Operators for Head Regulator
•    Work in 8 hour shift lo cover 24 hr per day. The shifts wilt be from 6 00 AV to 2.00
PM... 2.00 PM to 10 00 PM and 10.00PM to 6 00 AM.
•    Not leave their place of work unattended during their 8 hr. shift:
•    Record accurately on the form orav.'ded the gauges gale openings elc;
•    Learn thoroughly how to adjust the gales;
•    Not entertain outsiders in the gale operation cabins;
•    Keep all lorms Registers and Graphs and tables, stage discharge curves in prooer
order,
•    Be attentive to the security of gates operating equipment etc. and rechargeable
torches in their custody,
•    Report any damage to the gates or scouring of Banks of canal in the near vicinity of
the Head Regulator
10.2.10.  Gate Operator for outlet
•    The gate operators of outlet operate the gates of the outlet works. They w I Work in B hours shifts to cover 24 hours oer day:
•    Nol leave the Head works unattended during their 8 hour shift.
•     Record accurately on the form provided, the upstream and downstream river levels and  gate openings every  hour  with  special  attention paid to  lhe record peak  r ver level s d uri n g the floods.
•     Learn  thoroughly  how  io  adjust  the  head  regulator  gates  for  a  required  constant discharge n relation to thE fluctuations in river levels as given oy lhe table provided
•    Record all adjustments to gate openings;
•    Report regularly all recordings !□ the Darr Superintendent
•    Be atlcnlivc and report to higher ups any scouring of lhe river bank near lhe dam,
•    Ensure that no unauthorized personnel tamper with the gates;
•     Keep all forms, Regtsters and Graohs and tables, stage discharge curves in proper order;
•      Be  attentive  to  the  security  o*  gates  operating  equipment...etc  and  rechargeable torches in their custody.
•    Reoort any damage to the gales to the higher ups
WiCe Works Design ana
r
Suterv sen ! ■i‘e. prs£!
r
Ao* I. 2C‘SMinistry of Wale* Irrigation And U^dneity 
Dasus Im^iii'or- Study arid Dcs gn Prgfect
;
Volume VII ■*-ng. Operai.an Maintenance and 5alety Ms-tja _ P.urt II Irrigation and Drainage System
10.2.11.    Other gates
Similar as above but operation shall ae as ordered by the operation and marrite nance agency,
10.2 12. Water Guards
Water Guards are the main link between the engineers who operate the system and the
; rrigators in the field Their major jobs will involve the following
•    Helping irrigators with water management problems,
•     Passing instructions Io gate Operators;
•    C ol fee ting req u esls fo r wa le r from Trig a to rs;
•    Reporting problems on land preparation and canat maintenance.
10.213. Surveyors
At least one surveying crew of rs required for monitoring the water levels as well as during maintenance and construction of canas. structures and roads
Waler Works Dusig-. and Suiiervisior. Tri ltd1 sc
71
Aflr 1.2215Ministry o'Water, 'rr gation and Etcctncty Dabus Jrngadon Study and Design Projeci 11.     COMMUNICATION SYSTEM 11 1, General
Vclurre- VII -Final Operation Maintenance and Safely Manual __  ______  _ Pant II- irf^gaban and Drainage Syslcm
Thefe should De a regular communication system so that the WUA may  contact the monitoring and evaluation cell or regional authorities, irrigation engineers  for sending orogress reports, emergency calls, consultations etc
There shou’d be a record of crafts  men masons, as  indrcaled above so that may  be contacted when necessary for attending reoarr work The communication and approach to the headwork site should be kept in proper condition, The bank width of conveyance should be maintained for uninterrupted movement of the farmers and FWI works
11 2. Relationship of Irrigation Agencies and Water Users Association
