V Ixptftmept THE FEDER. IL DEX IOCR 171C REPUBLIC OF ETHIOPIA MINISTRY OF H ATER RESOURCES A YSHA BASIN RECONNAISSANCE PHASE MASTER PLAN X olunii' IV: Water resources A- Hydrology B- Hvdrogeologs ('-Danish Hsdropowet I) Irrigation Alter ResourcePreface The dry basins rc«jnna;tsancc phase study has been conducted by the experts pulled cui from the basin developmcnl study department Data collect ion and rapid field visit was made for three dry basins simultaneously viz* Ogadcru Aysha and Dmakil between June and August 1999, then the report production was almost compieied m May 2000. The icpoil is divided in lu Al volumes nude up fiuiii Wuika Cvnulktcd Juj lhjj die study phase Each volume has sections depending on rhe derails of the sector X olume I Volume !T X oJume 111 Volume IV X'olmne X Volume XT Executive Summary Natural Raourees Agriculture Water Resources 3ociw-E<onuLny Environment Ltsi of evperis produced these repon are; hyiiacticw Yuayew Abebe Gulma Solomon Mcngistu Xmire H Selassie Eckaluiicd Smtaychu Tiiahun Mckonner. Worku luvas U .Mariam <rirum Admasu Belay Tcgcgn Wubshet AlemaX ehu .xblkcl ti Mtfdhui Go«hu kcheck Citolojy and X Imeraiogy Soil survey and Land el a!ualien Land use Cover Foreeiry npd F nergy Wildlife and Touristic Agronomy Livestock. Range land. Apiculture and Fishery Hvdroloev Hydrogeology Dams and Hydropower [rrigatifn and Drain .g-: CkulcthnKiv arid iruj a^n U'.".n, Av»*k.ulrural knniiniii» Mdaku Abebe Demography Geiachew Eeyene Sod and Waler Conservation Yeyesus \V«i Bckek Environment and Envirtrnmenu! HealthDry basiu shirty project Wnafcil, Ogaden and Aysha.' Hydrology report, 1999 THE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF WATER RESOURCES AYSHA BASIN INTEGRATED DEVELOPMENT MASTER PLAN PROJECT RECONNAISSANCE PHASE HYDROLOGY 4 l>Ck'emticr. I99 ) Mipiscry al rewurcm of Eihiopij 8«pn de* ckipniem dcpuwlircnlDry buirti study project OwnkiL Oga4cn wd Aysha Hydrology report. 1999 TABLE OF CONTENTE5 CONTENTS EXECUTIVE SUMMARY J 1 OBJECTIVE ... PACE ..._ii 'irilBIIIIBILIIBIlBI-llILIIJIMlMli 2. LOCATION AND PHSYIOGRaPHY 1 OVERVIEW OF PREVIOUS STL DIED PROJECTS. l : EVD5A- Master pl for THE DEVEUtfMt M uf WRFaCE u An r re sources pm the Au ash BsSiv HALCElOW IW... 3 J EVDSA. Vb JiTEfi RESOURCES DEVHiWMFSI MASTER H-AN FOR ETHWflA. U A PCOS. 1^90 1 DATA AVAILABILITY 3 I MFTECROLOGJCAL DATA 3 2 RIVER FLOW DATA .. ■ ■riiriirnth iirm HLiikii-ii.i! illBIIKIIKII III .1 .il&Ai. ■■ 3 3 SEDIMENT TRANSPORTATION DATA 1.0 CLIMATE — J I GENERAL DESCRIPTION .. 1FWI FflBI IBII ■■■ Bllh.l •IF7f IIISIIT II IIBIIidMIMIfe. >1 44 j 5 < fr ■ rilHIIII.IMIUl.lUi <v 4 2 CLIMATE OF THE BASIN 5. precipitation................ 1IBII -II IIBI.11-11 II. '■■fF“i-iir iniiBii IIBIIBI III IIIBII .1 5 I NETWORK SPATIAL DISTRIBUTION OF METEOROLOGICAL STATIONS AO SURFACE water resource ••■■"■r'lmniniiimiiriiKiuiuiui... .10 T PROPOSED PROGRAM FOR II PHASE ACTIVITIES. LOGISTICS AND MAN POWER RFQl IREMENl.ll T I PROPOSED PROGRAM FOR II PHASE ACTIVITIES 7 2 MATERIAL and man power requirement S. CONCLUSION AND RECOMMEND aTI0N„.................................. REFERENCES----------------------------- --------- 12 Miriifliy oi waler khunics of EmwfHa Bd^iri dr*toclufimcfiE Mud) departmentDry basins study prt-jccl *Duukll. Ogiden. and AysAfr TABLES Hydrology reppn. 199V iar[ f i material and equipment requirement for thf hydrology section TA RLE 2 MAN POWER REQUIREMENT FIGURES FIGURE I TOPOGRA PHY OF TH E fiASIN PAGE i I PAGE r Mintitry of water resource! of Ethiopia 411 Bavin dc-hclopment stud) departingrvtDry bums study prdjrCI /Dflft*kil. OfHkfll arc.l Aydw Hydrology rcpon. IW AflaMyUIlQRjLfrD ACRONYMS BSH Hoc semi-and climate BWH; Hot arid climate E.C: Ethiopian calendar E VDSA. E Lhu opian va I ley development study AuLhonly FAO: Food and agriculture organi sation GPS: Geographic positioning system HD: Hydrology department IGAD Inter governmental authority for development 1TCZ Inter Tropical Convergence Zane m a.s. I Meter above sea level m. b. s. I Meter below sea level MWR£. Ministry of wiier resource of Ethiopia N"MSA NatLonaJ meteoroJogical services agency Qb . Quantity R I f Relative humidity UPS: Untnierafflable power supply WAPCOS; Water and power consulting sen ice WARREDOC: V ater resources research and documentation centre WMO World meteorological organisation Ministry of waler rcuduKcs of Ethiopia ELitin. iteiclupnifnl study dep-JfinicntDr> baiini Mudy project ■'Danakil, OfeAden and Aysha Hyrirotojp r?|»n. J999 L INTRODUCTION This Lb the revonnaissancc study report for Aysha basin master plan development. The basin L th; sub-catchment of the Awash ba^n. HALCROW. IW In Awash river master plan study, this basin included in the eastern lowland /dry land-. Al the reconnaissance level of the study almost all reports related to the basin hate been reviewed Section 3 gives the information about w ater resource development study projects of the basin |.| OBJECTIVE The objective of the hydrological study was to estimate the potonnal water resources of the basin which will be give tight to water resource development of lhe basin In this aspect lhe reconnaissance phase Of the Study scarred The major goal of this reconnaissance lev el o! the study ios to ■ - glhet the available related informations in side and out side of lhe basin. - rex iw the studied projecismside the basin, - give guidance Io the next phase of the study 2. LOCATION AND PHSYIOGRaPHV Aysha basin situated between tO to I u l' J lat and 42" to 4?' long The attitude in the basin varies from 1700m south of the basin to 575 m north ot the basin, It is situated in the north-eastern pari of the country bordering with Djibouti Republic to lhe lop and right side of the basin, and it is a pan of Awash basin. Completely founded in Somali regional siaic. in Shmdc zone I ig I showv the tpography of the basin The area of the basin round to 4312 km‘ Suetnns like Biyc Guigcr. Kobe, Seblosa. I asarat. Gvrbalc and Dbeder are flowing seasonally in lhe basm with defined river courses Mmiurv of waler rcwuirer afEthiofhi Baurt cH". clop mem study dqMnibciiiDry buial study project 'Daoaki I. Ogaden and AyUli Hydrology report. 1999 Figure 1 topography of the basin Mimsin of water resources of Ethiopia 2 Basin Jcs c lupmcni xiudy department■* Bosin mop ot , Figure I. ■: 1170000 __ ____Iftternotionol btnjndory ____ Basin bauMor, ____________ Seasonal stream . . . 1*150000 I 113WW TI F * I I i l!IWW WOW 2«om 2WW0 22NN io-2'ir 2SOOOO ♦MtTDf) tHSiM nudy projKl Owakil pga-gen -md Aysjuy 3. OVERVIEW OF PREVIOUS STUDIED PROJECTS E^drDlogj report. W J ] EVDSa, Muter plan for the devdopmem &r surface water resources in I hr Awub basin, HALCRJQW, im [fl lhe report zndicaLed the water resmm of the Awash basin its a whole. The Aysha basin founds in lhe eastern sub-caLchmcnL of the Awash basin, with low rainfall and barren land. The basin situalcd into 2 rainfall regimes 'based on ihc Awash twsm rainfall regime classification. [n Awash muttr plan siudi report ihrere wvs no indication abam the water resource potential of Aysha sub calchemenl 3.2 EVDSA, Water reinurcei development master plan for Ethiopia, WAPCOS, 1990. The study mJ masterplan pieparalion was Io comprise of three phases The inception phase. the study phase and indicative maslerptan prepaTaLLtm. In the lirst phase of the report preparation the analysis of all implemented projects wrch respect to hydrological and geological features Kd I DC mot ion. adequacy of spillway capacities irrigable areas and land Suitability. hydropower asspects and cnvimmenUJ effects wnp discussed. [n the intrim report, the studies have been mainly directed LowarJs Lhe preparation of the indicative master plan Mbit iff the studies carried out were used for the tomtuldiion of ihc plan and wmc or them served is useful guidelines for detailed planning The final report marks finalizauon of ihc preliminary master plan. Ail identified irrigation and multipurpose aswrll as exclusively hydrpower projects have been described The projects recomrnded fur EVUlion during the neM SO yeiH in phase manner have been fncntiflned Fhc lirul report consists often volumes. Minjiln gf waler rcM!iurt:rt of t Eh il^iei Barn dcvdapmein Mud% dcp±nni^n5Dry bums study project /Dwakil, OgidCT gid Ayilw Hydrology report 1999 In the study identified 4 major basins in the country Aysha basin belongs to eastern basin Based on updated isohyets, each river basin has been subdivided into different rainfall zones. The purpose of zoning is to understand the spatial variability of rainfall, identify areas of higher suitability for nater resources M inis-iry of water resources of Ethiopia 4 Basin developtTkEnl tfudy departmentDry bMifiE study project ■■Dunikil. OfladEn and Aysha1 Hydrology rrpon. 1^9^ x data availability 3.1 METE ORO LOG IC aL DA TA Source ot all meieordogtcd data coul d be N M$A md FA O Tn thu rcpon i» det ai led ijlf wniffikjo regardi ng ihc climate of the bSMD U coll ect ed. For general infunnaiicm annual vaJur rf basin dirtWK chuacterisLics is nwlvded in lhe report /HALCROW, 1 3.2 KJV£R FLOW DATA In Aysha hjstn no measured streams exists, therefore the flow d-aui from this basin should rwi be expected- 33 SEDIMENT TRANSPORTATION DATA Since the basin have no perennial srreams which can be quantified the amount of llcm, (low measurement couldnot fordone Beside to this the eglirnanon of sediment iransponAUun from ihese seawnaJ streams have been impo&sibk. Ministry of wjmt resources of Ethiopia Baiin ^elopffitni study depanmcnitKiinntikly projKr/Duuki I, Uj^den and AyOi* 4.0 CLIMATE 4.1 G EM ERAL DESCRJ P l IOM Hydroxy report. I»» The most important elements fix both agriculture and hjdrofogy are precipitation, tempera LUre and evaporation Prtdjriwion data are an important inpui in waler resources Studies, in particular for the sLudy qf the rainfall-runoff process through which if determined how much runoff results form a certain amount of prccrpilaiion on different catchments The other climatic elements .Temperature, humidity. wind speed, radiation and sunshine hours are required Io estimate pLm! waler nquincmenttand reservoir evaporation Frt the tropical bell. vtriaiiMk of chmale during tihe year are largely associated with mar rq-sca It pressure changes and lhe air flows related to these changes The pressure changes QTir generally driven by Lhe annual oscillation of the Inter Tropical Convergence Zone TfCZ- In February and March Lhe enure country is v i rurally dry The souLhern pan oi the country is Cos cred by lhe WC1 itfinn: in April. In may the bell motes northward, and in June it extends further northward, leJV tng pan of lhe south and south eastern regions remain wet during July and August. In September, the be II moves southwards and this movement is accelerated. leaving the n&nli and central pans dry MiJiiilQ.- of WIDCT CrSuurdti dE* ElhbOfhl ft Hnvirt dewclgpmefii sredy depamnemDry wns srudy projeci ■Dmakii, Og-iden and Ay aha 4.2 CLIMATE OF THE BASIN Hydrology report. Aysha basin is included in BWfi thus arid chmatey This basin is barren 10 sparse segclaliun with mean annual rainfall of 325 mm (AyshaJ and ] 85 mm {Da welc) 'HALCROW. 