9.05/02 
Developmeni                  Agricultural        Valleys ectoiAAtA            Provisional          Military Ethiopia            Socialist of 
Authority 
Background 
DEVELOPMENT 
Govemment 
DABOUS 
for 
Paper 
a 
Feasibility                IRRIGATI 
and 
General CN 
PRaJECT Study 
Specifi 
cations 
PROJECT  IRRIGATED 
AGRICULTURE 
OF 
February    1980 
Food 
and 
of Agriculture 
United Natlons 
Organization 
the 
United 
Pro 
evelopment Sh      3B 
fAT 
Pnunal  Mitary  Ciuvernmen Soxialist  Ethiopiu 
Inlted  Satius Ivelupmen 
Prugrunn 
IA 
A 
Valleys  4grleultural Development 
Auihoriy 
AN 
tood   and  Arrleulttes of  the 
aniatlon 
CsENIATIO 
DEVELOPMENT  OF  IRRIGATED  AGRICULTURE 
PROJECT 
Background  Paper and  General Speoifications 
for a  Peasibility Study 
DABOUS   IRRIGATTIN PROJECT 
.05/02 
February  1980 Putina
1   -r Introduction
De    opens nt of Irrigated AgrLCUituia m Ethiopia
2   - The Daboua Project
2.1    1 Developnant to Date in Western Region
2.2    5 The Area to bo Developed
2.3    j Tte Suggested Development Programme
2.31    Status of Studies
2.32    Ths Identified Project
3  - Cfajactive of Requested'Study and Major Orientations
3.1    : Objective of Study — Lavel of Study
- Integrated Programme for Rainfad and Irrigated Agriculture
3« 2  : Major Orient at ions - General Specifications1, Tirt reduction
1,1    iftu Objectives of Dove low nt
The t<rt*l population of Ethiopia io about 28 millions (about 90^ nurai) and is growing at bcm 2.?£ annually. The great majority of the rural population livea in the centre of the country in the high plateau areas ever
1 500 «T altitude. The extanaive lowlandB which surround tho plateau are inhabited mainly by nomad io pastoralists*
Total gross dorostic product (GDP) for 1974/75 iH estimated at 5 103 Billion Birr or 188 Birr per oapita* Per the period 1969/70 to 1974/75 at constant prices the growth rate was estimated to be 2*7$ par annum*
Agriculture generates some 50$ of and provides a livelihood for
over 80$ of the population* In recent years, crop production has accounted for some ?C$ of agricultural production, and agriculture (including livestock products) has aooounted for about 90$ of exports. Moat of the production is from the highland areas, but the pressure of human population is leading to increasing degradation of soil fertility and Boil erosion* In the highlandr, the average farmed area per family ie email (about 1*3 ha cropped land) ondL methods of cultivation have remained unchanged for centuries.
The present situation of agricultural sector may be aummariied with the following 1976/77 figures 1
Agricultural Area 1    annual drops
5 650 thousand ha.
psrttiajiftnt crops
451
II
11
fallow land (included
in private holding)
943
II
11
pastoral land (inoluded
in private holding)
628
11
it
other land (included
in privit® holding)
274 '
n
it
TOTAL
____
11
if
LivBBtcdc 1 oattls
27 211
000 aniMla
■hBBp
8 441
000 «
govtB
7 846  000       "off
2
Agricultural production (mjor crops)
(in 000 Ha)
1 553.6
arley
(heat
(aiaa
iorghuro-ailet
3il seeds
849.2
551.7
700.9
1 018,0
176.1
fie Ida
(T/Ha)
0,720
1,120
1.070
1.450
1.170
0.270
Production
(in 000 T)
1 121.4
947,7
592.1
1 051.3
1 166.5
47.2
Pulses
691,2
0,920                           633.9
Other annual crops
72.0
Cotten
33.2
2.100                             70.9
Coffee
400.0
0.500                           200.0
Sugar-cane
10,1
106.500                        1 081.3
The coabination of  increasing population pressure and m      ir»liable rain- fall causing a aerie* of orcp failures in recent years led to widespread
dintrees and fsatne in local areas. This situation tea necessitated aa
increase in inport of food grains, whioh exceeded 300 000 tone in 1978* Sitport' of cultural proluoo have baua traditionally based M coffee, oilEoedB and pulaea« Coffee output have been significantly reduced recently duo to widespread outbreaks of coffee berry disease. Exports of pulses and oilsoadn have decreased, both in absolute level and in proportion of agri cultural erpartn# Imports of cotton have been falling, and should becooe exports when new cotton projects cone into production In about five yoaro time. Ethiopia han a high livestock population, but production no th ode are aimed more at maintaining the saxinun numbers rather th"' '-anarcial production of ■sat or other livestock products, hoc the a eat or in almost entirely traditional,
1.2 DBvrloprsBnt of Irrigated Agri culture
It ib against this background that interest in irrigation has developed, It in ostisated that there is at presnnt 80 000 ha developed for
irrigation in Ethiopia i
Awash Valley
Xarah Out
55 600 ha
10 000 ha
Lower Onah
1 000 ha
Teaaenay
10 000 h*
W*be Shaballa
3 800 h*3
However, at least 20 000 ha would require full rehebilitati® art •
^uonahle estimate of net area under irrigation is oom 60 000 ha* Over JOjt of this Ilea in the Awash Valley and is planted principally *lth sugar 3&ne  ootton and maize. About 16^ in the Mereb Gash Basin, planted to
f
salee and ootton* About 7% lies in the Rift Valley lakes area growing
ootton and nails and a snail area of tobaooo) and there is a further 6^
planted mainly to maiae and sorghum in the Habe Shebelle area*
