Baro-Akobo Basin Master Plan Study Summary

PEOPLE'S DEMOCRATIC REPUBLIC OF ETHIOPIA
ETHIOPIAN VALLEYS DEVELOPMENT STUDIES AUTHORITY
BARO-AKOBO BASIN MASTER PLAN STUDY
OF WATER AND LAND RESOURCES OF THE
GAMBELA PLAIN
INFORMATION FOR THE TERCHNICAL COMMITTEE
ON THE MASTER PLAN MAJOR PROBLEMS
DEVELOPMENT AT THE II STAGE OF WORK
PREPARED BY THE ALL UNION
EXPORT AND IMPORT CORPORATION
V/O "SELKHOZPROMEXPORT"
USSR - MOSCOW
1989flee-3PEOPLE’S DEMOCRATIC REPUBLIC OP ETHIOPIA
ETHIOPIAN VALLEYS DEVELOPi.IENT STUDIES AUTHORITY
BARO-AKOBO BASIN MASTER PLAN STUDY OP WATER AND LAND RESOURCES OP THE
GAMBELLA PLAIN
INPORL1ATION POR THE TECHNICAL COMMITTEE ON THE MASTER PLAN
.MAJOR PROBLEMS DEVELOPMENT AT THE II STAGE OP WORK
PREPARED BY THE ALL UNION EXPORT AND IMPORT CORPORATION
V/O " SELKHOZPROI.lEXPORT1’1
1989CONTENTS
page
1,   2       General.................................................................................................. 1
3.           Survey work.........................................................................................   1
4.           Project work...........................................................................................  3
4.1.        Conseptions on the development of agricul
tural and induatrial complex of the Baro-
Akobo Valley......................................................................................... 3
4.2.        Concerning the development of section
"Irrigation Systems".........................................................................   ..13
4.3.        Concerning section "Wild life"............................................................ 15
4.4.        Concerning the epidemiological situation
in the Gambella Plain........................................................................   17
4.5.        Water supply of populated areas and
agricultural projects............................................................................. 18
4.6.        Section "Water Supply Analysis........................................................ 21
4.7.        Hood control....................................................................................... 22
4.8.        Concerning estimation of the volumes of
capital investments............................................................................. 271 , 2. GENERAL
1.    The Master Plan of utilization of land and water
resources of the Baro-Akobo valley (Gambella) is being 
compiled in accordance with the order-confirmation
No     7201202800     dated     March     23,     1982     and     the     enclosed     pro gram. Master Plan is compiled in two stages.
The      first      stage      in      the      form      of      Preliminary      Report was       discussed       at       the       joint       Ethio-Soviet       Technical       Com mittee meeting on June 10, 13, 14 and 15, 1988.
in the process of discussions on major conceptions
of the development of Gambella valley stated in the Preli
minary' Report working out of the major topic had been 
evaluated positively.
However, when considering separate sections of the
Master Plan report some remarks and suggestions were made
on expending and improving the materials for compiling the
Final Report.
2.    The second, concluding stage of the Master Plan is
being developed in accordance with the program of the or
der-confirmation on the basis of additional investigation 
and with regard to the corresponding remarks made by the
Technical Committee.
3.     Survey work.
The Master Plan Project team studied additional topo-
geodetic, geological and project materials that appeared 
during last years and which were not envisaged in the
program of the order-confirmation, carried out conside
rable volume of survey and project work, aerial photo 
materials were acquired and studied, there appeared pos
sibility to make use of helicopters to study the areas
inaccessible for ground transport: and to carry out survey 
of the Gambella valley natural conditions using modern 
technology.
Taking into consideration the above, the volume op2
survey  work  in  topography,  geology  and  hydrogeology,  soil study,  geobotanics and  hydrometeorology  had  been  somewhat updated.
The updated working programs with detailed substantiatioi are given in the Enclosure.
The adopted technology of survey ensures getting the scope of materials for all kinds of natural conditions
survey which makes it possible to settle all the questions within the Master Plan Project framework.
To characterize Gambella valley natural cohditions it is envisaged to prepare the following specialized maps at the scale of 1:200000.