19® 9 The maximum and minimum daily temperature are m (be range of 31.3 and 18-2 C. mean daily temperature over the basin amounts to be 24.8 "C Mean wind speed over the basin is 2 J m s, mean sunshine hours 67 % and mean of tmaJ radiauon rounds <0 468 0 caLcmday The Altitude evaporation relationship region wise expressed by formulas As the Aysha basin is a part of Awash basin, rcgionaiizaiion of evaporation bused on data collected for Awash master Plan The basm has regional relationship for estimating evaporation E = 3831 - 0.979H where H - elevation E ■ evaporation Since there is no adequate data for estimating PET of the basin, this task left for the II phase of the masterplan study Mimiiry of *ater rcwuKes of Edimpia 7 Basw Sev-Biqinietu study depannicruDry Iwm* igudy projKf 5. PRECIPITATION ajl -d Ayah* Hyrfr^Jpgy report.JW The service agency released u-n i^h>eLd map 1.2,000,01X1. which is clearly depicts Che rainfall distribution of Ethiopia. Aceordiflg to the map mean annual rainfall m thr basin is in chv range of 400 mm Where K in WAPCOS report, bused on wpdjred isatievts. each river bairn ha* been subdivided mlu different rainfall times The purpose of zoning is W understand lhe spatial Variahili^ Of rainfall, identify IKU of higher suitability for water resources development and to work ou1 correlation Between various hydrological parameterseg rainfall and runoff Zone I Rainfall less than 400 mm Zone II RainfaJJ between 400 and 800 mm Zone tit Rainfall between 800 and 1200 mm Zone IV Rainfall oetween 1200 and 1600 mm Zone V Rainfall beiwecn 1600 and 2000 mm Zone VI Rainfall above 2000 mm Aysha basin gees mon; ramfall in US southern pan time 11 . while lhe north and central JNJrt W I geLS rainfall amounts leis than 400 mm As indkmd by dfffireni studies, the basin exhibit wiiform spatial! divibution rainfall umoujit The jemptiraL dimbuLmn of rainfall also shows umIumiiny as wen. But bused on info rm an on gaihervd from settlers of ihe two towns Aysha and Lkucle during field visit m the hmm The group have able to observe the scarcity cu water due 10 the rarely occuranpe of rainfall. According hi the first hand information lhe ram fall after some three years. M in iwr>- ctf wafer fttaiitcs dF Elh lopia i Ravia development Hwty fcpartmtmDr) tw in» project ZDiflakll. OgaaXn ajid Avs-na. Hvdjratogy reporr IW9 II NETWORK/SPATIAL DISTRIBUTION of meteorological stations i'he present network of the basin is ikH hi tiw SUlfle <jf fulfilling criiena declared OV ft MO I tit um of the nefiMrt is to provide a density Mid distnbuLLon of stations io a region such lhac. hj interpolation lxiw«n data sns Of different siations, Jt will be possible, for practical purposes, to determine with sufficient acCurtCy the Statistical parameters of (he bsK hydnjlugbraf and metcoToJogicai estimates any where in the rejLgn ■WMO, 1994 The WMO admes lhe following minimum densities of rainfall Stations for rhe differed physLogrphic uniLs Region Minimum density, imogt/km'/gauge/ Temperate S1 rdi lerranean and tropical zones Flat areas 600-90HJ MomtsincKB areas 1 DQ-2?U Small mountsiflflW is lands {*20000km‘j 25 Arid i polar zones 1500-IOOGOO [n Awuh niSJtflj plan leporl indicated [haL tn Aysha basin exists two mcltWrulugical stations MK hi Aysha «W> and [he Other is in tku.de town According 10 the WMO setup of stations density the basin, satisfies iLhc minimum requirement Mcnairy oF *a£rr rawurcies uF Er h lufiu Basin Jcveiqpjneni study ifcparuHcni.Dry Iwim wudy project /DanakiL OgadcTi and Aysha.- 6,0 SURFACE W ATE R RESOURCE Hydrology report. 1999 In [he basin flows seasonal screams like Bjycr burger, Kobe, Scblusa, Lasarat, Gerbalc and Dbeder The climate of che area indicates scarcity of rainfall ai low lands, inconsequence of this is small amount of flows. Due io scarcity of drinking water lhe people in the basin nedds Io fetch it from a very far distance Sometimes the supply of water assisted by drilling of boreholes around lhe villages In some places pastonalists construe! ponds or bircas to harvest rain IO give drinking water for I heir cattle. Hence in lhe hosm drought occurs frequently , at lhe lime of visit of the area Che rainfall occurtd after 3 years The surface water amount is less due to rarely occurrence of rainfall in the basin The less in amount and rarely flowing of streams of the basin to depend on water resource could be difficult Moreover on the WaPCOS report indicated thai the surface water potential of the basin is negligible Ministry Qfwacr rcwu^H of Ethiopia Uasut develdptncni study departmentDry bums s-tudy prtyKC /Danikil, OglOCH And Aylhfr Hydrology rcpon. 7. PROPOSED PROGRAM FOR II PHASE ACTIVITIES, LOGISTICS AND MAN POWER REQI 1REMENT- 7.1 PROPOSED PROGRAM FOR H PHASE ACTIVITIES For lhe II phase of the study, h would be better to consider these Climate - In upgrading and installment of meteorological stations die low land should be covered by rhe program. - Collect daily rainfall record for selected storms; - Produce isohejiai maps for mentioned precipitation series scale 1.25OJJOLK - Based on daLa from selected recorders and maximum annual daily data, rainfall intensity duration relauons will be developed. - Calculate the average monthly PET with available climatic series. - Relation of average annual data of precipitation and PET with altitude wilt be assessed II' possible, relations can be used io estimate average values for areas without climatic stations surface water - Estimate the annual runoff in the catchment based on the available precipitation data, - Regionalize the flow senes based on the rainfull-runoff relation, - Survey irrigable sites based on available water resources Ministry of water resources of Elhiopn Bran deselLjpfncfli -sDud> depanmentDr,bKin-5 acuijy jwdjecI ■tJwfcjl, O^ader md Aysh*. 7,1 MATERIAL AND MAN POWIR REQUREMLNT Ta Ur J Material and equipment rcfulraaent far lhe hydrology section Hydrology report. I*W Np hem descripnon unit Qiy Remark 1 ii J 4 i 6 T 3 9 10 11 1 i: 1 13 ^office with Ebe necessary fac iirtks Leveling instrument Ahimeter Campass PlaJiiineier GPS PMfaabk pocket sire1 Compuicr processor greater speed and capacity Printer LaserJet umnterepJnbJc power system IPS Personal nems StiEK.miry mllcrials Topu Map Vetuck Stl nr nr nr nr nr nr nr J 1 1 J 1 1 1 1 Ls Set nr 1 Can be shared with other scl-lkm^ in waier resource group- For all skdkd man power w hich are participating in die next phase of ilie >udy Seale i 250.DQ0 1 staiicm wagon lor super viswn J pick tip lor field work TabkS Min pauer requirement No Man power Remark J 3 4 Senior hydrologist Hxilrnkigisl Hydrographer Driver ____________ ] 1 t 1 V^ho has an experience on water resource of arid region W ho participated m writer resource* related project-, Vblto panic ipitied in water resourcei related projects j class drning license and good workuiE experience Ministry or^ucr resources of Ethiopia 12 Basin orve lopmen i study depidmentprj, bums study proyKi /Danabl. Ogiden tnd Aysha 8 P CONCLUSION AND RECOMMENDATION Hpdrotogy rrpcn. J 999 At this level of the study it was tried IO indicate the available information regarding waler resource oi the basin. As n was known adequate information is the access io detail investigation ol any basin master plan study. In this respect the Aysha basin has no adequate information. which can be helpful tn execute lhe master plan study of lhe basin. - Upgrading the existing meteorlogical stations, inorder io get better in formal ions for lhe next phase of ihe study. - Tl»v integrated master plan study of the basin in lhe future should indicate all lhe water resource potential of the basin Minisriy of *awr resources of Ethiopia TT Basin de.eiqpmcrtt Mudy departmentEky bmni irud> prgjea /DanajkiL Ogxfcn and Aysha Hydrology report, 1999 REFERENCES ] EVDSA,. 1990 water resource development Master plan for Ethiopia /water anti power consultancy services, India Ltd./. Vol. IlJ 2 FAO. 1977. Crop water requirements. food and Agricultural organization and drainage paper No 24 3 FAO.1997. Irrigation potential in Africa a basin approach. 4 HALCROW. 1989. Master plan for the development of the surface water resources in tile Awash basin for EV PSA, Addis Ababa 5 Lemma Gonta. may [996. Climate classifications of Ethiopia, Addis Ababa. Ethiopia 6. IGADD, 1990. Forum on environmental protection and development of sub regional strategy to combat desertification. Vo], [J 7 UaRREDOC. March J 996. International works shop, water resources management in drought prone area. Addis Ababa 8 WMO. 1994 Guide to Hydrological practices. NO 16B. Geneva. Mimsiry of rtMwrccs of Ethiopia. Bavin development vtudj departmeniMowtn- of w»tg Resources. 8w DevcfognKnLStudy Pff»OTP<T»r Aysha Basin R,cc<wuissarice_Eb Kg_5lydy J THE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF H ATER RESOURCES AYSHA BASIN RECONNAISSANCE PHASE MASTER PLAN \ olume IV; Water resources A- Hhdrologs B- Hydrogeology C-Danis & H>dropoiter D-IrrigationTable of cntents 1. Physical description.....................................................—...,3 2. Geology and geological history........................................ 3 2 1 Quaternary deposit......................................................... -..................3 2.2. Magdala group......................................................................... 4 2.3 Amba Aradom formation (upper sandstone).............. ............ 4 2 4 Afar group..... ................................... ♦................................. ..... 4 3. Hydrogeology of Shinile Zone (Aysha sub-basin)........4 4. Water quality....... ...... ................. ................... ....................... 6 5. Conclusion.................. ..... ........... ......... ................................ 71. Physical description Shinile is a zone located at the north extreme of Somali regional state Aysha a small Woreda town, Byo Gurgur. Adigala, Andibiyu and Dewele are small towns found in this zone The area lies mostly in the rift valley and is disturbed by uplifted sedimentary and latest voicamc hills The plain is covered sometimes by bushes and at other times by grass and termite hills as it was observed on the way to Dewele area. 2. Geology and geological history Aysha basin is covered mostly by Magdala group and quaternary deposdes. The geological history of Aysha basin begins with the uplift of the Ethiopian swell (hat was followed by eruption of the trap senes and much later by rifting Quaternary marine deposits are known along the Red sea Coast, the Danakil depression (in the nft valley) The property location, and rock types of each series and formation is described as follows. 2.1. Quaternary deposit. It covers the plain area found South of Aysha and East of Jijiga area The main formation of the coral reefs includes fossiliferous limestone with minor clastics of conglomerates, sands, sifts and days (Tesfaye Chernet, 1993). This formation is the latest of all that were deposited in the basin Conglomerates sands silts, clays reef limestone Afar group Basalt, subordinate acid lava, and ignimbrites Magdala group. Rhyolites, trachites, trachytic tuffs ignimbrites ' agglomerates, basalts Amba Aradom formation, clay silt, sandstone conglomerate »■ -Figure 1 Shinile arsa stratigraphy As observed in the stratigraphy shinite area has more young deposits when compared lo Jijiga area 2 2, Magdala group The Magdala group consists of Rhyolites, trachytes, trachytic tuffs ignimbrites agglomerates, and basalts. 2.3. Am ba Aradom formatron (upper sandstone) It is comprised of lower cretaceous deposits including clay, silt, sand stone S conglomerate (Geological map of Ethiopia, V.Kazmin 1972) The sandstones are vanegated quartzose sandstones of fluvial and/or littoral ongin (60-150m). Amba Aradom formation is a cliff forming, highly latenzed formaton (Tesfaye Chernet. 1993) 2.4. Afar group This group includes basalt, subordinate add lava, and ignimbrites. It is found mostly in (he shinile zone The ignimorites are well jointed in most cases and massive in some cases it belongs' to the upper tertiary period (Geological map of Ethiopia, V Kazmin. 1972) 3. Hydrogeology of Shinile Zone (Aysha sub-basin) Ahen referring to the Northern part of Somali regional state there are three mam formations m the Shmle zone covering most of the area The Afar group covers targe part of the dry basin area in Shinile zone It is dissected mostly by East-west trending faults and occasionally north-south trending faults (Geological map of Ethiopia, V Kazmin. 