Maintenance is a routine and carefully under taken task at a regular periods of operation of an irrigation scheme Thus it mrght be very difficult to lay all the maintenance work on the beneficiaries / farmers, especially for major irrigation structures the bureau of water mineral Energy  and Bureau of Agriculture have to assist the farmers  for technical and financial support, on the other hand the farmers are responsible for (he operation and maintenance of the tertiary units and other farm facilities
The relationship between the irrigation agency  and water users  must be positive for successfulness of the operation and maintenance the irrigation The agency has to help the farmers n identifying the problems, coordinate (he farmer so that for simple works he could solve some technical problems and also for difficult works he could repon for Bureau and he can get solution
Water Wd«xs Design andMi n»s! y of Waller,
r
Irrigation and Electricity 
Volume-VH -Fins Opera: qh. Mainlenar.ee and Safety Manual
□ab us Irrigation Study a^d Design Pro<C’:i            ___  _______________ Pa rd I>- Irng alien a^d Drainage System 12.     TRAINING
12 1 Training of Farmers
The farmers of WUA. nave to acquire knowledge and skil' regarding the plan and function of differenl component of the scheme for its proper management operation and maintenance. They have to be given training and development knowledge and know-how, how best tne completed system can give optimum results by utilizing the resources and the infrastructures and the same could be consolidated with minimum Financial -nvoivement.
f he following training p-ogram shall have to be pre-planned
i. At site (raining - their involvement being right from the inception of (he scheme, by association and group discussion
ii Workshops arranging workshoos by inviting experts on different disciplines 
hi On farm training - making visits to other irrigated agriculture farms
iv. Audio or video and - the performance of O/M at different levels in a particular on - going scheme can be demonstrated
v Any other methods
w Through trainers/ trained the WUA.
The training is necessary on the following aspects.
•    Measurements of water.
•    Maintenance works,
< Ooeration/ regulation of gates.
•    Management of equitable water distribution,
•    Behavior of structures.
•    Assessment of periodic crop-water requirement,
•    Need tor terracing works on steep slopes,
•    on how, when and how much, to irrigate,
•    Water holding capacity of (he soil.
•    water logging, salinity and drainage,
•    up keep of watershed management activities
■ Communication and reporting.
•    Monitoring and evaluation
12 2 Training for Farmers Representatives
The aim of (raining for local representatives of farmers is to equ p them in the management operation, ano maintenance of irr gallon systems, proper water usage and other related matters Capacity du; ding of the local people m opera: on ana management should be given a nigti priority oecause it is one of the activities most likely enhance sustainamviy and
Waler  Worxs  Oei'gn  am Svse’visior Ertcrnrse
Ann 2316Minntry ofWa’.e- Irrigation a.nrf Electrety OabuB rrngation Study end Oes gnprojet*.
Vofunw-VII -final Otrcriilion Va>r Inna no? and Surety Manna!
__
Parr*. H - Ir
rigation ana Drainage System
od
of  training  are
visits  to  successful
effectiveness  of  irrigation  systems.  Among  the  meth
schemes, group meetings between new and well established schemes are useful ways for communities to exchange experiences and focus on gaps in their skills and knowledge
The Training methodology should focus on learning by doing Therefore, on the job training
and participation of local representatives in the operation and maintenance of the scheme before transferring the scheme to Water Users Association (WUA) is highly recommended