Account   be^rg   taken   of   the   various   faotore   affecting   agricultural prod notion f  the economic future of Ethiopia must be based on two major considerations i
-    the urgent modernisatian and intensification of traditional agri culture (mainly in the highlands area) through the introduction of Improved farming systems and practices, including the litre- duotion of appropriate reafforestation, soil and water odBServation measures |
-    the development of the vast potential existing in tbs valleys of Ethiopia by opening up naw areas for modem and efficient irrigated agriculture*
1
Currently, Government  s principal objectives for agriculture can bo suraariaed in general terras as !
a)    increased food production. particularly in dalicit arciui, aiming initially at           If—rufflatency in food grains;
b)    increased production of raw materials for agro—industries to increase value added in the country, employment and daveloreMt generally)
a) increased foreign exchange sarningsi
T|
d)    increased opportunities for employment, both by creating mu jobs and by providing more work for the underemployed)
e)    regional devulop3iint in those areas previously neglected*
To these ■&/ be added the social objectives of improving living atjmdardft in the rural areas by improving both the distribution and the absolute level of rural incomes, health and education conditions*4
Investment in irrigated agri culture will advance all these objectives,
hough not all together in the same project and in preparing the investment
rogreuBme the Government ie considering the most promising opportunities for
nveetment and the priorities with regard to overall national development
olicy*
The review of projects for irrigated agri culture carried out by VADA in
978   with   the   PAO   assistance   (TCP   Projeoi   6/e?TH/o1/1)   took   into   consideration he major groups of faotors for each project t
-    physical factors;
-    demographic and infrastructural factors;
-    development fact ore (capital items T operating oorta, agricultural benefits)*
It resulted in the ranking of projects and within this ranking the
"irst 20 projecte were :
Ranked Projects
Qroaa Irrigable
Area
^inoha
6 500 Ba
Dabous
15 000 Ha
Alwerc
10 000 Ha
Potential for
Additional Rafnfed
~~Awa~
Area n*a«
10/15 000 Ha
10 OOO Ha
Lower Ono (primary Behetos)
3 000 Ha
ManROura Agordat
40 000 Ha
Lake Zwai
5 000 Ha
Tibi, la
7 800 Ha
Tessenie
24 000 Ha
Mara Gala
18 000 Ha
Chew Bahir
1 2 500 Ha.
Code West (independent of dam)
8 JOO Ha
Setit River Bank
30 000 Ha
East Megueoh
6 000 Ha
Arsa n«a.
West Megueeh
7 000 Ha
Awash Lower Plain
63 000 Ha
Upper Guder
5 000 Ha
Angelele Bolhamo
14 000 Ha
Gilgil Abba!
24 000 fU
Gode South (dependent on regulation)
19 200 Ha
North—East Tana
5 000 Ka5
With consideration of other factor* affecting project priorities (such u government policy on development, sire of projeote, adaptability to phased implementation, ease or speed with which project oould be
Implemented, eto*,) 10 projeate were re looted :
Priority
Project
Pollow-uu soil co required
1
Dabcue
feasibility study
2
Lower Coo
prs-fsasibility study
3
Alwere
pre-faasibillty study
4
Gode Meet
feasibility study
5
Mansura Ago rd at
pre-fsaaibility study
6
Awash Lower Plain
final design
7
Chew Bahir
pre-faasibllity study
8
Pincha
final design
9
East anl West Meguecb
feasibility study
10
Angele 1 e Bolhamo
updating    of    feasibility 
study
and final design
The Indicative  Investment Programme prepared by VADA with the PAO
asoistanca Is still
consideration but with the preparation of the
national budget for  the next fiscal year         the neooasary arrange wonts haw been made in order to provide the adequate budgetary resources to 7ADA*
The Government has the intention to increare the efforts ud to devote more reeourcea for the development of irrigated agriculture in the Valleys of Ethiopia* The Government has already taken decisions regarding the various project a to be implemented and/or prepared during the first phase of the Investment Programme* Amongst these epeoial mention Bust be made on projects to be covered by the activities of the UKDP/PAO Development of Irrigated Agriculture Project (ETH 7B/013)»
( i ) Lower Cbo and Chew Bahlr Prejeote
Both projects will be studied at a pre-feasibillty level in order to assess the real potential of these two areas and to decide if more remomreefl should bo devoted for the preparation of those projects.
They have been eel acted since they wore well ranked according to the basic recking criteria and also because of their significance to the
overall development of Gamu Gofa : food deficit areas, pomplament to infrastructure development (construction of all weather road) and t■traw they will provide come capacity for settlement of local population*-6
( il) Peaslbility study for ana or both sreM in Oesra Oofs
Aocording to the conolusiane of the pre—feasibility phase, the
per*tion of project(s) will be carried out in order to haw a bankable
project ready to be submitted to financing agencies.
(ill) Pabons Project
The preparation of a feasibility study for this project is considered
as a major activity planned for the first phase of Investment Progress*