1972) This senes includes basalts ferrobasalts. Hawaiites with some silicic centres near the top and interceded unconsolidated sediments (tn a total of up toabout 1000m) Because this basalt Is fresh and highly jointed, rt naturally has a high degree of permeability II also has a high productivity where recharge and topographic positions are favourable A borehole 60-km south west of Aysha yields S i/sec with a draw down of only 0 7m (Tesfaye Chemet, 1993} The Amba Aradom formation is lhe second largest formation thai is highly latenlued in some places in the north like in the area around r-fagere Selam where it ads as an aquiclude below the Tertiary volcanics and causes a spring line in between. In other praces where it is not latenfaed it has high permeability and produces a large number of springs at its contact with the underlying shales. In the southern ana eastern parts of the country, the upper sandstone (Amba- aradom formation) doesn't show latentization and is an aquifer of high productivity {mostly producing springs). Its high permeability is a result of moderate to coarse gram size, loose cementation i limited shale intercalation. The quaternary deposit found south of shinile doesn't cover the area continuously 11 consists of limestone with a high primary as well as secondary porosity and permeability. The clastics of conglomerates and sands can also be important aquifers if found with a considerable thickness and cover large area According to the Hydrogeological map of Ethiopia, 1993. there are three major aquifer suodivisions Extensive aquifers with intergranular permeability, extensive aqmfers with fracture and/or Kanstic permeability, mam geothermal areas wilh common occurrence of thermal ground water in fractured volcanic rocks and subordinate unconsolidated sediments The first type of aqurfer has hrgh productivity It covers the southern and eastern part of Aysha town Most of this formation gives a ground water wilh total dissolved solids ranging from SOO PPM to 1500 PPM. From the wells drilled from 1972 to 1986 only 50% of them are successful and is supplied by these wells The average depth of these wells is 90m and the average yield is 5 96 l/s The deepest well dnlieo in the Zone is 133m found atthe Shinite Military camp The static water level has a range of 11 m to 72 m depth as observed in the record In ffits Zone it was observed that deep welts seem to have higner yield if productive. The second two types of aqurfers have moderate productivity with the geothermal aquifer having high productivity too. These two cover the area found west of Aysha town Tn addition, the ground water in these two types of formation has a total dissolved solid of 1S00 PPM to 3000 PPM There are also some strips of moderately productive formations found west of Aysha tc-wn There are a lot of fractures trending east-west that are important for ground water development. The recnarge estimate for this zone is 50 mm /year as shown by the Hydrogeological map of Ethiopia In this area there is no geophysical investigation was recorded dunng this investigation. In general, the dry regions having limited or no drainage have limited water resource that can oe used for the society and population of cattle Even though the rainfall in the area is known to be below 500 mm. it rs expected that some amount of percolation is possible Thus, limited resources can be fauna m the area by performing detail investigation. 4. Water quality It IS Obvious that dry areas have high evaporation rate, which leads to water containing high concentration of dissolved solids If it rs surface water it leaves encrustation like calcrete When there is ramfall. rt percolates down to the ground water system with the dissolved solids. This in turn leads to saline groundwaterIn addition teaching of rocks by percolating ground water is the source of high dissolved solids. This reaclron increases where there is young activity volcanic or where the crust is thinner 5. Conclusion Well drilling in the region started from 1957 and went on up to the late eighties as the inventory depicts. This shows that the well inventory is aone before 1990 Therefore, it should be done on all wells found m the region. This applies to the pumping test of wells in the region too. There were only limited lest pumping results shown on the well logs It is Known that test pumping results can help to find the safe yield of a well. Hyarogeological map of Ethiopia shows the general condition of the ground water cf the area. Fissured basalt and quaternary Alluvial deposits are the mam racks covering large part of the area with some subordinate deposits As it is clear from the conclusion, (he ground water resource is not assessed in an organised manner covenng the entire region. Therefore, the next phase of investigation should be done to estimate it C It i$ important to do aenai photographic interpretation to identify lineaments and fractures. This can be combined with ongrnal hydrogeological maps. U The well inventory for eacn town including hand dug wells and springs should be done q To know the iitho-stratigraphic condition and identify the water bearing formations it is useful to do geophysical survey Even though it is not sufficient to do the survey, electrical sounding seismic and etectncat profiling are chosen for nydrogeological purpose 0 Prepare contract document for additional test well drilling and test pumpingf] Perform pumping test and drill deep wells where there are no representative boreholes to be test pumped 0 The water resource of the area should be estimated and water chemistry analysis should be made. Thus, it ts very useful to collect the representative water sample of welts and then send to the laboratory q Hydrogeological map preparation of the basin. 0 Finally the report compdaton should be made.—- ---------- "------------- I, IL J < 1 "1 1 igemd Itikhti iqmtT rm iitritiuiirui rtriuirun MtrvlB pngfiKltT lj I .-jjfi afccLirlLr ItLIttU 1ITI FIflCTUII rt£l£lllLITT Hiffl p'Mrtliii’j BYDNCEGlOClOkL SYII0L5 - Ftulll ------- * Ooundfohf nartiMf'.iiiltrrfi difltUn OirrSfMfQnci poitr inH milleftt itriwt r ms? iNFoaiuuaji L« frtftdmlr _ llHtrsgtiMal isusiUfj — -. Iknn Iratar; ___ Ri-fid Rtvir I___ N H u ctdTiEtHii mu .mm tfcomcc of tiiimil cim di iter ____ H«l • T«u > FtlCTBIEI IHCUIC IKES ill SDBDIIIu:! w tap pUKtiiitj II’II ftD!tm DtmriHir (PUBLIC 3? ETHOFIL rstSTiT or i je! lEsgracts -1 H1IAnnex Logistics and Man power Tabla 3 The manpower, equipment and logistics of the project in the next phase Man power Item Personnel Amount Man month 1! Remole sensing expert 1j 2 Water quality expert 1 3 Hydrogeologisl 3 4 Geophysicist 2 5 Driver “2 Equipment |Type of equipment Amount 1 Stereoscope !1 2 Compass ----------------------------- 3 3 Altimeter 3 4 GPS (Navigation) 3 5 "Water Bottle 3 BiHammer 3 Tllalest Compute* with accessories 2 a Field waler sample analysis kit 1 9 Resistivity instrument 1 10 Seismic instrument I^Land cruiser , 2 1 Soft wares Type of equipment Amount 1 Satellite image processing l 2 Resistivity interpretation f r----- 3 Seismic interpretation 1 4 Water quality analysis 1 5 Ground water flow modeling 1 4 “i Field equipment iType of equipment Amount 1 Tent with accessories 3 2 Generators 2 3 Air fan 3i 4 Bed 35 :Martress 3 6 Sheets 3 Tpfflow 3 6 Blanket 3 1 ft Gas lamps 3 10 Paratrooper shoe 2 ■ 11 ■Gowns 2 12 Umbrella 3 Other Amount 1 Topographic Maps Coveringthe area Z Anal photographs Covering trie area 3; Satellite imagery Covering [he areaTentative work schedule of Dry Basin in Somali Regional State Flfnra J: Trttilivc work tchrduk for Somali krtkus*! StateTentative work schedule of Dry Basin in Somali Regional State 2000 2001 ID 1 2 3 4 5 e 7 Task Name Hydrogeological survey Remote Sensing analysis well inventory Water sample collection Geophysical Survey Test putttpLng on existing borehole Preparation of contract document Drill aditional Drilling ana test pumping supervl Analyse the Cicld data Hydrogeological map Preparation Final report Preparation 01 ] Q2 I Q3 |~Q4 Q1~T~Q2 | 03^0* Remote sensing expet Hydrogeofog 1st Water quality expert Geophysldst Hydrogeologist ^■i Drilling crue 8 9 10 11 12 Hydrogeologiet Hydrogeologist Hydrogeologlst 13 14References 1. Geological map of Ethiopia, V. Kazmrn, 1972. 2. Hydrogeological map of Ethiopia. Testaye Clwmet, 19&B 3 Hydrogeology and Wate< Resources of Ethiopia, Tttfaye eft*met, 1993 4 Managing and Developing the Southeastern Rangelands. Ricftard Woodroof 5 South Eastern Rangelands, Livestock Development Preyed, AGROTEC 1974 hfrtuwjy QfWiM fawutm. Burn Devtktnncni 5MY PcMTO»«ll toihLBgtin Jte^mwiwe ft *” shuh; 1 HIE FEDERAL DEMOCR. 1 TIC REPL PLLC OF ETHIOPL 1 A//A7OTU OF HATER RESOURCES AYSHA BASIN RECONNAISSANCE PHASE MASTER PLAN Volume IV: Water resources A- Hydrologj B- Hydrogeology________ C-Dajns Si Ilsdropower D-Irrigation |,\<ncbLtu.*<jFEDERAL DEMOCRATIC OF ETHIOPIA MINISTRY OF WATER RESOURCES AYSHA BASIN INTEGRATED DEVELOPMENT MASTER PLAN PROJECT RECONNAISSANCE PHASE DAM AND HYDROPOWER October 19991 Introduction I I General description of the project area---------------------------------- ------ 3 I 2 Objectives of the storage reservoir end hydropower reconnaissance ■“ 3 studies 2 Previous Studies—--— ....................... .............. — ---------------------------------- ----- — 3 3 Water Resources----------------- -------------------------------------------------------- 4 3 1 Surface water ------- ------------------------ - ------------- ---------------- —-------------------- 4 3 2 Sub-surface flow----------------------------------------------- -------------------------- —- 4 3 3 General Consideration m hydropower development and data needed — 5 4 Derailed work program for the second stage investigation —------------------------- .... 5 5 References------- —-- ------- --------------- .__________________ ________ £ 2Aysha Basin T. Inlrodutlion 1 I Genera] Tt>e Aysha Basin is lociied in the Northern pins of Somalia naliona! regional state The Ethiopian side of the basin his a catchment area of about 4.312 km' The eastern bounding of lhe basin is Djibouti Republic and the test Surrounded by Awash Basin Like Ogaden basin, Aysha basin contribution to the countries water resources is negligible The basin has and climatic conditions and doesn’t have my perennial streams but there are seven dry streams. The mean annual rainfall of the basins is below 400 mm and the evaporation estimated to be above 2000mm per year The topography of the Aysha basin is flat with the deration ranging from 1714 nt.a s I on the high lands where Btyo Kobe and Biyo Gurgus dry streams commencing place and 450 m a s I in the low lands near Kakle dry lake 1 2 Objectives of Storage Reservoirs and Hydropower Retocnaiisinre Studies I. Collection of previous Studies and data such as existing study reports on water resources of the basin, topographic maps with the available scale, transmission line and power Station etc.. 2 Review- and examination of far al J possible reservoir and hydropower sites 3 Making use of existing hydrological study and geological study 4 After the preliminary analysis, inventory of existing and potential storage reservoirs on main rivers and tributaries will be considered to get a first hand knowledge of the sites using capo maps field [rips to accessible dam sites 5 Based on the above activities, accessibility, distance to the national gndi for hydropower projects, and identification of possible dam sites in the basin 6 Preparation of detailed work program for the second stage investigation 1. Previous Studies Preliminary water resources development Master Plan report for Ethiopia (EVOS A 1990) The study carried ou[ by WaPCOS (Water and Power consultancy Services) In this desk study Ogaden basin was grouped with the Aysha and Danakjl basin based on arid climatic conditions 3The three basins. i.e Ogaden. Denakif and Aysha basin were mentioned together in the study as "the Eastern Basins The study was conducted based on topographic maps I 250 000 scale of the basins This study which was not supported by a field trip Io the actual basins failed io indicate contribution of individual basins to the water resource potential of the nation This situation and the consideration of the three separate basins as a single entity shows- that the study could not conform to the standard required for master planning 3 Water resources 3.1 Surface water During the field visit no suitable dam site has been identified The topographic maps available for the purpose of this study were of the scale I 250,000 survey . which is for too small a scale to be of much practical use for dam site selection for ibe determination of the small-scale reservoirs and dam sice potential areas the I 250,000 topographic maps with the contour line interval of 100m, cannot be used instead a 1 50,000 mapping is the minimum requirement for this purpose To develop the available water resources, which is excess run-off from rainfall in the rainy season, river courses have to be blocked in suitable places, forming reservoirs from wtuch water can be drawn for drinking and small scale irrigation in the dry season Therefore, the study could not come up with small scale reservoir and potential dam sites