The training should be in the local language, appropriate for different age and gender groups and the prevailing level of literacy The training areas to be provided include, but not limited
to
•    Community management structures and their roies
•    Setting development goals and objectives
•    Constitution and bye-iaws for governing the use of irrigation systems
•    Members' rights & Obligations
•    Parbematory decision-making
•    Accountabilty of leaders
•    Planning and budgeing skills
■   LeadorshipAnanagement skills
•    Mo nito nog a nd ova I uati dh mech an is m s
•    Record keeping and accounting procedure
•    Financial management skills
•    Community conflict resolution skills and mechanisms
•    Negotiation skills, contract with private sectors. w«th suppliers of inputs buyers of
their produces
■   Procurement and marketing strategies
•    Arbitration mechanisms
12 3. Training of Trainees
A detailed syllabus with emphasis on 'raining techniques has to be developed for different levels "I he purpose of the trainings is to develop special skills to the trainees for planning agricultural operation and maintenance
There are several approaches  to organizing and conducting a ’raining program II is important to provide on-the-job training and the plans and schedules have to be formulated that each trainees undergoes appropiatc training on different subjects.
Main areas of training cover the following topics
1 Basic             a) organizational procedures b) Accounting rules
c) Irrigation and drainage
Matei              [icsiqn and Sudcv 5-Dr- Erternnsc
Apr I 7(116MH»tryafWa1er Irnga'.iofl and E'etfncity 
Volume VP -Final Operation Maintenance and Sa ret/Manual
Dabus irr,gallon SLucfy andDwgn Projcti________________ ______  ___________ Pa*rt_IMrr^on andprainage System 2  Technical a) Academic matters on all fields related agriculture
b) Practice oriented knowledge
c) Irrigation scheduling, distribution & budgetrig
d) Operalion and Maintenance
12 4 Training for Members of Water Users Associations (WUA)
The Training fcr members of WUA is required to develop proper and adequate knowledge and understanding of the foltowng aspects
•    Participatory Irrigation Management;
•    Irrigation engineering.
These are described as follows
Participatory Irrigation Management: -
The main functions of Participatory Irrigation Management (P M) are:
•    Motivating and organizing WUAs intbalry,
•    Delineating the hydraulic boundary of WUA. and holdng election for office bearers.
•    Maintenance of canal system including irrrgaton channels and structure al m cro
level:
■   Operation o! the canal system for conveying, distributing, and delivery c* irrigation
water including regulating discharges and measurement of discharge:
•    Performing office work and maintaining proper accounts and records;
■   Assessment of water taxes and collection of the same
Irrigation Engineering: As  described above the members  and officials  of WUA are required to ma.ntam and operate the canal, regulate the discharge, distribute and finally deliver the irrigation water to individual field of the farmers. Wrth this end in view they are 'eauired to have seme baslc/prelimmary krowieoge of the fallowing issues for which training is very essential
•    Maintenance and operation of canal.
f
•    Regulation and measurement o discharge,
•    Preparation of plan or water allocation and its implementation.
r
•    Resolution of disputes relating to water allocation and its distribution;
•    Methods of irrigation;
•    Water management
Waler Works Des gr
f -r.Errr st
Ae* 2016M r scry of Wafer, Irrigation aro Electricity Dabus Irrlgaliop Study and OrP-d|ec- REFERENCES
Vofunifi- VJ1 -Final Operation, Maintenance ard Safely Manual P arr M Irrigation and Drainage System