Geology and Hydrology
1.    Actual material and degree of study.
2.    Geomorphologic.
3.    Ground water level depth and chemical composition.
4.   Hydrogeological.
5.    Engineering-geological,
6.    Cover beds deposits.
7.  Hydrogeological and reclamation zoning.
Soil and Geobotanic purvey
1.    Soil map.
2.    Soil-reclamation map.
3.    Geobotanic.
4.    Pasture lands.
Hydrology
1. Climatic and hydrologycal map.
Besides, 
maps
of
various
scale
s
with 
specif
ication 
of
natural
conditions
of
indiv
idual
proje
cts
and 
repre
sentative plots will be submitted as well.3
4.  Project work.
Project work connected with the development of the
Gambella valley economy and utilization of its potentials
is carried out mainly within the volume of the order
confirmation program and with regard to the remarks of the
Technical Committee for the Preliminary Report.
Corresponding clarifications are included into this
information on some remarks anc^suggestions of the Tech
nical Committee which go beyond the requirements of the
Master Plan Project or considerably deviate from the re
quirements of the program.
Taking into consideration the importance of project
work on agricultural development, brief statements of major
conceptions of its development suggested by the Master
Plan are given below.
,4.1. Conceptions on the development of agricultural
and industrial complex of the Baro-Akobo valley.
4.1.1.    General aim of the development.
Growth of the level of social and economic development
of awraja Gambella on the basis of utilization o£ natural
and manpower resources of tiie Baro-Akobo valley.
To achieve the general aim it is envisaged to solve
the following major tasks:
-   increase the volume of agricultural production and 
reliable supply of the region with food products on the
basis of feeding norms for one man per day: by the year
of 1995 - 2400 klcal, by 2000 - 2500kkal, by 2005 -
2600kkal and by 2010 - 2700kkal.
-   maximum involvement of the able-bodied population 
into the production sphere;
-   improvement of social welfare of the local and 
resettled population';
-        increase     of     the     income     of     the     population     with     the corresponding       development       of       trade       turnover       within       the region;
-   expanding the volume and range of the export products alongside with the corresponding improvement of the4
balance of the payments of the country.
Two major alternatives (programs) for the develop ment of awraja Gambella are suggested to achieve the
above tasks.
4.1.2.    Program "Minimum"
Ln accordance with this program it is envisaged guaranteed supply for the increasing population of awraja Gambella by the food stuffs of their own production inclu ding reserve fund in case of unfruitful year. At the same
time production of commodity products is envisaged within the limits of the adopted crop rotation and structure of agricultural crops (Raw cotton, cotton seeds, oil crops)
and their primary processing at the ginnery and oil re
finery.
At the prospected level of regional development under the alternative "minimum" full employment of the able- bodied population is not achieved. Upto 75% of the available manpower resources can be provided with work.
There are different alternative ways of achieving 
the tasks of the program "minimum" stated in the sections 4.2.1. and 4.2.2.
4.1.2.           1. Alternative with priority development of irrigation
This alternative of the development of land resources envisages:
-    preservation of the already existing landownership and the achieved level of the plant-growing production 
(26.6 thousand hectares of arable land);
-   puttind into exploitation 10.4 thou.ha of irrigated lands of the Alwero project by the year 2000.
-   putting into exploitation lOthou.ha of rainfed lands by the year 1995 and establishing 4 state farms on those lands;
-   putting into exploitation I3.5thou.ha of new irrigated lands in the period of 2001-2010 and establishing 5 state5
fRTrnJs on those lands.
Implementation of the above will make it possible
to achieve complete self-sufficiency in pl^nt-growing food 
products in the region. The region can move from category 
of traditional consumer (importer) of food products into 
the category of goods producer.
Calculations     show     that     by     the     year     2010     in     the     Baro- Akcbo      plain      in      all      the      categories      of      farms      with      60thou.ha of      total      arable      land      can      be      achieved      the      following      volume of agricultural production (thou, tons):
grain  - 66.4; lagumes - 10.5; groundnut - 20.6; sesame seeds - 2.4; raw cotton  - 40.7; vegetables and  roots - 44.5; fruits - 16.6.