It   has   been   eelooted   because   to   Its   very   high   ranking,   beoauss   of   its general     significance     of     government     policy,     especially     to     regional     develop sent,   and   its   substantial   capacity   for   sett   lenient   from   outside   the   region* Development    for    rainfed    agriculture    within    the    project    area    sight    start    in an   early   phase   and   its   integration   with   irrigation   makes   the   project particularly attractive*
2* The Dab out Project
2.1        Development to date in Wollega Region
The Dabcus Project ie located in the North-Western part of foliage Administrative fogion.
follegs (Kefle fisgorl
Population (1975)        : Urban
Rural
Total
Ar»i (in k>*) t 71 200
Denaity of rural population 1
ftnber of rural bcuaataolda 1
67 300
1 700 600
1 767 900
24/fas2
378 000
Tha available agricultural atatiatica ar* aoaewhat qtwtiooable i*. they are to be used at a regional level, Howavur, tha reenlta of the
■»*11-eoala agri cultural aaeple cenaue 1976 - 1977 ^e util lead in presenting a reasonable asaetenant of preaent altuaticn.
/...7
Cropped Area in Wollega (1976 - 77.)
Area
(in 000 Ha)
field*
(T/Ha)
Production
(000 Tons)
Taff
180.2
0.760
136.8
Barley
26.3
0.710
18.7
Wheat
6.7
0,460
3.1
108*7
2.000
218.4
Sorghum
60.4
O.84O
50.9
Millet
29.1
0.980
28.4
Horse beans
9.0
0.720
6.4
Chick peas
2*1
0.350
0,7
Field peas
3,5
0.420
1.5
Lentils
0.2
0.130
0,3
Oilseeds
24.9
4.6
Permanent crops
53.4
TOTAL 504.5
The average  farmed ana per family ia           less than 1.5           Ba« Hciwawi the   region   ha*   a   great   reserve   potential   that   could   be   developed   in both directions i r* infed and irrigated agriculture*
2,2   The Area to be Developed and lie Charaoterisilo*
The Dabous Development Area lie* in the Ifortb-Weatern part of Wo 1 Legs Administrative Region, approximately 40/60 kilometers east of Asoea at
10° 10* North and 34° 55' East, The area la located in the lower valley
of Dabous river, on both side of the river (see attached Figure 1)«
Fbjslogrephy
An area of approximately 30 000 ha suitable for agricultural davelopmemt has been selected during a study of the Tend and Hater H*e<ruroee of th*
Blue Nile Basin completed in I964 by the US Bureau of Reclamation* Th* are* 19 characterised by a vide entrenched natural drainage system* ffi—rom snail side drainage enter th* river within the project area*
Slopes parallel to the main ridge average about 1)1, but usually are in the range of 0*5 to 3& The aide slope* vary considerably but are estimated to average 4 to 6^. Slopes of 8 to 12% are comtnon, psrtioularly in Clam* 3 land areas.8-
The best topography lies is u area near the osnter of the project and north of the river : it is a broad smooth plain totalling sows 5
The projoot lands lie within the elevations of 950 and 1 15^ meters.
Climate
The area has a subtropical olimats and liee within the "IC’olla" or
warm sone. There are no meteorological station exactly representative
for the area* However, the 1 050 meterfl elevation and some extrapolated
data from stations adjacent to the area but at a higher elevation, suggest mean annual temperature of ?5°C with a range from 12° to 3O°C« No frost
or near freezing temperature are anticipated* Precipitation is expected
to average 1 000 mm. annually with the bulk ooouring from June to Septemberi average annual evaporation should be about 2 000 ukd* (fcservations are available from the nearest station (Class 2) located in Asosa, at approximate elevation of 1 665 meters above eea level*
The means of monthly rainfall and temperature are shown in the following table :
Table 1     : Temperature and Rainfall in Asoaa (196 3 - 1975)
Month
January
February
March
April
Kay
June
July
August
Septonbar
October
November
December
Mean Rainfall
(nm)
0.8
6.6
19.7
73.4
113.2
217.3
257.4
234.4
214. &
146.8
25.5
0.B
Mesa Daily Temperature °C .
Maximum         SHn-jimm
29.6
31.0
31.6
30.2
27.4
25.1
23.7
23.8
24,9
25.5
26.8
.. •■;' 28.4....
13.4
14.7
15.4
75.3
15.1
14.6
13.9
14.1
14.4
14.2
14.1
• .7 Annual
1 310.7
*• *• • 
27*3’•■7
'1
' ■ I • ■ I9
Hydrology jmd Water Resources
The Babeus river Lb the main fltream within the Bateaus valley, and the irrigated, development project will be utilizing the water of thia river.
The Dabous river drain* a total area of approximately 14 400 square
kilonjeterB before joining the Blue Nile River. It originates in the high
volcanic mountains to the south and flow* generally northward into a large
and flat baain known afi the Dabous swamp, then continues northward to the Blue Nile. The Dabous swamp covers an area of approximately 900 square kilometers of a total of 8 0J0 square kilometers of drainage area above the swamp outlet. The swamp has a considerable controlling effect on the flow
of the Babeus river, and it also has a considerable consumption of water
by plant a and evaporation. The Dabouo receives more rainfall over a longer period than the rest of the Blue Nile Basin, however its runoff vs. rainfall
ratio is rather low due to the effects of the swamp.
There is only one river gauging station on the Dabous, about 20 tan. upstream of the probable diversion site. The drainage area at the gauge