For the purpose of irrigation and hydropower development in the basin, no dams would have to be considered There are some strong evidences that there may not be suitable dam rites However, these conclusions from Such short field visits may not be decisive, the main limitation to reach final conclusions at this stage being again the availability of suitable topographic maps and hydrological data When this becomes available, the (non-existence of suitable dam rites would be verified 3J. Sub-surface During the reconnaissance field tnp it was observed that the dry stream called Biyo Kobe is wade type According ro the observation during the visit, the Local people use the sub-surface flow by using hand dug wells on the stream channel Where rainfall is seasonal and erratic building sub-surface flow dams can be a good alternative for water resource development the more common reason for damming alub-mrface flaw is to store water Wow ground level in the reservoir upstream of the dam As indicated in the above paragraph, topographic map and hydrological dau available to (he study was not the required scale to enable to identification potential sites for sub-surface water development It is however, thought that sub surface dam development is the most economical and technical way to provide water for rural water supply and small scale irrigation development in arid and semi-arid region 3 J Genera) consideration in hydropower development and data need ed- There are two ways of developing hydropower potential The first is to divert the river flow and develop run-off-river type hydropower, and the second is through the construction of a dam far storing water Run off-river type hydropower development cannot be developed on the rivers found in Ogaden basin Because, the rivers are flowing in the wet months of the year only for a few days The remaining option thus is developing hydropower through storage To develop hydropower through a storage scheme the following points should be taken into account I Availability of suitable dam sites - Dam sites can be identified either form small scale topographic maps (1 50,000) or'and by fieid visit The existing topographic map of the Ogaden basin, however, is of large scale 1 250,000 and identifying dam sates reliably is impossible based on this map The expert visited the Aysha basin in July 1999 Possible dam sites have not seen in the Basin - Assessment of stream flows - Due to the absence of Hydrological gagging stations in the basin, there is no a data of estimated annual sediment yield for catchment and monthly stream flows of [he rivers CmcJuwi Due to the fact that rainfall concentrated to- a few days of the year only and it is amount also very small, catchment area of the streams are very small, so perennial streams exist, there-to chose stream diversion as a basis for year-round irrigation development is not possible Due to shortage of water, sedimentation problem and unavailability of sunable dam sites development of hydropower in the basin seems unlikely 4 Detailed work program for the Second Stage investigation 5t Shea already identified and studied should be checked on aerial photographs and with helicopter Surveys. VanOUS characteristics OF the sites will be analysed using appropriate maps, including hydrology h reservoir characteristics, potential generation capabilities in relation to other projects (irrigation) 2 Assessment of demand arid load forecast for export potential 3. CoUectirm of information On sub-surface flow dam in 1 he basin for water supply purpose 4 Sites will be ranked, raking into account preliminary cost per K^'A, benefit for other projects, distance from load centre etc. 5 For the attractive sites, assessment geological and geotechnical properties affecting design of dam, power house and sub-surface dam will be made 6 For previously studied sites, assessment and updating oFexisting data will be made For the selected sites menuemed above, mure detailed studies wilt be including preliminary designs and costing of dams rules house, Sub-Surface danis and accessibility B carryout Kismicity, tectonic, geophysical Survey for foundations at proposed dam sites *3 Investigation for construction materials Reference WAFCOS preliminary water resources Development Master Plan Report far Ethiopia (EMJSA, 1 WO) In this oesk study rhe three basins Aysha. Danakil and Ogadcn named as thr Eastern basin fiBa.-4.-i I>vckmT>gir awfc ftrconnu THE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA MINISTRY OF WATER RESOURCES AYSHA BASIN RECONNAISSANCE PHASEMASTER PLAN Volume 1V: Water resources A- Hydrology H- HydrogroloE? C'-Dam* Jt Ihdropcmer P-IrripjrionAyrlu Dry Bwn Maitg Plan Ptojw Rtvwxtwx* Imgabon A Drunagt Repar Table Of Contents Abbreviation* 1. [nlmiucton............... 2. Back Ground......... Page I 3. ObjCCtlVea .......JJ....M <4........i. ..............4.44.4......4444444• 4 Study Approach 1 Methodology 5. Institutional 4 Policy Aspects.. 6. Need For Development irir■ii 3 3 ■ •rrtH ■ 7. DocnpUon Of The -Study Area. . a i ate < ?l Location St Accessibility .... 7.2 7.3 7.4 7.5 Topography A Land Feature Climate....................... !W lUHsrarrrri Ml itt ■ ■ ■■■■.■■ uaaa>.G-i.i.i.i...s ■ . la.. s... ............ - a -.. JF .9 4 7 8 8 9 Water Resolrce ... AwcmniRE, Land Use 4 Land Cover... ■ -^■FFrr'iriiiMiiiiiiiiiii 7.6 Soils........................................................................ 7.7 Socio-Economic aspects ....................... ................ 9 Potentials For Irrigation Developmcni. ............. j"itrrii i biii Possible .Areas Of Smail Scale Inigaiion Development Sites. ] tl Previous Studies Reviewed II. Dau Gaps Of TIk Siudv................. „........ JO 10 II Il 12 . 14 ...... 15 12. Conclusion 4 Rcvummcndition .................................... ................................................ 17 13. .Annexes I. Field Trip Report............................ II. Tcmu Of Reference For The lsi Phase Study.......................... .............................................. 2R H References ...................... ...... ...................................... .. ... . 15 Map . .. 31 Meustn of W'uer Resaws Rjirei Bwn Devtiopmmi Studui Dcpartmenl January -IXX:Ayihi Dry Buin Muter Plan Project Re&xmaiAMflce Irrigatum A braiflaigc Report abbreviations 1. APS Agricultural Projects Study. 2. CECE Concert Engineering & Consulting Enterpns 3. COSAERAR Commission For Sustainable Agriculture A Environmental Rehabilitation for the Amhara Region ♦. EHDA 5 ESRDF 6 EVDSA 7. ha 8 Ips 9 Km 10. Lft ll.LWF )!■ 13. m.a.s.l East E-iararge Development Agency Ethiopian Social Rehabilitation & Development Fund, Ethiopian Valleys Development Study Authority Hector. Industrial Projects Study Kilo meter Litres per second Lutheran World Federation meter meters above sea level 14. mm milli meter [5. nA* meter cube per second It MOWR Ministry Of Waler Resources 17. MOA M i nistry of A gric ulture IB. NGO |9. N'RDEP 20. PET Non governmental orgarujation Natural Resources Development & Environmental Protertian Potential Evapo-lranspiration 21.REST Relief Society ofTigray 22.SERP South East Rangelands Project 23 SCF Save the Children Fund 24. SAERT Sustainable Agriculture i Environmental Rehabiiitaition for Ii gray, 25. WAPCOS WMtt and power Consultancy Service 26. WWCE Water Works Construction Enterprise 27. WWDSE Water Works Design & Study ntetpnse Munisiry of Water Rwwits Hjvcr Biin Dcvdopmeni Shidws D^irbne-i- January 2000A/xhj Bam Muter Flan Project Reccruixmanix Irrigation ft D^irnge R.q:-ort 1. Introduction Thu study report ia prepared u the result of the reconnnSMncc study conducted by the Ministry of Water Resources, River Basin Study Department under its recently launched project, the Dry Basin Study Project. The project carried out this jtudy program from June 1999 to Dec. 1999 Thu reconnaissance level study is one of the first consecutive studies io be conducted, in view of preparing the final master plan for the basin. And as part of the many integrated development ituin invorporaicd in the study, this particular study report deals with the irrigation A drainage part The study tn general anempis to give the required answers in response to the issues given in the Terms of Reference. Accordingly, h briefly describes (he back ground and objectives of the study in the first section followed by the description of the methods applied in carrying out the study Ins&rutions invoked in the development of imgaled tgn vulture and the policies set by the government concerning irrigation, are also pointed out Following thin. all previous studies found available are briefly reviewed, The detail description of the study area is grnen mcitulmg the location, topography, ctinule. water resources, land, and the I'wifr-cconomic conditions. Moat important of alL the potentials of the uea for irrigation development as a pre- hnunary identification together with the existing irrigation practices cuirrnth undertaken in the area are shown &. described in detail. The last pages of the report show the data gaps found and suggested means of filling these gaps, followed by (he general conclusion Jt recommendations given at last. The field vwt report and Tor is also annexed. .Muustry pf Wiles Etesorres Pdvrr Bsm Devdopmat: Siudies Department January 2000Aysha Dry Bum Miata Plan Project RcconiMiMarae Lmgitwn ft Drainage Repeat 2. Back Ground 2 In arid and icro-irid arras of the worid, where the annual rainfall is not sufficiently available agriculture can not be dependent on (he direct precipitation. Such areas suffering from shortage of rain fall have therefore been practicing the art of irrigation to make agriculture dependable and productive business. The world has witnessed the existence of tmgahon practice to have a long time history recorded since the beginning of civilization. It is however, a recent experience in Ethiopia which started around 1960 m a modem way M Larger scale level, although a few small scale traditional irrigation has been practiced some years before. Currently, not more than 190,000 ha of Land is ungaied in the country Which accounts Only about 4Qt of the total estimated potential ungable area of 3.5lo 4 million ha. The Aysha barin is the smallest of an other bason of (he country with estimated area of about 2,220 km3 The total basm area is characterized by low ramiall, high evaporation evapo- transptfahon. low or poor soil fertility and no or brtle surface water resource which makes irrigation difficult. In in area where agriculture is the only economic actjvirv and means of survival. Like the region in locus, and where rainfall. the most required input without which agnculiure can not succeed, is very scarce or totally unavailable ihraughool (he year, irrigation wiU be the only alternative tor development. On the other hand, water as the most important resource for applying irrigation, must be available at Any accessible ar obtainable location with regard to the land to be irrigated With this regard, the Aysha basin is however, not endowed with all the resources in question in order to apply irrigation for the agricultural activities earned out tn the area. Inhabitants of the basin arc* are entirely engaged in j pastoral life, rearing of cartie. Therefore, the land in this area is mainly to be used for the growing of pasture, although most of it is considered Ununhzable baiTm land. Mtrustty ofatet Rewrccs Rivet Rnn DevtJnpnbeni Studies Depanmeni January IconAysha Dry Buin Muter Pl*n Project Reeoanuuanee Irrigation A Drainage Report 3 In search of relevant informations and data related to any development of irrigation in the basin this study has earned out more or less sufficient investigations and collected as much data as possible Among the many developments constraints or reasons for being unable to utilize the resources Ethiopia possesses, lack of development master plan is the one to mentioned. The Ministry of Water Resources as a responsibled government body with this regard is mandated for the study and preparation of integrated development master plan for each river basins of the country. Most of these basin studies have been accomplished in the past few years and recently such a study for the dry basins is launched. The so named * dry basins ‘ is consisting of the three separate basins namely; Ogaden , Aysha and Danakil which are all located in the eastern areas of the country 3. Objectives As part of the dry basins integrated development master plan project, this study has its major objective of conducting a reconnaissance survey in the field of imgation & drainage in the Aysha basin. Of the intended three phase studies to be conducted consecutively, this study is the first phase study and is aimed at accomplishing the following tasks - To collect all existing information & data on previous studies and existing schemes regarding imgation development tn the basin • To conduct a physical observation at all accessible areas of the basin and assess the potential land & water resources with respect to irrigation development - To identify all potential sites suitable for irrigation in the basin including all alternative methods of water abstraction for each proposed schemes, based on the field assessment and map observation. 