1   Arjo Dedessa Irrigation and Hydro oower project Detail Design Report Volume 11 nart II Operator and Maintenance Manual for irrigation and Drainage system. WWDSL, Addis Ababa, June 2009
r
2     F/nal  Operation  and  Maintenance  Marual  for  Tendaho  Irrigation  and  Drainage System, WWDSE, Addis Ababa, January 2012.
3     Feasibility  Study  and  Detail  Design  of  Omo  Valley  Farm  Irrigation  Project  Draft Operation   and   Maintenance   Marual   for   the   Irrigation   and   Drainage   System, WWDSE, Addis Aoaba, April, 2010
4     Operation  and  Maintenance  (O&M)  Manual  for  Surface  Irrigation  of  Welienchili (Additional)  Sugarcane  Irrigation  Project  Draft Report, WWDSE, Adds Ababa FEB, 2015.
5    Dabus Irrigation Development Feasibility Study and Detail Design Project Feasibifrly Study of Irrigation and Drainage System Draft, WWDSE. Addis Ababa, Nov, 2014
6, Dabus Irrigation Development Feasibility Study and Detail design Project Design Criteria for Irrigation and Drainage System Draft, WWDSE. Adds Ababa Dec, 2013
/ Irrigation Water Management (IWM) Training Manual 10. Irrigation Scheme
Operation and Maintenance Manual. FAO, Rome, 1996
9  Metehara  Sugar  Factory,  the  Significance  of  Flexiflume  in  Cost  Reduction  and Improving Droductivily at MSF Report, Campaign 200SJQ6
9   Bartlel toxible gated pipe company brouchure, Flexi flume complete kit exportvl .pdf
10 Dabus Irrigation Development Feasibility Study and Detail Design Project, Volume IV
- Part VII Organization and Management Study Final Report, WWDSE, Addis Ababa. June, 2014
Wait* W&^s Design arte Superv s o" ="terur^e
-/C
April, 7Q'6Ministry of Water, Irrigation and EJectncty Dabus irigaiipn SlLrjyjnd Design P- t -■
Volume- V» -F-nai Operation, Maintenance and Safety Manua.
____  ParrHI- mx^iljor and Dr am age System
ANNEXS
Water Works Design
S-2e*viai&n Ertfo* sc
77
ACf ?<116Ministry of Wafer. Irrigation arc* Efectricty 
Vafumc- V1! -Ana’ Orwrasipr. Maintenance and Safely Manual
Dabus Itrga! &n Study and Design Project____ _______ ___________ ___  Pant 11- Irrigaz.pn and Drainage systerr Annex 1 Net Command Area under Irrigation System
Net Command Area of LBMC
CANAL NAME
NIA (ha)
CANA! NAME
NIA(hal
rcoi
B4.fi
TC02
31 2
TCD3
13 26
SCl
243 05
TCO4
40.64
TC05
256
TC05
13.93
FCG6
3a <2
TC01
6 72
TC02
13 79
OCOI
5 62
QC02
B S2
□C03
6.87
SC2
75.41
QC04
5.11
QC05
5.58
□COG
5.62
TC03
□COB
7 79
4 79
QC10
6 60
TCD1
126 3B
Sixx J
jJ
TC02
96 4B
TC03
151 24
TC04
50 43
er/
3345
TC01
18.44
TC02
15 01
TC01
59 04
TG02
4B 54
DC NS
1.11
SC5
342.75
TC03
57 67
TCD4
53 94
TC05
41.90
TCDB
69.75
TC01
94 05
SCB
283.39
TC02
73 35
TC03
95.99
TC01
100 07
TC 02
183 3B
TC 03
3H 88
SCD7A
594 B 7
1
□CO?
10 02
QCC4
11 23
PG-01
QC06
18 13
SC?
1136 C-B
cede
16.51
QdO
12.74
QC12
9 58
□C1<
332
TCOS
2B.77
QC’6
B 10
QCD1
5.71
TC04
10 38
TCD7
76.39
SCB
TC01
2B.72
TCO?
54 53
SG9
H3.25
fijn 7 /
TCD1
40 53
TCO?
26 24
Wa:er Works Design and S-ccrvisior I rtferonse
76
Aon-, ?016Min Mry  oleate*' irrigaiian and Electricity 
Oabus Irrigate* Si^y and Design Project
Vo’urre- VIL 'final ClperaLon Maintenance and Safety Manua
D ard 11 -1rrrgation and Dffiinage_Sy5!cm
1
CANAL NAME
nia |tm)
CANAL NAME
NIA [bal
ran
72.53
TCO2
55 42
417 03
QCOl’OA
31.45
scio
TC04
109 67
TC03
74 16
TC06
74 6C
TC01
24 23
TCD2
91 05
TCD3
52 50
QC02
4 90
TCG4
34 93
sen
979.23
TCO5
106.00
TC06
04.06
TC07
61 76
TCOB
90 56
TCO9
207 40
TC1D
220 06
TC01
*06.04
TC02
24 W
TC03
07 45
TC04
33 94
SC12
564 ga
TC05
77.66
TC06
31 54
TC07
27 94
TCOB
20 90
I cog
36 53
TC10
71 96
sets
110 74
TC01
43.11
TCD2
67.63
SCU
17 41
TCOr
16 57
TCD2
0.84
SC15
3? It
TCD1
29 57
TC02
7 44
TC 01
7? 61
TC 07
103 67
TC-NC
697
TCO3
136 W
sets
1050 6 r
TCD4
145 IB
TC05
143 72
TC06
269 14
TCO7
96 65
TCOB
62.44
ICO9
Total_______|
31 91
6056,65
I
I
Wrilff Wfirts qr and Supervision ±rtp-p- se
79