and diversion are 10 100 and 10 440 square kilonuaters, respectively. The station consists of a staff gauge, a water level recorder, and an overhead cableway. The observations which started in 19^1 are of discontinuous
nature. A considerable number of current meter measurements were oonducted and a rating curve was developed, relating the gauge heights to discharges. Figure 2 presents the monthly maximum, meat. aad minimum flows of the Dabous river at this gauge site.
Upto the present no water samples from the Dabous river were chemically analyzed, however according to previous studies the water in the Blue Nile Basin generally show a low sodium (alkali) hasard, and a medium to low, and low salinity hazard. Nevertheless, water samples will be oolleoted in the
very near future during the dry season and the results of the chemical analyses will be available before engagement in the topographical survey
and the feasibility studies*
Geology and Groundwater
The Dabous river originates in a high range of mountains composed mostly of volcanic rooks overlying precambrian and metamorphic rooks. Downstream of the source, the Dabous swamp was formed primarily by flows of basaltic lava which filled in the drainage aystema and damned, off pre viously eroded valleys. It is believed that the major portion of swamp
area is underlain by these younger volcanic rocks.1
The project area iH situated in ar ancient '/alley of the Daboua river overlying metamorphous and granitic rooks of precambrian age. Finesto coarse-grained quartiitea, phillitee, marble, green st one , schists and
gneisses may be found*
It appears that the soils in the area were deposited as alluvial
outwash materials from the surrounding obountains, and have been sub sequently modified and developed by weathering and erosional factors*
The Dab Ous river flows through ths project area from southwest to northeast and drops into an extremely deep narrow canyon prior to leaving the area. Jhiseraua small side drainages occur and approximately ten major side drainages enter the river within the project area.
The geology of the Blue Wile Basin, with its fairly tight basaltic
cap covered with slowly permeable clays, and the eoarcity of ground water outcrop In the deeply eroded canyons do not suggest the presence of large quantities of ground water. At the project area, an extensive exploration program would be required to identify and evaluate ths ground water potential* Presently, utilisation of ground water in the Blue Nils river
basin is limited to flow from springs, hand-dug shallow wells, and a few
deep wells that have been drilled to obtain a potable water supply for municipal am domestic uses.
Soils and landtFee
Three major types of soils occur in the area, namely, ths red latosols, the brown intergrade latosols, and the black grnmusola.
The red latosols, oovering majority of the area, have exoellent structure| good permeability, good water-holding capacity, and they are easily tilled. The brown intergrada latosols, with similar properties to
the red latosols but of lower penuablity with slowly permeable subrtratia, oooupy about 40$ of the area. The texture of these soils is clay through
out. The third group, the grumusols are of minor import an os, comprising only about 5 - percent of the irrigable land. Tbese soils are dark grey
to black and are of clays with very low perma ability which crack very severely whan dry*
The available land classification was of suture oormai so an oe level mH probably subject to considerable error* The land classification saps u> available at an approximate scale of fl 100 000 which were prepared baaed on11
1:^0 00C scale aorial photography* Sampling was conducted by mean* of a helicopter, taking samploe at intervals of 6 - 21 kilometers# Based on i
total of 21 namples, the total arable area of 30 000 hectares io clast nj’-
aa Class 1 - 1 300 hectares Class 2 - 16 420 hectares Class 3 - 12 000
Presently the project area is not widely fanned. Small plots of dryl^M sorehum,               sesame and cotton are grown on a United basis, and goats donkeyo ft« raised in small numbers. Land is plenty and the farmer®
shift from one area to another every tew yearo, aue to the depletion of soils
and infestation by weeds.
2.3  The Suggested Development Programme
2.31 Status of Studies
The Daboufl Irrigation Project was identified during a study of the Land and Water Resources of the Blue Nile Basin carried out from 195®
by the United States Bureau of Reclamation. The investigations under the
so-called "Blue Nile Study" have been conducted on a limited reconnaissance level# They are in sufficient detail to permit the preparation of a general
plan and a rough comparison of benefits and coats as a guide to feasibility.
They provide a guide for the selection of projects for early development. Suhsquent to this no further studies have been undertaken with the exception
of data collection pertaining by hydrometeorology in and around the project area.
Topographic mapping for the area are available on a scale 1(250 000 and contour interval of 100 meters with supplementary contour of 50 meter intervals The maps are based on 1:50 000 scale aerial photography flown in 195? — 58 and were produced in 1973# Topographic nape are also available on a scale of