’.Then all the requirements of the region are completely 
met it is estimated that there will be left in the form of
commodity products: grain - 18thou.t; legumes - I.Othou.t;
raw cotton - 40.7thou.t.
If the ginnery and oil refinery are constructed the volume and varieties of commodity products will be increased.
4.1.2.          2. Rein-fed alternative
This version is considered as an alternative to the variant with priority development of irrigation.
According to this alternative it is envisaged to make use of all the categories of the existing arable lands
of 26.6thou.ha, development of I0.4thou.ha of irrigated lands of the Alwero project and lOthou.ha of new rain-fed lands stipulated by the version with priority development of irrigation.
However, instead of 13.5thou.ha of irrigated lands in the period of 2001-2010 it is planned to develop 
61.3thou.ha of rain-fed lands.
Under the rain-fed alternative total planting area for agricultural crops will be 108.3thou.ha including 97.9thou.ha of rain-fed lands.
Under this alternative the volume of agricultural production is estimated to be close to that of the first version and, as a whole, sufficient to meet basicrequirements of the Awraja Gambella population and to 
provide raw materials for the proceeding industry.
By the year 2010 gross plant-growing production for
all the categories of farms can be (in thousand tons):
grain - 67.4; legumes - 12.0; groundnut - 21.6; sesame
seeds - 1.7; vegetables and roots - 23.2; fruits - 4.5;
raw cotton - 43.4.
Requirements       in       manpower       resources       engaged       in       plant growing      in      comparison      with      the      main      version      will      increase from 12 to 23 thousands of able-bodied men.
4.1.3.    ‘-lain directions of livestock
development
Suggestions and recommendations for the development of livestock breeding will be given in the blaster Plan 
in general without detailed consideration. The major of
them are:
4.1.3.          1. For central non-flooded area
of the plain:
Cattle breeding development
In the central agricultural zone which is not flooded during wet season it is recommended to set up animal farms with dairy orientation under each newly established state farm with the aim to provide with meat and dairy products both the state farms personnal and the personnel of pro ceeding industry and other organizations in Gambella and district centers.
However, taking into account complete lack of expe rience in livestock breeding in this area and for the time being the lack of guaranteed means to fight tripanosomosis, it is recommended to start with setting up of 2-3 experimental animal farms on the basis of the existing state farm
"Abobo", in one of the state farms "Alwero" and in wereda Gog-Jor on the basis of the local breed "Abigar".7
If the results are effective, Ln 4-3 yearw lit In 
experience oan be transferrod to other state farms Ln 
agricultural zone. At,tho same time Lt Ln <dvi«ed. mi a
sort of experiment to Import Into the agricultural zone
twill herd of dairy oown of lOuropfcan broodn or hybrids to 
keep nt those farms,
ReoommendatLonn          for          oatabllohlng          experimental          farm and      its      technical      and      ooonornlo      indexes      will,      be      given      Ln the final Report.
Proceeding from tho planning volutnon of grain pro duction In tho region to moot tho Increasing require
ments of tho urban population of tho awraja with poultry moat and eggs It Ln recommended to establish Ln Gambolla poultry factory for Go thousand laying hens with annual capacity of egg produot.lon of 1 2mln p Locos. Poultry raising at tho personal households of tho peasants oan bo 
of great help for tho production of poultry moat and 
eggs. In this connection it .Ls advised to net up coopera tives for purchasing of poultry and eggs find for Laying
in and selling to tho rural population of fodder to bo 
used at their households. To provide tho population on a regular basis with chickens for fat tons Ing It in recommen ded to set up an incubator station in Rambo I la.
4.1.3.          2. Woatern part of the Buro- Akobo plain
To improve social and economic state of cattle- breeders-nomads and to develop livestock raining the Master Plan envisages that the following In to bo accomp lished:
-   construction of all-weather road for vehicles which, io to Link up the centre of awraja with the most populated areas of the western region;
-   establishment of agricultural associations by uniting cattle-breeders (300-400 families) with the number of cattle 4-6 thousand heads Ln each association;-    establishment of associations’ centres in the areas adjacent to the projected road;
-    implementation of the Master Plan proposals for watering of productive pastures and observing pasture rotation with the aim of their more effective utilization.