Ar-.. 20'M r 5 rry oi Wale'. krtgahon and Etedricity Dabi -. irr.gatjon Study and Design Project Nel Command Area of RBMC
Volurrc-Vll Final Operation. Ma-nlenamtc and Safety Manual Pnrrl II- legation and Dra rage Sys Inn
-------------r
CANAL NAME I NIA^ha}
CANAL NAME
NiA (ha)
I
TC 01
56 2*
TC 02
114,52
SC1                          267 06
rc 04
60,37
re D3
13.40
TC 05
12.53
TC01
85.91
353 93
TC02
TC03
57.42
93 85
I
TC05
126 75
TC01
9? 1 a
SC3
421 33
TC02
175.77
TC03
72.55
75 83
227 77
SC4
616.55
TC04
TCD1
rco2
TC03
TC04
36 90
lao 38
171 42
SC5                86 37
TC01
TC02
57.13
29.24
I
PCCl
TC01
TCO2
TC03
TC04
40.33
185 05
22 25
51 09
I
SC6               298.72
i
SC 7
173 45
TCD1
49 4fa
TCD2
124 01
TC01
246.53
TC02
-53 67
see
719.70
i
I
l
era
267.21
TC01                          25 54
TC03
TC04
TC05
TC 01
TC 02
TC 03
TC04
TC 05
TC 06
TC (31
t03 45
102 74
113.31
IB 26
9 79
52.28
71.65
70.95
4528
25 54
Total
3239 87  I
Water  Wo'ks  Deugn  arc Supervision E^tpradse
Ar.i I. 23 i6V  -istry  of  Waler.  Irrigation  ana  Electricity 
Dabus Irrigat cn Sludy and Design Project
Annex 2
Canal Name QC-TC01-SCQ1/LBMC
FIexi numc Flexi flume Parameters and Structure Locations Data Table
Volume- VII FmaJ Operation, Maintenance gnu Safely Manual Pa.'rt J- Irrigat-on and Dra nage System
Identity of floxi flume
Design Dischar 00
Lengt h
0GL
al TC
FSL
at TC
Lowe st Point Level
FSL-
OGL
Stati c 
Head
Flummin Friction Fricll Static
g Actual Loss per on Head*
Diameter
Loss
Frictro
n Loss
Reach '
mJZ5
m              rn              rn
QC 01
01               o.oao            610
qc at
03              □ OBU           568 QOOV
05               0 080           47-1 QC-01-
1001 8
6
1002 3
4
m        "rn”           rn 20.*
100m (Shown in Mtrs Hd)
m
Total I      Number held         of
Pressure Cham be rs
Lcngl         Stat. n pe r .     c
Mm
m
2018
m
17 34
<91
17.34
Nr
m!
Head per Reac 
h
rh
1001.7      1002.0
6
9
982 18 0 49
9B2 25 0.33
1000.9      1001 8
a
2          980 25      0.86
200             0 462
2ec             C.462
280              0.462
2 624 1721
2 190 19 37
24 17.20
7
19.36 9
18 9B
122 347 □M
... 3 44 OR
"S 3.23 ok |
1001 1       1001.5
07
QC-01-
0 080           371
5          98 C B5
09             O.QBO          509 QC-01-
11              C.OBO          509
□C-01-
4
IODO 7
1
1000 1
7
1001.1
7. _    980.82 1000.7
9          98'. 49
0.41
045
6
19.8
3
21 5
6
20 7
0
20.3
5
19 3
2 WO
0.462         1 714         18 98
3
17 99
5                62           3 ^6        ok
280 0.462 2 352
260 0.452 2.352
18 00
6                 5                85          3CO       Ok 1695
1000 3
0 62     . 0
ie 8
13
ac-oi-
15
QC 01-
a oao i     397         999.66
0          9B1.48      054
0462          t 834
16 95
16 99
4
4
0.380            516         998.64       999 68      985.OC     1 04
2
146
8
280
280
280
0 462         2 3B4        12.30
3
*.e 99
0
12 29
5
8 486
3
2
1Q2         3 39
79 3.40
129 3 07
J ok
17               0.080            226         998 57      998 97      9B8.9K      0 40       9 99 QO01-
0 452
’9              oceo       419         997.53       997.96      9Mb.47     0.44       9 50            200              0.462
1.506 849
1 936 7 57
[ 7 568               2
109 2 83 Ok
140 2.52 ok
Water Works Design and Supervision Enterprise
HI
Apr,I 2016Ministry of Water, legation vd Electricity 
Volume- VII -Final Operation, Manteunte arid Safety Manual
Dabus «rbg£rtwn Study find Design Project____________ _____________ Parrt 11- Imgaflon and Drarage System
Annex 3 Rating Curves of Canals Regulating Structures: a) Rating Curves of HR structures on LBMC
H’Q Curve
HR01 for SC-1, Q (max) =0-434
d-Q Curve
HR02 for SC-2. Q (max) =0.11
'Al'alf- ’        " -<S l>L!M3” d ! Jiuoerv nr F-l’Crra-nge
AlinMinteby of Waler. Irrigation and fledncrty 
Volume- VII -F rm I Operwbcr. Maintenrwico ard Safety MaruaJ