1:20 000 compiled by photogrammetric methods from the same photographs* Contours are plotted on 20 meter intervals.
There are no climatic data for the project area. The nearest meteoro logical stations are Asosa (a Class 2 station) and Nandi Bubssel and Manghs (Class 4 stations), all situated in the surrounding highlands. There is
however a stream gauging station on the Babeus, u pat re am of the projeot area. The station was installed in 1961 and consists of a staff gauge, water
level recorder and an overhead cableway. Discharge records are available si neo 1962 with some intermittent gape*
19^4 0* 0»-12 -
Land classification maps at an approximate scale of 1:100 000 were produced for the project area. Even though water samples were not taken from Daboua River, waters in the Blue Nile Basin are generally considered table suitable for irrigation*
2*31 New Data to be provided. prior i d t he Feasibility Study
The Valleys Agricultural Development Authority, through the Happing Agency, is presently arranging a subcontract for the production of new
aerial photograph (covering approximately an area of 5^0 kn contact
2 , ■
scale 1:20 000) and orthophoto mape (covering approximately 250 km at
1:10 000 scale with 2m. contour intervals, and 1m* interpolated contour
intervale).
It is expected that the aerial photographs and map® will be made
available on 1B* of May 1980*
2,32 The Indentifled Project
The development plan of the irrigation project includes a diversion dam,
a main canal, a major siphon crossing the Dabous River to convey water to the
lands on the west aide of the river, three principal canals, a distribution
and drainage system for irrigation of 15 000 hectares of land* The features
of the project are shown in the attached general plan ^see Figure 3)*
The diversion dam would be constructed upstream from the project lands
at approximately the 1 100 meters contour crossing, The weir seotion with
top of dam 4 meters above streambed* Stoplogs will be used to raise water
level for diversion into the main canal* Canal headworks would be constructed
on the right abutment of the diversion dam*
The main canal ia an earth canal 17 km* in length with an initial capacity
of 17 cubic meters per second* The three principal canals are all unlined
canals with a total length of 99 km.
A major structure of the canal system is the Dabous river siphon* It
would be approximately 1km. long with a capacity of 11.3 cubic materfl per
second, and would ba a monolithic reinforced concrete structure to withstand
the high hydraulic head.
Water  distribution  will  have  the  problem  of  crossing  drainage  way  and thus   numerous   struct   urea   will   be   required   to   protect   the   canals*   Drainage canals are to be connected to natural drainage ways*
2B-
, , runoral ^jgctive of_the Study
3-1 —
The present background paper intends to define the general framework
for  a feasibility "tidy of the Dab cub project and in requesting from the
invited consultants a proposal for a program of atm  the following
y
^jor aspects are to be considered in the preparation of the pr^gr**—* f
f i ) The level of the study referred to in the present paper as
"feasibility41 grade is the level which 1b usually required to be submitted for appraisal (before loan approval) by sajor international financing agencies ouch as World Bank, IPJLD, EIP «to *|
t
(it) lbs study should cover a development area of approriBately 30 000 ha* However, two very distinct aspects should be kept in consideration I
~ the irrigation project and its site and orientations will be
determined by the water resources and agro-a coned o const derail on* j
- the rainfad area : since the Dahous Valley area prsse**s a very high potential for agricultural development (climate is ideal for
a wide variety of tropical and sub-tropical crops; reconnaissance level information indicate that soils have generally good potential suitability for irrigated and raiufed agriculture), the area could
be developed on an integrated agricultural basis : 10 to 1? 000 ha* for irrigation and 8 to 12 000 ha* for rainfed agriculture*
'Hie complementary nature of these two agricultural practices Is a aajor justification for the economic worthiness of the project* Under the looal conditions the profitability of separate development of highly mechanised Tainfad agriculture could be questionable*
(iii) By thin stage, the project concept and scope have been established* Nevertheless it is still possible or advisable to have then to be reformulated in view of changes in political or economic conditions or
as   a   result   of   further   studies*   Therefore   technical   alternatives   and their economic implications are of primary importance*
These are not detailed epeoifi cat lone, which aw to be provided by the ^ultant a in their propels, but .hould be oonaidered M guideline, or
es of technical specifications*14
The following surveys, studies and activities are suggested to be included in the study in order to achieve the objectives of the study
defined in earlier paragraphs* The surveys, studies and nativities will include but not be limited to :
3*21 ftesouroefl Surveys and Ana lyssa
Meteorological and Hydrological Data