Approximate volumes of commodity products (meat, milk, hides) which can be purchased in associations will
be given in the Master Plan.
Under all circumstances it is not recommended by the master Plan to disturb traditional system of pasture keeping of the cattle and to introduce any changes into 
the breeds of local cattle.
In view of the fact that at present density of
cattle in the areas of productive pastures is high, 
further growth of cattle population in the nearest 15-
20 years is not recommended.
4.1.4.        Development of fishery
Development of fishery envisages:
-    development of fishery in the complex hydroworks to be constructed;
-   establishment of pond fishing farms;
-    organization of new fishermen’s cooperatives for fishing in the rivers and lakes of the region;
-    organization of storage, processing and transportation of fish products to the consumer.
By the year 2010 it is envisaged to ensure annual consumption of fish at the level of 18.5kg per head.
4.1.5.    Develop.-'ient of proceeding
industry
Construction of industrial facilities is envisaged according to the projected volumes of commodity production in agriculture. Agrarian and industrial base of the
region should have the following enterprises:
- in view of remoteness of grinneries from Gambella and correspondingly high transportation of raw cotton -9
270 birr/ton which comprise 21.4% of the raw cotton cost, 
it io recommended, to construct Ln Gambella ginnery with 
the annual capacity to process 40-43thou.t of raw cotton. 
Estimated cost of its construction is about 3mln.birr;
-   to process cotton seeds and other oil crops it is
recommended to construct in Gambella oil refinery with 
annual capacity to process 23-25thou.t of seeds. The
refinery is to be put into operation by stages starting 
from 1995. Estimated cost of its construction is about
1.5mln.birr;
-   if the results of the experiment on cattle breeding 
are positive, it is recommended to construct in Gambella
a dairy factory. Dairy units of state farms and purchase
from the private sector will provide milk for it;
-   to provide Gambella population with bread it is
recommended to costruct bread-ba’cing factory with the
capacity of 8t per day.
Estimated cost of its construction is 830thou.birr.
4.1.6.    Program "Maximum" with orientation only on_
in-regional manpower resources
If economic and material facilities are available in the country, in addition to the program ’minimum with 
-
priority development of irrigation, commodity production 
in the Gambella plain can be considerably increased. 
To analyse the possibilities of such increase the
master Plan considers the alternative which is conven
tionally called program "Maximum".
This name doesn’t tell that all the potentials of
the plain for agricultural development are utilized to 
the maximum.
This alternative considers the possibility of increase
of commodity products in addition to the possibilities of
the program minimum under the cohditions of maximum utili zation of in-reginal manpower resources for the period 
up to year 2010.10
According to the program maximum taking into account
favourable bioclimatic conditions for sugar cane growth 
in the Baro-Akobo plain it is recommended to set up sugar
complex.
First plantations of sugar cane under the program
’’Maximum" are advised to be set up on the area of 13 thou.ha
(net area) which will make possible to produce 180-
190thou.tons of sugar annually. This will allow to double
sugar production in the country and to decrease the
existing deficiency to a considerable extent.
Besides, the currency which is spent to procure this
production will be economized.
To     achieve     the     aims     of     the     program     "Maximum"     in addition        to        the        activities       stipulated       by       the       program minimum it is envisaged:
1.    On the basis of social and economic criteria to substantiate the optimal alternative for the location of the first sugar complex (sugar cane plantation and sugar factory), comparing the alternatives of their location
in wereda Gog-Jor on the right bank of the Gilo river (between the Tata lake and Ubela settlement) and on the right bank of the Baro river, 24km to the west from Itang settlement.
Under both alternatives sugar cane planting area will be 18000ha.
2.    To establish experimental sugar complex (sugar cane plantations in the area of 1000ha and sugar factory with annual capacity to produce up to lOOOt of sugar)
and the subsequent spreading of practical experience for the larger complexes.
The major task of the experimental complex will be testing of various sugar cane varieties, study of agro technics of cultivation by seasons, optimal norms of mineral fertilizers application and its efficiency, study 
and development of optimal irrigation and watering norms according to the stages of cane growth and carrying out experiments on disease and pest control in the Gambella Pl ain area-11
The experimental complex will also serve as a
school for training personnel for the main complex. 