Dabusjmqalior Study and Design Projed____________ _____________ _______ Pant jj-Irrigation and Drainage System
HR03 for SC-3, Q (max) =0.504
H-Q Curje
HR04 for SC-4 Q (max) =011
Aa*c ‘A'ti’<S
r
Ht.‘K   ;   s'ij
Sucervisian nlerpr tc
33Dl!XtU £ u MutOJlo
UiUhjJj**? 4ll JA
Mj<L)S34
Ministry  at  Wtftr  Irrigator  ind  Electricity O^birt -n-gation Study <M Design Project
Vat;n*e-V1l Fruit OpenrtJcn Maintenance and Safety Manual _ PTrt II-frr>gjbon and Drainage Syatem
H-Q Curv*
■ lirw
HR05 for SC-5. Q (max) =0 534
H-Q Cutje
o>
-■*■.• .'I if."I '■. 11 i
HR06 for SC-6, Q (max) =0 526
Wa> A’arHs Dcs-gr j -1 Suse^ s«dn |- i'ijrp’5e
,
Atm ;ir.’? 6Ministry of VVatar, Irrigaton and Electricity Dabus Irripatcn Study and Design Project
Volume- VII - Final Operabon. Mmntenanco and Safety Manual Pant fl - Irrigation and Drainage Sysl«rn_
H-Q Curve
HR07 for SC-6. (max) =0.11
H-Q Curve
GaT»                   , m
HR08 for SC-9. Q (max) =0 108
H-QCurve
seu
noq -'to lie DU 0?
0 25 0_W nr OO 0 45 I’-fj 0 55 DM1 0 'A D 70 OA 0 80 0 85 ‘hl
Dif* Dp«r-r t «■.
HR09 for SC-10 Q (max) =0.678
Wa:er Wr-s z- a-c Sjoery ’ ■■' - ■ erc-se
Air Z,'6I
I I. I
I 8
8
! t i
0
0
0
I I
I.
I
8'
Mnislry of Water, Irrigation ard Electricity 
Voiwne- VII -Fna Operator Maintenance nn-d Safety Manual
Dabus In-igation Study and Project ____________ __________________ Pant II-Pmgaton and Drainage System
H-Q Curve
1 «M
fin- icPi n.i:rate -jjq D.25 n n □ i'i ijtft ci.te d.50 OJJfi n«c- urA »jn CRTS 0-60 0-B5 ci1 'XI *’to trw ins i.in E n i jtl i J1» &••• Op*«Lrti
HR10 for SC-11, Q (max) =1 194
H-Q Curve
HR 11 for SC-12. Q (max) =0.831
H-Q Curve
E S!
n ISO DIM
0  I4Q 0 120 0.100 DD6C DOW
CrtU 0 02C oooa
a.DC OC6 n jfl IJ Vi DJO £!■ 2S ciJO Q A 040 ©te i'i r/) OVi
HR12 for SC-13, Q (max) =0.171
<    ■■ Wor^s De? 4- gre S Trvrp D ■;,2'! 1
Aqr|M«nstry gf Water frngaton and ElecUtrty
Dabus imgaticn Study and Design Project_______
Vc^me VII -Fnal Opera h©n, Martenarce and Safety Marwal Pint II- Irrigation and Drainage System
H-QCurve
pE*o
CO -H
W
hr
W  ■!
“ 6
£
2
□
Gale Opening, m
HR13 for SC-14, Q (max) =0 109
HR 14 for SC-15. Q(max) =0.109
H-Q tunje
i
HR15 for SC-16, Q (max) =1 284
b) Rating Curves of HR structures on RBMC
Wall’- ‘ ”-3 5 c i rd SupnryiS'C'1 ’ ^‘Z ■;■•
r
Ar.< 7"TjMinstry oTWhS^. Jnipatjoni ancf Flecliicty 
VohJme VII —Final Op-Eiritinn, Mawftfinance and SgFfFfy Manual
Dabus Img-V^r Study and Design Project __________  ________  Pant II- Imgjfon and Drainage System_
H-QCurve
■o
13 r
HRQ1 for SC-1. Q (max) =0 43^
H-Q Curve
Gsre Opening m
HR02 for TO1.Q (max) =0.093
H-Q Curve
y.T
zjf+t —
HR03 for SC-2 Q (max) =0 431
■A'aicr VVnrks Duj.iqr and Suce^iMur Fn-i luiss
H6
Au* Z1QVmfelry of Wsrier, Imgatjcn ,ind Electricity 
Dafajs Irngafron Study and Project
Vokime- VTI -Fnaf Operation, Manfenanco and Safely Maixiai
_____
Part I' - lrr»galMjn and Drainage System
HR04 for SC-3. Q (max) =0 496
i. 11*
HR05 for SC-4, Q (max) -0 734
H-Q Curve
0 lift
1
Gail  DpefWif. nn
HR06 for SC-5, Q (max) =0.106
Water WrkS Dos q- and
^cervis nrerz
r
,s .-!
Ao" ?D‘&RiJ*i
Mjm 0.14
Dluhiqtml/i Mm I Ml
Ehuharcem'/t Mjk
Minfelry of Water, Irnpabon and E l«*ctric*y Datura Irrigation Stutfr and Design Project
Volume VTI -Fnal Operation, Maintenance and Safety Manual Parrt II-rrrMjabofi and (Jranage System
H-Q Curve
GrM OfwnlHk m
HR07 forSOS. Q (max) -0.364
H-Q Curve
i? mi>
HR08 for SC-7 Q (max)-0 238
H-Q Curve
Ml
h*
HR09 for SC-8. Q (max) =0.84
Z.'orks Des gn ar’d
SupC'V . nn F me t    rj?
r
Ac 7.1-6Uintetry erf Water. Imgatjcn and Hedrerty
Votime VII -Fnal Operation, MamfFrance and Safety Manual
Dabus Imgabon Study and Design Project ___________  _____________ ____ Part IN Irngaton and Drainage System
H Q Curve
OHO--------------------- -----------------------------------  -
Wa'cf     Works     Dti     a--j Suei*^ 5 on I nlcrp' ■
AtH 77-6