All relevant hydrological, hydrometeorological and agroolitnatologioal data on the project basin will be col looted and analysed for the purpose of determining water availability, water require men ts and control techniques for various crops* Data on similar has in a will be collected for generation of data by correlation techniques or by other synthetic methods as nay be necessary to assess, evaluate, and plan utilisation of the resources of the area* In determining the water availability and the extent of the develop ment area, risk criteria acceptable to IBRD and to other international financing agencies will be employed in anysis, Additional data requirements for the following phases of the project will be identified, and data gathering staticn(s), including Class 1 type meteorological, will be established, and local observers will be trained* Necessary equipment is expected to be provided by the Government*
Soil Sunray and Land Evaluation
Based on 1:50 OOO (existing) and 1:20 000 contact scale aerial photo interpretation, and from field work first a reconnaissance level survey of 30 000 hectares, then a semidetailed soil survey of approximately 20 000 hectares will be carried out in the project area* The survey is to include an overall observation density of at leant 1 per 5° hectares, of which at least 25% are to be pits* Borings are to be to a depth of not less than
120 oen timet era and pits to a depth of at leant 200 centimeters* The major soil units are to be adequately characterised in their chemical and physical properties, with special attention to testing of permeability, infiltration
rate and available moisture capacity* The soil survey is also to produce a semi-detailed soils map at 18JO 000 scale, and correlated with agronomic surveys, a land classification map at the same scale to suitability sub class within the context of the FAO framework for land evaluation*- 15 -
3.22 Engineering Investigations
Topographical and Geological Surveys
The basic do aments (aerial photography and topographic maps) Mill ba made available at the beginning of the study (see section 2*31 of present
paper). However, some additional surveys might have to be conducted under
the responsibility of the Consultants : detailed surveys might ba requested for bom components of the project (diversion structures, main canal etc.,)
or for sample areas and facilities repree-ntative of topographical,
geological and other conditions. The technical details (scale, etc*,) and
methode should be elaborated in the proposal,
Enginopri ng Works
The Consultants will prepare outline designs and cost estimates for the main engineering works, on farm works and other infrastructural requirements. As already mentioned alternative ah ernes are to be proposed and s comparison is to be made between the alternativee.
The designs will be prepared to a sufficient degree of detail to permit
the significant engineering work quantities to be estimated to an accuracy acceptable for appraisal by the leading financing organisations.
Special attention will be paid to farm irrigation efficiency, seepage
losses and canal waste; in the Blue Nile Study, these were taken an 60 percent,
5 percent and 20 percent, respectively. Soil — water relationships will be investigated on site; the prevailing efficiency and loss rates in other
irrigation projects in Ethiopia will be evaluated for comparative purpose.
The unit cost rateB will be based on rates for similar work in Ethiopia and elsewhere, updated as necessary.
An a special engineering study, existence of possible obstructions at
the swamp outlet, and between the swamp and the project area, will be investigated and proposals complete with cost estimates will be made to increase, specially, the dry season yield of the swamp.
Erosion rates will be estimated and conservation measures will be proposed and costed for hazard locations.
3.2J Agriculture
Agronomic studies will be conducted to optimise cropping patterns for the rainfed and irrigated agricultural development, and the project areas will be determined for both types of development. The irrigation project,
• ■16
and oriental ions will be det-ermired by the water resources and
^p-eeonomio condition*. Various cropping patterns for varying eUes of
irrigated areas will be studied, considering the limited nature of available
water* Also irrigating larger areas and accepting partial failure of water
supply in eowe yssJ's and resulting effects on crop yields will also be studied
and taken into eoonoaioal analysis to optimise benefits*
Crops  and  total  water  requirements  will  be  based  on  cropping  patterns, ^gro-climatological    and    soil    conditions*    The    soil    types    will    be    accurately classified,   and   both   the   irrigation   and   rainfad   development   programs   will   be planned starting with the best soils*
The project and surrounding areas will be inspected for presence of
termit® f
s
if the area iB infested or is in potential danger from termites,
extermination methods, together with cost estimates, will be proposed.
To summarize i The current agricultural practice and marketing will
be studied and an agricultural development plan will be prepared, including recoomendations on farming systems, crops and cropping patterns and rotations,