1 Ministry at Wiiet Resorccs Rd vet Bsin Development Studies Department Junaary 2000Aysha Dry Bam Muto PUn Project Rpakwwm toptaxi A Dnmig^Rg»rt 4. Study approach & Methodology 4 In accomplishing the study at this level, two major approaches, the field investigation and office level aueMment method* were used. Prior to the field viait, an office level aueument W*S carried out tn acarch of all avalable documents (Prwom Jtudict, rupk etc,} that arc relevant w lhe subject of our study. [n thn office level study, activities ruch as, collection of data A information from available studies of previous years, reviewing of these study documenta, investigation of potential sites from available wpo-mips of l 1:230.000, etc. sca e were thoroughly undertaken Under (ho circumstances, several governmental or non'govtnunenial offices at Addis Ababa that are expected to operate in the area in study or super vision of relevant projects, were contacted to obtain the required data and iniormancm.1. However, not much information was obtained except one brief note from one ot the nvrr basin studies conducted previously by WAPCOS of India, m 1990. After the office level assessment has been accomplished, the field assessment program was then launched to take a physical observation of the basin and collect first hand information A dju from relevant offices and local people in the area. In anucipstion to this field visit, questionnaires were prepared inorder to generate a|] required informations from the available sources Using these questionnaires and through other informal discussions, informations were gathered from various, responsiblcd regional office authorities and professionals. However, the field visit for direct physical observation of the basin was made only to areas that wort accessible. Ministry of Watt Jtesorcw River Bnn Ovdojmcnl Stmbei Department Jimuary 2000AviJu Pty Bwn Mute Ptei Project RK<gtfi*man« impBai A Primage R.epwt 6. Inatituttorval & Policy Aspects 5 A rclevinl Icgnlitinn no far, as regard* water resource utilizarion ill Ethiopia is issued in proclamation NO. 92'.94 The pmclxmaaon contains statement* concentring regional and central government responsibilities Dn water resources, which applies to all waler resources, ncf^c or undergr ound with the exception of mineral waters and geothe rmal deposits. It also demarcates (he responsibilities of the central and regional governments m administering water resources. The central government (the Ministry of Water Resources) u delegated as the appropriate body for the administration and management of all iransbcruitduy rivers and water that flows across Of lies bclWun more than one regjnnal government The regional Water Mines and Energy Bureaus, on the other hand, are respemstbie for administering the water resources existing within their respective regions including tributaries lo trans-regional riven. It b also indicated ths: utilization of trans-boundary riven shall be governed by inLemaiwtuJ treaties. L'hhzauon of tributaries of trans- reponal or tians-boundary rivers shall be dealt wuh specific directives to be issued by the c uuncil of ministers, According to the proclamation, a penrul issued by the appropriate authority (Ministry of Uater Resources or Regional government bureaus shall be required io use water resources for irrigation and oLhers. A penrut holder has to pay water fees and charges tor diLlerenl consumptive uses and his the obligation ol using the wner onfv lor the authorized purpose without causing hum lo the environment Likewise, the authority has the responsibilities of ensuring the water resources to be Utilized tn the most beneficial manner, supervising permit holders strictly to utilize the water tn conformity wLlh rhe condition of permil, collection of water charges and fees and settling of disputes arising between permit holders Regarding the Land issue the policy stales that both urban and rural land arc owned by the government and wiO be made available to investors on kasc-holding basis. frWrry of Water Rjvei Bun Devaopruan Studtea Deputrnml January M«1Ayiha Dry B*ui Marta Plan Project RecorauMsince lmgi&wi & Drainage Repwi________________ 6 Based on the size of land to be rmgated, irrigation schemes in Ethiopia arc classified into 3 groups, namely Large, medium A snull scale. Large Kale schemes include those ftoifi irrigated area exceeding JOOha, medium scale schemas include areas between 200 and 3 ha, and small Kale scheme* are chose below 200 ha Several national msCitutions (goviranenlaf & non-governmental) are undertaking the responsibilities of promoting the irrigation development activities m the country. The foUofting arc concerned inshnjnons invoked in the field of irrigation A drainage m the basin (among other responsibilities,) Central government I) Ministry of Water Resources Il li rtiponsiblc m different wjw resource studies and integrated development master pla preparation for die country's basins including irrigation development. ii> Water Worts Design <L Supervision Enterprise (WWDSE) Being under the MOWR, it is responsible for the design &. supervision of irrigation wherries tit the country. iii) Water Works Construction Enterprise (WWCE) Being under the Mirustn of Water Resources. it is responsible for the construction of large A medium scale irrigation schemes. iv'l Ministry of agriculture Through Its agricultural extension department, has limited mvoKetrwnl in small scale irrigation development promotion. vj Phmc Minister s office, desk ofihe Somali Region. It is invoked in the follow up of for lhe study. design and supervision of small migation projects, m support of the region'* development activities Stnrstry of Waler Restates River Him DewLopment Studies Department Jimuary loopAyita Dry Basra M-tngPlin Project RamnisMina Regional governments- A Drarnige Report 7 Through the following ippropriai bureaus regional government! tuve the respective powers and dunes m reUnon tn irrigation development t) Water. Mines it Energy Bureaus of die regional stale of the Somali This has lhe responsibilities of stud}, design and construction of smali scale irrigation schemes. □) Agricultural Bureau of lhe regional sutc of lhe Somali This has the responsibilities of supervising the operation and muncounce of the small scale irrigation projects constructed by other bodies, through their extension workm Other NGOs and private investors Although no private sector activity has been observed m the basin cuncnUy. any inicrestcd pnvatc investor can participate in lhe mvcstrneni or development of in^tcd sgnculrurc m the area. One NGO Lutheran U'orid Federation (LW) is titrrentb operating in the basin in the siudy, design & construction of small scale imgatian schemes. Ministry ofWatcr Rejoices River Bsm Devdopenent Srudies Department Junuary 3000Ayihi Dry Basta Miner Plan Project RcconniisMftre Irrigation A Drainage Report_________________ 3 6. Need for Development In spite of the significant or dominant role it plays in the economic sector to the country, agricultural production remains to be at a subsistence level. As in all other parts of the country, crop or livestock production in this basin is characterized by a highly rudimentary method or technique. The application of modem agricultural inputs like fertilizer, pesticide, improved seed, e.t.c., and the use of modem farm machinery i implements are not widely practiced Similarly, the rainfall in most part of the basin especially in the lower basin area, is inadequate in amount and erratic or irregular in distribution, and hence is largely unreliable. On the other hand, agriculture in the basin is mainly rainfed. For this and other reasons, the agricultural productivity of the area remains to be very low Such crop failures coupled with the high population growth rate (in other words, high food consumption) will further aggravate the food deficiency in the area or the country as a whole. Therefore, to avert such occurrences of food shortage and ensure sufficiency in food production, the promotion of the existing agricultural practices into an irrigated one, would be inevitable and highly recommendable. In addition to securing the food supply of the country, irrigated agriculture will also play an important role in the supply of products for local agro industries and the production of exportable items which will be earning the country’s foreign currency need. Irrigation development can also play an important role in the generation of employment opportunities and balanced regional development in neglected regional areas Ministry o( Water Rcsortes River Bun Development Studies Department Junuary 2000Aysha Dry Baai MirtaPtm Rrojwl Rpmninunft IntprtKxi A PTunagc Repcm___________________ 9 7, Description of the Study Area 7J. Location & Accessibility Aysha baain is located in the astern part of the country and entirely included in (he Somah regional state, Shurik zone. The bairn as delmcilcd on a lopo-map of scale r ii bounded between the geographic coordinates of 10’N to 1 Is 05'N bl I '250 000 ind 42" 15’E to 42*58 ‘E Long. The distinct boundaries of the basin arc Somalia in the cast, the Awash basin in the west JL south and Djibouti in the north. 'The basin boundary starts at around 123km north of Dire Dawa on the Dire Dawa-Aysha-Dewele mute, and extends north upto the Ethao-Djibouti border, Regarding accessibility, the basin is in a relatively better position compared to the size of the basin. An all- weather road of about 90 km and the Ethio~Djibun rail-way tine cross right through the muddle of the basin. Further more, there are also some dry weather roads and rough tracks crossing ostt the basin area in different directions. 