Summery

Dabus Irrigation Project Summary

Dabus Irrigation Development Project Summary

Project Overview

The Dabus Irrigation Development Project is a large-scale irrigation scheme located in Benishangul Gumz National Regional State, Ethiopia, about 55km east of Asosa. The project aims to develop 9,100 hectares of irrigable land through a comprehensive system of dams, canals, and drainage networks.

Key Components

Infrastructure

Diversion dam structure (head work)
72.35km of main canals (Left Bank and Right Bank)
25 secondary canals (25.659km total)
124 tertiary canals (178.38km total)
926 Flexible Gated Pipes (Flexi flumes, 497km total)
19 Night Storage Reservoirs
Extensive drainage system with interceptor drains

Water Requirements

Parameter	Value
Net Irrigable Area	9,100 ha
Peak Irrigation Requirement	153.05 mm (February)
Maximum Irrigation Interval	14 days
Main Canal Design Duty	1.4 l/s/ha (24hr operation)

Operation and Maintenance

Key Maintenance Activities

Regular greasing of gates & valves
De-silting of canals and drains
Repair of embankments and structures
Vegetation control
Road and ramp maintenance
Flexi flume repairs

Maintenance Categories

Regular: Weekly/monthly maintenance without system disruption
Periodical: Annual repairs during non-irrigation periods
Special Repair: Major renovations like structure replacements
Emergency Repair: Immediate response to breaches or failures

Organizational Structure

The project will be managed by the Dabus Irrigation Development Enterprise (DIDE) under the Benshangul Gumz Agriculture Bureau, with responsibilities divided between:

Operation Department: Water distribution and scheduling
Maintenance Department: Infrastructure upkeep
Water Users Associations (WUAs): Local water management and conflict resolution

Key Features

Flexi flume system for efficient water distribution (98% efficiency)
Night storage reservoirs for continuous water supply
Comprehensive drainage system to manage excess water
Detailed operation and maintenance manual
Farmer training programs