laiKi preparation and agricultural methods, water managenent, crop protection
and harvesting, irrigation requirements and production programs*, livestock
development etc.
Ecological impact of the proposed programme shall be evaluated, and recommendations will be made, if any, cm possible adverse effects* Specially*
if increasing the dry season yield of the Dabcnis swamp materialises as a
feasible development, the resulting effects on the plant and wildlifs will be
evaluated*
3 <24 Economic and Financial Studies
In   this   part   of   the   stilly,   the   enrhasia   is   on   the   financial   and   economic feasibility of the project, involving a comparison of costs and benefits*
It will include :
—    analysis  of  primary  benefit  (incremental  output  from  farming  as  regards both volirme and prices) with consideration of development period;
—    apecial   consideration   for   the   price   system   to   be   utilised,   with   special attention to market aspects and commodities price projections;
—    the   financial   analysis   with   consideration   of   schedule   for   disbursements and of recovery of coats?-     17   -
A  implications  on  foreign  exchange  situation, 
This  pArt 
of  the study   ie    of 
crucial  importan oe    since  it   will  bring 
together all 
the data relevant  to  the  eoonomio  and  financial  feasibility 
of the projeot. 
2.25      0rganization  and  Management 
Ms chapter  of   the  etudy  i8  concerned  with  ho the 
proieot  would  be 
Aa   end  operated  and   Wi th the Buitability of  the  administrative  manAgo sent  proposed  for those purpOSes, 
3.26   Referonces 
Ia  the  preparation  of  proposal  the 
Gonsultants should rofer to  the 
ai eut  guidelinee  and   methodological  papers And   other  internatioDAl  ingtitutions, 
In partioular  1 
PAO        1976 
prepared  by  PAO,   World  Bank 
A Pramework  for  land  Evaluation  (Boil  Bulletin 32) 
Guidelines  for  the  Preparation  of  Agri oultural  Investment  Project Investpent  Center      FAO,   August  1977 
Operational  Manual  Statement  No,    2. 
28- World  Bank   Ootober  1978, 
Regarding  previoue  studies carTied  out,  the the  following  published  reports  : 
Conaultants  may  refer to 
"Land  and   Water  Resources  of  the 
of   the  interior,  Bureau  of  Re  cl amati  on   for  the  Department  of State 
Bl    ue    Nile  Basin",  U,S,  Depsrtnent 
Agency   for 
International  Development,  1964. 
-"Agrioultural Development 
Kefa'",  Valleya  Agri cultural  Development  Authority  (VADA)   Ethiopia, 
Potential  on   some   Aroas   of      Wollega  and 
Field  Report  No,    1,   1970. 
WOuide   to  the  Development  of  the  River  Valleys  of  Ethiopia" Halerow-ULG  Limited  for  FAO/VADA   1978. 
.../... -     18 
Anpendix I  - Accese, Trangport and  Acconodation 
et to  and   in  the   project area  wi ll require speoial  attention for 
BOVOral reasons  : 
aeA  i8 far  distant  from   Addis   Ababa;   Asosa  is  700  km,    far avay 
.A£dis Ababa  and   it requires  14  hours  driving in  to days: 
+he   projeot  area  iB   located  40  km.   away  from   AsoBA   and  & DAy   access road  has  been  recently  construoted: 
and  the  driving in  the  field  is difficult  (veRetation  and absan ce   of  tracka  to reach  the vari ous   sites  of  the  proieot). 
is  no   ruitable  acconodation  and   faoilities avaflable  at  project  site, 
+he   aooeB8 
.e 
ArCeDt   a  temporary  cAmp   sstablished by  the 
contract or  for the  oonstruction 
of  the  road, 
Linited  accomodation  or utility servioes  could  be  &vailsble 
3, 
in AsoBa 
In  order  to  asaist  in solving these  problens  the  PAO/UNDP  Project  with  VADA 
ill ake  the  following  aTangements  1 
the   vehicles for  the  field  work 
for  long   distan ce   travel  (2   Peugeot  504) ill be  MAde   available  and 
5/6 Land   Rover  and  1 Meroedes  Truck)  and 
operated; 
offi oe  accomodation  in Addis  Ababa  will  be 
provided  by  the  Govermeent: 
camping  equipnent  (tents) vill also  be   made   available; 
but  it  is 
advisable  that  BoDe   Bemi-pernanent 
accomodatin  (caravan  type, 
imported 
or  locally made)  shold be  provided  by  the of   the  team  on   project  eite; 
Consultants for  the  installation 
the   GoverTnent  will 
make   arrangements  to  open  600048 
traca ri thin  the 
projeot  area in  order  to 
facilitate the  varioaa  survoyu  soil,  topography 
and  other engineering  inveatigati ons); 
the  Covernnent  will mae  the  necessary  arrangementa  for  the  accasa ith vehiclos  on   both  banke  of  the  Dabous  Ri ver. 
4. 
1owever,   the  Consultanta ight 
are  requested  (helicopter): it should  be   inoluded  in  the  propoaal, 
oongider  that  additional air rooonnaissanoes 
cerpaTts and 
local  personnel  wil1  normally  be 
provided  by  the  Govrnent 
could  be   aub jeot  of 
negotiation betveen  the 
FAO/UNDP   Projeot,  VADA    and 
the selected Consultant. 40 
THOPIA 
JAFRICA 
P 
M  A 
bsbe 
LI  A 
tefonde 
olka 
RE 
Y       A 
SCALE 
o   50  100       200    300    400  Kn 
qure  |-  Locotion Mop  ot  the  Project  ored 200 
900 
TI 
72 
I979 hi