7.2 Topography & land feature The Aysha basin coniiHs Largely of a plain rupography in the middle section and small scattered hills in the north and south-east areas. The northern part of the basin, which includes the area starting from some 20km north of Aysha upto the Ethio-Djibouti boundary, mostly consist of rocky i hilly land feature with undulating Topugraphi ranging between 800 i 1100 masl elevation. About more than 50km length between Biyo Kebobc ( a small tillage 135 km from Dire Dawaj and Adele f a small Rail way station 13-20 km from Aysha) tics ■ wide plum topographic land stretched widely left * right, The elevation, here ranges between 600 4 900 masl The southern pan consists of small scattered hills and a wide plain land of elevations ranging between 1000 and 1200 mail The land feature in general is characterized by a nearly flat tend on one part and some undulating land feature composing of various dry stream courses dissecting through on thr other pans Ministry of W«a Rewrote fewer Bmtl DeidopmcnL Stuia Departmcni January 20MAyth* Dry Bum Muter Plan Project Reconnu«an« Imguion ,fc Dninage Report 10 7.J Climate The Aysha basin is generally described to have a hoc arid to semi-desert climatic nature. Although any recent ar past records of meteorologic data arc not available, a rough estimation is given for someof its elements. Rainfall being monomodal (occunng once in the year) is generally very low with annual rainfall amount estimated to about less than 400 mm in most parts of the basin. Temperature is very high most of the year. Evaporation similarly is estimated to be high, more than 2500 mm per annum 7.4 Water Resource Reference could not be made 1o the hydrologic report of this recent study for it is not yet produced. Therefore, a short information from the previous study by WAPCOS and a map reading from a 1:250,000 scale topo-map is taken to tell about the water resource potential of the basin. According to informations from WAPCOS Study, the surface or ground water yield of the basin from the point of view of its contributian to the country's water resource potential is almost negligible. There is no any perennial river existing in the basin except a few traces of dry streams that come into life during the wet season. About 7 of such dry streams known by name are shown on the map This include, Kobe. Biye Gurgur, Gerbale. Lasarat, Seblola, Drlad and Debeder. among which the first two are the major ones Ail these dry streams mostly [low Along sandy river beds and terminate into the plain Sandy fields. The only water sources available for use in the community are these sandy stream beds. A shallow depth digging on these stream beds would produce water that fills the size of rhe dug hole. Perhaps this would be an indication that flow exist in these stream courses mostly underground in the dry season. Therefore, apart from the wet season surface flow occurring in these streams, the underground flow' should also be considered in the full exploitation of the resources available. Ministry of W«p- Rcwtcu Rjvcr Bun Devetapnnit 5tud»es Dtpuuncn! Juniurj 2000Ayah*. Dry Bum MuurPlui pTOjtct Rreoiuiumrice IrrigUiMi ft Dnuugr Report II 7.5 Aprie wfarre, Land Us e & Lend Cover Alm ost the whole area of the northern pan which covers nearly half of the total basi n is char acterized by a barre n sandy & rocky Land of rugg ed topog raphy, some scat tered h ills with almost no vegetation cover. The central part characterizes mainly of a sandy plain topographic land with very I tide or no vegetation cover, The southern part, however, is composed of some scattered hills and plain land of some scrubs, bushes and grass cover. The land in general as already in use (in the southern part) could only be used for grazing and probably for crop production (if waLer is made available) while the northern pan is unutilizable. Agriculture, although experiencing several limiting factors, is however the main economic activity of the study area. Of this activity, livestock development is the major one followed by small cultivation of crops. Only crops of drought resistant such as sorghum are grown in a few scattered small size plots. 7.6 So//5 According to the previous study carried out by WAPCOS. 1990, the soils of the study area are described into three groups of suitability level, marginally suitable, moderately suitable and permanently not suitable. Paru of the north, north-west, west east & south top areas are classified as N\ which is permanently not suitable with several physical Limitation for irrigation development. A small part of the central basin and southern areas are classified as S 1( moderately suitable with some limitation which slightly reduces productivity, medium to fine textured, slope 0-8%, elTcctive soil cover of 100-150 cm, nunc to slightly salinity & alkalinity and moderate to well drained. The north-east area is on the other hand classified as S. marginally suitable with moderate to severe limitation which reduce productivity, fine or coarse textured, slope 0-8%, effective soil cover of 50-100 cm, none to moderate salinity & alkalinity and impeded drainage. Ministry of*ner kewccM Rjvct Bun Development Studwj [kpanrneni Junuary 2000Ayrin Dry Biam Metter Flip Project ReconiMisMia 7.7 Soc/o- Economic Aspects & Urtiraage Report 12 The Aysha basin is totally included in the Somali regional state of the Shinele zone. The area is entirely occupied by the Somali ethnic group. The papulation coverVdistributton^ is generally very low with estimated papulation density of not more than 20 persons per knf area The economic condition of the area can he over-viewed as generally poor, with Idw economic resource, low income, high shortage of food, etc. The major economic activity is agriculture to which the whole population is engaged Inhabitants of the area are living a nomadic pastoral life and arc engaged mainly in livestock herding Cultivation of crops is also rarely practiced. Infrastructural development and public services such as education, health, communication, water supply arc generally poor although possessmg a better road &. railway facility compared to other basin. Urban development is almost non-existent except a small sign in the small towns or rather villages of Aysha and De welt Only a few organizations like Lutheran World Federation are involved in very few development activities such as in community water supply and small scale irrigation development. EL Existing Irrigation development practices Except one or two small scale irrigation, there is no significant attempt made to promote irrigation development activities in the basin, despite the fact that successful development ■n agriculture could not come true without 1 rrigation. The Lutheran World Federation, a non-governmental organization, has designed two small scale irrigation schemes at Blvd Kebobe and Semcka which are -currently under construction. Ministry of Water Rentes Rj«r Bsui Development Studies [Jcpinnitnt Junuwy 2OMAjihi Dr/ Bisin Muter Plm Project RpcwimissiMC Lrrigihoti & Draining Bepcn ]J The project it Biyo Kebobc consists of a sub-surface dun across Kobe stream and diverted for irrigating an area of abt 50 ha land downstream The Semcka scheme on the other hand is designed to irrigate about 40ba land by diversion. Apart from these two small scale schemes, a few traditional irrigation practices arc reported to exist in few localities. 9. Potentials for Irrigation Development Investigation of potential arras for the development of irrigated agriculture, has been the major objective of this study as indicated earlier. Accordingly, all possible investigations from the available topa-maps of scale ! 250.OW, primarily for the availability of the required resources, arc thoroughly undertaken. Land & water which are the primary and most required resources for irrigation development arc, however, not appropriately available. Topographically plain and suitable land for irrigation may be available where as none of these areas are endowed with the water resource. Bui the availability of land alone without water cannot be considered a potential irrigation area Therefore, the basin as a whole is identified to be a low-potential area for irrigation development However, the need for the use of irrigation in crop production Dr even in pasture development in the area is very well noticed. To make ihe area self-sufficient in food production and earn extra income, the agricultural sector of the economy which is for the moment the only feasible alternative, should be promoted. And it is only with irrigation that sustainable development can be achieved m agriculture in such arid regions. Laige or medium scale development in irrigation is unthinkable However, small scale irrigation schemes can be introduced in some selected areas, with the use of the available run water as source of irrigation water. Ministry of Water SworcM River Biui Development Srudi« Depmmcnt Junuary 2W0Ayihi Dry B*sin Muter Plan Project Recmntiuanee liriguuxi A Drainigc Report 14 Different rain water harvesting techniques can be applied inorder to avoid the existing water shortage problems. It increases the amount of water that can be available from the only available source, the rainfall, and satisfies the crop water requirement of the selected cropping land. With this regard, the following techniques may be suggested. - Run off farming:- This is a system of fanning in arid areas, where that portion of rhe rain water Converted into surface runoff is harvested from the sloping uncropped field in the upland of larger area, and made to flow and stored into the soils of the relatively smaller area of the cropping land below. The runoff water is lo be collected and directed to lhe cropping land using bunds and channels provided in the system or through natural wadis. - Micro earth dams:* Small earth dams can be built at appropriate storage sites to trap and store the small rainy season flow m the wadis and make use of it for irrigating the down scream selected land. Thr Appropriate sites for applying the above water harvesting methods as small scale irrigation practice, would each be identified in detail in lhe second phase study. The following 3 sites are indentified as potentially imgable areas, From these sites about 4300 ha. of land is estimated to be topographically suitable for irrigation if adequate water is to be supplied from the corresponding streams. However, since (he flow amount of each stream is not known or availability of water is never expected reliable, the irrigable area estimation should not be taken as a potential figure. It is only the topographically suitable area that can be commanded from th identified diversion sites. In any way these streams may only be capabl e of serving t supplying} small scale irrigation schemes. Ministry of w*ux Rcsonxs River Bun Developmctu Suidits Department Jimowy 2000Ay^ha Dry Bum Master Plan Project Rttgnmkisince lfiig.Bb&n & Driiiugc Report_____________________ 15 Possible areas of email teals irrigation development Sites f. Irrigation from Kobe stream The Kobe "shef' (stream) is a seasonal stream which appears as a surface flow only in the wet season of the year but exists as a subsurface flow under its sandy stream bed, It originates from the small hills of the southern basin border at elevation 1300 mask and flows north-ward across a wide plain land , crossing the Dirr Dawa- Aysha road near ihc village of Biyo Kobe ana ending up into a sandy plain area around elevation 80Q m a,s i A diversion at elevation 1050 majj. would have a potential of irrigating about 1300 ha. of plain land down stream on both sides of the banks As an alternative, a dam site (mosdy of a sub-surface dam) may be proposed down stream at elevation 950 m.a s,1 near Biyo Kobe to store both surface & sub-surface flow and make available a dependable water source for irrigating the down stream field covering an area of about 3200 ha. Bui currently construction of a diversion scheme is undergoing for the purpose of irrigating 50 ha- of land 2. Irrigation from filye Gurgur Biye Curgur "shef is a small stream originating from a similar (very near) area where Kobe originates and flows north ward parallel to Kobe crossing a large plain area which finally ends into the Ethic-Somali border. The stream may be diverted at elevation 950 mast near Biye Gurgur village to irrigate an area of about 2700 ha downstram on the right bank Of the stream. Miniwry of Witer Renvcn Rjvcr Buti Deveicpoicni Studies Dtpai-tmer.i Junuarx 2000Ayiha Dry Baam Matter Plan ReccmnatMance kngatwn A Dtamage Report 16 1 frwn the otfwstnams The other dry streams ahown On (he topomap, namely; Gerbale. Laswat, Scblda, Dclad and Debcdcr are aO small in size and flow across the unsuitable soil areas and thus no lrtgaijon is expected from them. Only (rerbals may however be able to irrigate an area of about 300 ha if airuO to medium storage dam is to be bail I 10. Previous studies Reviewed Except one study document prepared by WAPCOS { W'atCT and Power Consultancy Sendees) of India, 1990. no other document was found available for review In this study onh a very brief uiformadon in not more than one page, is shown about (he general situation of the basin. The source document entitled as “A Preliminary Water Resource Development Master Plan for Ethiopia " Vd -D Main Report by WAPCOS & EVDSA, 1990, produced a study report, combining the three basins (Ogadcn, Aysha &. Dinakil ) in one report as Eastern Basins’, This report briefly describes the Aysha basin as an arid area with an almost negligible water resource or irrigation potential The study generally lacks sufbc lent data 4 information and detail descriptions about the basm. thus not reliable. Ministry of Utter R&ar«r Rive Ban Development Sfuzhci Dcpurmml Junuary TQMAyitu, Dry Bwi Mistc Plan Project Rewmjiiuwm foigibon & Druiugc Report 11. Data Gap* of the Study P As indicated earlier, one of the major objectives of this study is the coUectkffl of data from the study area. It is evident that these data are not sufficitnlhr obtained as required, and hence dau gaps were made in the overall study result. This is because the field visit was not carried out as intended A planned and first hand information could not be gathered right from some pans of the basin area, Secondly, the data obtained or expected to be obtained from the regional offices and existing study docimienw were not satisfactory oner. Therefore, it h. inevitable that gaps could be made m th: data collection of this study. Th cm include: , IjcL of topographic maps of the bwm areal Scale 1. 