Summery

Dabous Irrigation Project Summary

Dabous Irrigation Project Feasibility Study

Background and Context

Ethiopia's Agricultural Situation (1970s):
- Population: 28 million (90% rural), growing at 2.5% annually
- Agriculture contributes 50% of GDP and 90% of exports
- Challenges: Soil degradation, small farm sizes (~1.3 ha/family), traditional methods
- Food imports reached 300,000 tons in 1978 due to crop failures

National Irrigation Development

Only about 60,000 ha net area under irrigation in Ethiopia (1980), with major projects in:

Awash Valley (55,600 ha)
Mereb Gash (10,000 ha)
Tessency (10,000 ha)
Wabe Shebelle (3,800 ha)

The Dabous Project

Project Location and Characteristics

Location: Northwestern Wollega Region, Dabous River valley (10°10'N, 34°55'E)

Feature	Description
Total Development Area	~30,000 ha (15,000 ha irrigable + 10-15,000 ha rainfed)
Elevation	950-1,150 meters
Climate	Subtropical ("K'olla" zone), mean annual temp: 25°C, rainfall: ~1,000 mm/year
Soils	Red latosols (majority), brown intergrade latosols, black grumusols
Water Source	Dabous River (drains 14,400 km²), affected by Dabous swamp (900 km²)

Proposed Infrastructure

Diversion dam at 1,100m contour
17 km main canal (17 m³/s capacity)
1 km river siphon (11.3 m³/s capacity)
89 km of principal canals
Distribution and drainage systems

Study Objectives and Components

Feasibility Study Goals

Determine optimal development of 30,000 ha (irrigated + rainfed)
Prepare bankable project for international financing
Evaluate technical alternatives and economic implications

Key Study Components

Component	Activities
Resource Surveys	Hydrological analysis, soil surveys (1:50,000 scale), land classification
Engineering	Topographical/geological surveys, infrastructure design, cost estimates
Agriculture	Cropping patterns, water requirements, termite assessment, ecological impact
Economic Analysis	Cost-benefit analysis, financial feasibility, foreign exchange implications
Organization	Project execution and management structures

Project Significance

The Dabous Project was ranked #1 among 20 potential irrigation projects in Ethiopia due to:

High agricultural potential (both irrigated and rainfed)
Alignment with government development priorities
Significant capacity for population settlement
Potential for regional development in Wollega

Implementation Challenges

Remote location (700 km from Addis Ababa, poor access roads)
Limited infrastructure in project area
Need for additional data collection (hydrology, soils)
Potential ecological impacts of swamp modification

Document prepared: February 1980 by Valleys Agricultural Development Authority (VADA) with FAO/UNDP support