50,000) These maps were very essentia] for detail investigation and extraction of more dependable dau on the basins physical fcarures. More over, better identificahon of sites for recommended micro earth dams or other ram water harvesting, could be made al least with such large scale maps. Although these 1: 50.000 scale mips air not still appropriate for tdentification of small scale development silcs. they gvc at least a better view of (he area. As a means of filling (his data gap. a request has to be made to th: National Mapping .Agency of the making of the required scale maps of (he basin Since they arc noL available al the rnomcnL. - Lack of a full field observation dau Since the field observation (a field visit m the basin j has not been fully- earned out due io its inaccessibility and security problems, the required field data were not collected sufficiently Thu gap shall be filled in the next phase study when accessibility is unproved and security continued. An aerial field visit (with a helicopter flight) can be made if accessibility will remain a constraint Mimsm of Vi i'.tr Resects Rjver Bsm Development Studies Department Jieidao, 2000Ayiai Dry Burn Muter Plan Project Rjmmmujmbcc [rnjBbDn J: bfttfiage Report l« - Incompletion of data gathering & compilation from re lated study sectors. Data that arc relevant to the irrigation A drainage study, but which are to be obtained from other study sectors, such as data on soil suitability (from soil study), water availability & quality (from hydrology), crop suitability (from agriculture) etc. are not yet collected. These will be collected and reviewed in relation io imgation & drainage aspects, in lhe next phase study. Xiinirtrs of Water Rewrtes Riw Bsm Development Studies Dqpmmcni January 2000Aysha Dry Baatn MtW FUn Pittas Kaacwuna! ImgWMn it Dmaagc Repel ______________ ______1? Conclusion & Recommendation The study rtmltj shown above fntil that the whole binn area is in great shortage of water resource*. Thu water shortage problem coupled with the severe climatic condition of the area, has nude tmgaled agriculture somewhat difficuh. However, the avidahiEity of such vast A topographically suruhle land could be utilized for cultivation of crops and pasture if every effort is ma/te to make use of the available water for irrigating it m any possible technique. According to rhe estimated climatic information of the basin, rainfall amount is very small, not exceeding 400mm at average, and even worse than this in the far northern parts which is fess Dun 200 mm. This amouni occurring in an erratic distribution pancm, is never to fulfill the evapotranspiration demand of arty crop mtended to be grown in the area. The potential evapotranspiration of the area, estimated to be more chan 2500 mm perannum, is much more than the annual rainfall amount. The only means of converting this small amount of rainfall mio a useful resource, into something that could be sufficient for growing crops, i» by applying a rain water hamcstir-c; technique In doing so, the amount of waler collected from in area will be made to flow concentratedh. over a muller area of crop land end stored in the soil profile to be used by the crop until the next flood comes. In general- the studs has come up with a conclusion that the total basin area is identified to be a low-potential imgaocm Mi in large or medium tcalr Level due to mainly of waler constraint. Except two or three dry streams, no signdlcanr stream flow has been identified. Probably some wadis met dry sandy streams, where underground (subsurface) flow occur, could exist in many parts of the basin. A short period surface flow in the wadis may be observed onh jn the wet season while the nibsurface flaw may stay until the dry season period. Therefore, the sctefcace of such areas could be accounted for the suitability of spate lmgation or nm off farming system, and reservoir irrigation using mivrotarth dams and sub-surface dams Ministry eftin Aworzes River Bsm Development Studies Departs™ Junuary JDOCAyrhi Dry Birin MtncrPIxn Project ReccnuB usance IrrigJboASt Draurigc Report 10 A? a coneJusiOFK UlC basin." 5 potential far irrigation development is limited Cd Otlly small scale lever. where the source of Wafer would be made available from either; i) Diversion pf spate flow in the wadis Or Other ram water harvesting lechniqaa. Lt) Construe non of small storage earth dams on exiiting dry scream courses for intercepting and storing the wet season surface flow. iH) Construction of small sub-surface dams for intercepting and Storing the sub- surface water flow in the sandy stream beds. n) Ccnsiruction of welts for extracting the ground water resource. It is therefore recommended that tbc above water development techniques be applied inonfcr 10 ttuike the required vrarer available for the intended small scale irrigation Schemes. Investigation of suitable areas from larger Scale maps, such as 1:50,000 should however be undertaken in the next phase study. Since rhe overall population Of Che area is largely bound CO a nomadic pastoral life and lhe land is mainly suited for or classified as pasture land, development in this field will he gLven rhe priority, Therefore posture land imgauon using the above mentioned water harvesting techniques can be practiced for improving the range land condition of the area, fi had earlier been described that adequate field visits have not been earned out due to problems of security i accessibility. Therefore, serious attention must he paid to 3 reconsideration of a field visit program using vehicles or helicopter in all important and possible visiting silts of the basin for better observation AJlii data collection. Ministry dC Witti Robert River Bun Devtiopmcm Spudiei DtpuUncnt Juniurv 2000Aysha Dry Basin Master Plan Prqjeti Rccohm usance Irriganon & PnmAge 21 Field Trip Report f- /ntroductton LI General To properly develop and utilize a country’s resources, development master plan is very essential In this regard, the Ministry of Water Resources, given the responsibility of studying and preparing master plans for the country’s river basins, has been doing its best on the preparation of integrated deveopment master plan for many of the river basins. Similar program has been launched recently for the Aysha basin. Since the master plan preparation is intended to be accomplished in three phase studies, the first phase or the reconnaissance level study is one of these phase studies which this field trip is committed to. This report deals with the irrigation & drainage aspect of the basin considered as one study sector among the many others in the program. The report will briefly show the overall activities conducted, local areas visited, institutions and individuals contacted, etc while staying ai field. The field tnp was carried out from 18 June J 999 to 28 July. 1999 which totally took about 20 days. This field program generally covered only (hose visiting sites that are accessible by vehicle. Since one of lhe objectives of the field visit is to colleci required data from the main data sources ie the regions, alt the regional. & zonal offices which are included in the basin we visited Likewise, existing rivers of the basin and their adjacent land are visited wherever accessible. The tnp was conducted in group consisting of four members of different professions Ministry of Water Reserces River Bain Devetopmcfit Studies Department Junutry 2000Ayshi Dry Buin MmcrPlui Project RecotMumancc im^ilion A Dramgt Rcpon_______________________ 1.3 Group member The group members participated in the field trip consist of the following staff of rhe project |. Wubishct Alemaychu 2- Beta* Tcgegne 3 Abinct G/Mcdhin J EyiJachew Yitiyew Purpose of the trip Irrigation & drainage Engineer Dann of Hydro power Engineer Gco-technical Engineer and infrastructure Emgineer Geologist 1.3 As a partial fulfilment of the terms of reference prepared for the irrigation & drainage sec Lor of this reconnaissance study, the purpose of this trip was in general to conduct a preliminary visit to all accessible pans of the basin. The particular purposes include.- - Visiting and collecting mfoHnaiions from all regional and ional offices found in the basin, regarding all existing studies and project activities tn (he area of irrigation and drainage - Taking a general view of the baSui through physical observation of the resources available. - Identifying potential sues for irrigation & drainage projects in the basin and justify the map identification for the proper location of both diversion dam sites on the rivers (water sources) and adjacent tmgablc land. Ministry of Ww Rciorm RwW Bsin Dtvelopme™ Smdtes Dqsrahent Jumiary 2000Ayih* Dry &wui frUutJ Plan Pfrojcsi 2. Actlvitia a co nd u ctsd Imgmipn A. Plunge Report _______ 23 Being arranged as a recannaLssancr visit to afl accessible pans of the study area, the field trip has come up with (be accompfishrticnt of several important activities- The major activities of the trip may briefly bt described as follows. - Visiting of govemmcnl offices involved in (he field of irrigation & drainage works in the basin. The regional and zonal offices were visited and discussion held with concerned officials inorder to obtain required dau and mfonnaiJons on existing irrigation schemes and newly proposed or ongoing project studies within the basin. - Assessment of other nongovernmental and private organizations which arc involved in th? Study and construction of irrigation schemes al regional &. zonal levels. - Conducting of discussions with indjvdua] fanners involved in irrigation activities. ■ Physical assessment of all accessible irrigation potential sits that have earlier been identified from the available topographic maps of scale 1 rSG.OOO and 1.250.000 In the overall reconnaissance visit which have been found accessible. only a small poniofi of the total basin area have been visited. The major travel route include the following I) Addis Abeba - JijLga u.) JijLga- Diredawa iii} Dire Ditwa - Aysha' Dew tie. MlhiSV? of Water Ptejocrei Rjver Bim Dev?lqprncm Studies DepJ^mcnr Junuary 2000Ays>i* Dry Bu-in MasarPlan Project Rccaunimnu Imgation A Dnunge Report 24 2 P1 Visited Government Offices V Officer Region Zone Fewft 1 Water. Mines & Energy bureau Somali - Jijiga 2 SERF ria kt, * 3 Agricultural Bureau « * M- 4 ■Is -M Irli Shin He Dire Dawa 5 ESRDF flit - Jijiga Among these offices, only the Water, Mines & Energy Bureau of ihc Somali region is found responsible for irrigation works but so far has done nothing in this basin. 2,2 NGOs Contacted Among several NGOs operating in the basin, only a few are involved in irrigation activities. The following offices were contacted during ihe field trip for search of relevant data & informations. Offices Zone Zoivn 1 OXFAM | Somali - Jijiga 2 Save the Children Fund L'k-iSCF} - BL 3 Lutheran World Federation (LWT) 1 Diredawa Dire Dawa 4 EHDA [ Somali Jijiga 2.3 Private organiiations No private organization involved in itngation activity has been found in the area 3. Visited sites At) Sire Ae;ion Zone 1 Elbayc Somali Jijiga 2 Biyo Kobobe stream ■is Jijiga Shinile Aysha 3 Aysha ■1* ** ■IS 4 Dewele W fl Dcwele Miruray □( Waicr R«ort« JLver Bun Dcvdopme,,, 5mdlc. Dep*rtm7^ Junuar. 2000Ayiha Dry Bmiti Miner PSan Prajtti HttanntniancE Imganafl A Drauuge Ke pen < Gov*mm*nt Officia Fa Conte cted 25 F Place ,Vjaw Official Post Office 1 Jljiga Giday Irrigation Team leader Water Mines & Energy 2 ■M- 1 Siyoum Agronomist Agriculcural Bureau 3 Mohammed Project officer IESRDF 4 Hi - Project Coordinator OXFAM 5 ■Li - u. -fca SCF 6 DirrDawa Hli^ls Mohamed Head of Zones Office Agriculture Bureau 7 fail Yideg Af ta Coordinator LWF.Diredawa 8 H Awlachcw Abe be Technical Section head ■i iU S 4 Prt>b[em> Encountered Although The field program has been completed as scheduled, problems of different sorts were however encountered m the course of the trip. Some of these are as shown below. - Accessibility is generally poor for mosT of the basin area. Because the field visit was earned out in the wet season of the year, fivers were filled and roads & bn dyes were over flooded at some places. This has made some of the accessible sites difficult to cross or sometimes caused delayancc in the travel program. Other proposed sites to be visited (idenufied from, topo-maps, especially those located in (he eastern low- lands) are totally inaccessible due to either lack of roads or climatic problems. There fore it was not possible to have a visit to these areas. Concerned officials or other resourceful individuals to be contacted for obtaining ihe required informations, would sometimes be not available at their offices during our visit. V^e had to waste some time for waning or otherwise compelled to contact some other persons who have a lesser knowledge of the information we require. - Topographic maps of reeie 1:50.000 which ere more apprepnote for idemific3t,on of.mgauon command areas were not adequately available for the whole basin area. qf R™« River Finn Dcvelopmem Studio Junvary 2000Aydia Pty Basin Mmtf Plm Project bngitrcm & Dnuuge Report 2ft - Some minor problems such as vehicle maintenance, defective roads. etc have caused some delayance in our daily travel program. - Group members combination was not appropriate. For instance the hydrologist and hydrogcologist should have been assigned with us (the water resource group) because it could have been very convenient to exchange ideas and discuss matters in site identification work Mmusy cfWto IL«r Biln Lfcvclopn^t J'unu&ry 2MoAyilu Dry- Basin Muts Ptan Project Rwxmmuumucc Irrigation A Drainage Report _ B, Conclusion A Recommendations _ 27 Every possible attempts have been made to cover the proposed activities of the field trip which was limited to only accessible areas of the basin. As much information as possible have been collected from contented offices and field investigations carried out from al! accessible sites in accordance with the terms of reference However, the area coverage of the field trip was not targe enough to be able to show the full view of the biun. Only ihc areas along the Ihredawa Dewcla rood were visited while other proposed sites could not be visited due to accessibility problem. Therefore, to conduct a complete investigation. to the basin, the following may be recommended. - A helicopter tour program shaD be arranged to visit those inaccessible areas of the basin. ' Topographic maps shall be made available through the Ethiopian Mapping Agency * Group members discussion shall be made especially among those related snidy disciplines Muimry of Water Rewrea River Bi!T. Develops Smd.es Depamneni JtinLmjy 20Q0Aysha Dry Bum Miain Plan Project Reconrumtnce imga&an A Drimage Report Annri H Term* of Reference for the Reconnnuance Phase study of the Dry B**in Integrated Development Master plan Study FroJ«X /AA/G4r/<?5*/tVD D«4ZM(7£ I All existing studies within the basin tn the arte of irrigation and drainage and relevant sectors wiD be coDccted and reviewed. 28 2. A reconnaissance vi«i to all accessible pans of project sites will be done for a first hand information 3. For the identified irrigation and drainage projects, water resources availability, climatic conditions, soil suitability, population dcnsiiy, food deficit, location accessibility etc. will be examined in consultation with the other experts. 4. u"herc major storage is required for imgarjon development, the location of this will be indicated to the relevant expert for the wlccUon of appropriate dam site. 5 The dala gap for the iTVdy will be identified, and means of filling the data will be suggested. 6. Wtwi program for the second stage of the study wifl be prepared. 7. .All logistic, laboratory requirement and other relevant materials requirement for the sector will be identified for the secund stage of the study and presented. 8 with all the above informanon a rcconnaisMtice report wifi be prepared and submitted. The work program tor each activity is given tn the overall activity program of this study and submission of the ourpui will be lti line with this work program 10, Preliminary identification of potential irrigation sites if possible. MrnHiy ofWnsr Resaos Rjv« pjJin Devetcipmmt Studies Department’ Junuvy IMOAy$tu Dry Ekm Muter PUn ProjcdJlcccmMMMKC Emgmon * Draange Report Annex » Terms Of Rrftrnure for the RkoOhAiMUC* Phase study of the Dry Basin Integntrd Development Waste r plan Study Frojen. IRJUGA T/QN AND DRAINA GE 1, All existing studies within the basin in the area of rmgatiCKL and drainage and relevant Sector'S will fee colkitcd and reviewed. 2. A recGnrui&antt visii io all accessible pins of project ata will be done far a lirst hand information. 3 For the identified imgahnn and drainage projects, waler resources availability, climatic caididoni soil suitability. population density, food defkik loc-atwm accessibility etc. will be rtimmed in consultation udlb th: other experts 4. U"herr major storage is required for irrigation development, the location of this will be indicated t<] the relevant expert for lhe seteetjan ot appropriate dam lite. 5. The data gap for '-hr study will b<; identified, and means of tilling the data will be suggested 6. Wort. program for the Second Stage of lhe study will be prepared. 7. AH lo^shc, hbcmJon requirement and other ndevxnt materials requirement for lhe Mdor Wifl be identified far lhe Second stage of iht study and pfCJmicCL 8. With all the above information a recunnaissance report will be prepared and submitted. v The work program fcr each activity is given m the mill activity psogjarr. of this study and fUbmtMlon Ot lhe nutpui mil] be in line with this work program 10. Preliminary identification of pmcnUal irrigation sites if possible. Mnusrry ofWlffll Rrtowcs River Bun SuvrJnpnuiT.i Studies Depanmou Jimuary 2000Aysha Dry Bum Uma Plan Project R wwuuman« imganon A Drumy Repart 29 Annex Til THE DRY BASIN INTEGRATED DEVELOPMENT MASTER PLAN STIT^ PROJECT TERMS OF REFERENCE FOR PHASE II AND HI STUDIES Irvif aftOK a/td Dramagt 1 All data, information & maps relevant Co the field of irrigatjon &. drainage study shall be collected, analyzed and existing studies reviewed as to recent information i maps available 2, .All potential areas of irrigation development shall be identified (including those obtained from che reconnaissance study) on the basis of suitability of topography, sods, water, c.tc and availability of sufficient waler quantity 3 The need for major storage dams shaD be assessed and indicated to the relevant expert for selection of proper dam sites serving the respective irrigation sites. 4 Field visits ( with helicopter i vehicles) have to be carried out on selected irrigation sites for further close investigation. 5. .AD sources of tmganon water (surface & ground water) and means of abstraction shall be assessed and identified for all proposed irrigation schemes .All engineering options shall be compared co select the most appropriate head work Inter basin or basin transfer of water sources mio potential irrigable land, where ti»crc is shortage of water, shall be considered. 6. Collected data 4 information available from relevant study sectors like soils. hydrology. agronomy, socioeconomy , environment etc. as analyzed by each sector shall be examined tn relation to the proposed irrigation sites. 7 The lota! project water requirements ( net Gros and peak season demands) of each scheme must be estimated calculated and compared with the available water quantify of each identified source, in order TO determine the size of the maximum imgabk area This may include. - Estimation of irrigation efficiency, water iossesdue to evaporation dfc transpiration (evapo-transptranon demand), additional supply from effective rainfall, other water demands like leaching, etc. ■ Compulation of crop water requirement of possible cropping pattern and cropping intensity. 8 After comparing all convmuonal systems of irrigation (gravuahorui, pressurized) to be applied for each proposed scheme, appropriate trrigauon system shall be selected 9 (■ rom selected potential areas, projects snail be prioritized according to prioritization criteria for pre-feasibtliry studies The selection cniena shall be stated bv the consultant and will be approved by the client. Iiraivr-Bn rifuV>The prefcaiibiljty xtudiu contain, 10 Layouta and preliminary designs of the rfrigatiun systems (at scale of 1 20,000), canals Mid other hvdraultc structures have In be carried out for cachsclcctcd sites of lhe pre-feasibility level study. Ah alternative datigtw shill be presented alongside with the most Kcndmical proposals. Typical sample blocks and irrigation A drainage structures shall be made. 11. Surveying of sample areas al scale of 1: 5,000 has to be carried out consultation with the responsible experts on the proposed irrigable Lands. AD required maps (topographic and canal sections) shall be prepared si required scales with one meter contour interval and detail design of sample blocks shall be carried out. 12. For all prioritized and selected irrigation sites, preliminary costing shall be made including for ill engineering works of the diversion weirs. off-takes, canals & drainage works and olhcT infrastructures, m order to csUmalc the cost of the whole project, Plus may include - estimanon of development «w ( costing of tertiary units) - estimation of major irrigation 4 drainage canals associated with major structures. - Estimation of abstraction systems ( head-works like dam for multi- purpose or trngation development, diverrion wnr and pump stations) - estimation of total project cost. 13. problems of drainage, flooding, uiuuty or others shall be identified wherever is existing or expected to occur in the course of operation of imgarj'3Tl projects, and thus proper solutions such h: ippropnaie drainage designs, flood protection works, land reclamation & soil management practices shall be proposed. 14 Plan of development scenarios has to be prepared with a guide fane for water allocation for normal conditions and extreme years. 15. Studies regarding small scale irrigation development projects shall be conduct with the following pomts of emphuu. - Inventory of existing studies, constructed schemes or those under construction regarding small scale irrigation projects shaD be identified using L50.000 tcalc topo-nups and aerial photographs - Each small scale irrigation sites shall be visually inspected as far as possible - Design and cosung of proposed schemes shah be earned out. S,Udy " ulccP'30n Progress report, ir+i-i .if "VlFwi'da- Q wru-rifcj £i r’-Rh.in. 1fW|AyiJw Dry Bmn Muter Plan Project RgEcmnaissaJiw ItpgtDon ,*■ Dramtgf Repon ?J Reference* 1. APS i NRDEP, 1995 Tern Depressian ReCOArtUSWCC Study, Final Report. Addis Abeba 2. CO- SAL RAR 1998 Irrigation Projecl Study for the Afar Reg. Sute, Executive Summary. Bahrr Dar. 3. CO-SAE.RAR & CECE. Kobo-Girana Valley Development Program Feasibility Study Report, Vol IV. Minerals, energy and water Resource Assessment, Final report. Addis Abeba. 4. FAO, 1995. Irrigation tn Africa in Figures Water Report'* Rome. 5. IPS* 1999! Resource Potential Study for Industrial Development in the Afar National Regional State, Vol IV', Minerals, Energy *nd Water Resource ssessmcnl, Final Report, Addis Abeba. 6. IPS A the Afar Desk of (he prime Ministers Ofijoe of the Social* Administrative &. Regional Affairs Sector, 1998. Technical Proposal for the Feasibility Study of an integrated Development of the Tetu .Area in the Afar N ational Regional Slate. Addis Abeba 7. REST, 1998. Fcasihilin- Study Report for the Raya Valley Agricultural Development Project, Vol H, Water Resources Aruiw-D Inigation Development. Plan 8. WAPCOS EVDSA. 1990. A Preliminary Water Resource Development Master for Ethiopia, Vol-Ct Main Report, The Eastern Basins. Addis Abeba* M^try of Water Rew™
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