To facilitate implementation of the program '’Maximum"
it ig expedient to establish the experimental complex 
in the shortest time possible in order to get the neces
sary recommendations for sugar cane growing at the soonest
The main complex is advised to be established on 
the basis of 8 state farms with net area of 2250ha each. Estimated capital investments for the complex (without
cost of hydrotechnical and irrigation construction) is
732mln.birr including the costs for housing and amenity 
facilities construction which will comprise 4o.7thou.birr
per a hectare.
Besides, it is recommended to construct in Gambella
an alcohol factory where molasses obtained from the sugar
factory will serve as raw material and also a distillery.
4.1.7.    Exploration of other possibilities
for commodity and export production in the Gambella plain
It is envisaged to give estimated economic evaluation of expending of production and transportation of various agricultural products to the external market, namely:
-   to evaluate facilities for production of fruits and their possible by-products (bananas, -pine-apples, citruses, papaya, mango);
-   to estimate the costs for export of those products from Gambella and to determine approximately the countries- importers according to the corresponding levels of agri cultural production.
4.1,8.       Evaluation of utilization of lands
not specified in the programs
"ilinimum" and "Maximum"
Gambella plain lands potentially suitable for culti vation in the non-flooded area and not specified 12
in the program "Minimum” and "Maximum” will be also evaluated to determine expediency and priority of their development.
Characteristics of these lands will be given in the Final Report in accordance with the directives stated in 
the minutes of the Technical Committee meeting on the discussion of the Preliminary Report of the Master Plan Project on June tO-15, 1988.
Recommendations for agricultural development and utilization of lands in the western (flooded) part' of
the plain will be given in the Final Report with regard 
to the studies carried out by TAMS in 1975 and Euroconsult in ‘977 and additional investigations accomplished by 
the Master Plan Project team.comic IL OF MINISTERS
Ministry of Industry
Ministry of
State Farms
Southern Agricultur> Devi.Corp.
Cotton
Dev’t
Corporation
Enterprise
Enterprise
^tate Farms
Ginnery
-   Maiae
— Sorghum
~ Rice Groundnut Soybean
State Farmr
---------- SL£iZ
J
>L?Z-7Z32_k
'>
rL^.-Jj ?L£j
t i>
/JzS
1(3:       Each section will ’oe controlled by a aa^er at section sheecatd l ionevel who will be responsible for development , has bandr;/, cane supply, and laboar management in thatORGAN ISAl'TOR CHART = SUGARCANE PROCESS IbIG KLART
FACTORY MA1MG £R
1    ELECTRICAL  ; ’sUPER IRT-
<ENBENT
r
1
Engineering manager
1__ _____  „
—............ -......... .
AREA iMAINTEHANCE i
—
'SUPER INTE- i
^BERT—_______ 1
WORKSHOP SUPER INT- | ENBENT
—_____________ 1
f'3l##
1
4<2 1  section ’’-rrigation systems’  is being elacc- ra-8G in accordance with, the progrpri of order-confirza— tion and renarks of trie Technical Coznit tee on Prelimi nary Report.
”?epeo” experimental plot, designed by the Rnro consult
firm with allowance for additional investigations performed 
by the Paster Plan group in the western part of the
Gambella Plain.
While designing the data of analogue projects of irri
gation systems in other regions of the country are taken 
into account.
4.2.3.        In order to avoid soil erosion during irri
gation and rainstorm precipitations and to create optimum
conditions for gravity irrigation the lands with slope
up to 0.02 are chosen as irrigated lands.
4.2.4.        The efficiency of irrigation systems is
adopted from 0.60 to 0.65.
4.2.5.        The regime of agricultural crops irrigation
is       calculated       by       Blainy-Criddle       method.       The       80%       probability year is taken as the design one (FAO recommendations).
4.2.6.        While choosing lands, recommended for irri gation, when gravity irrigation possibilities are not
available, the water lift height by pu.up stations from water source to the irrigated area is adopted not more than 50.0m.14
4.-.    .    .    The    height    of    walla    which    protect   irrigated lands      front      flooding      is      calculated      for      the      10#  flood probability level.
4.2.3.       The structure of a separate irrigation system management and the structure of interbasin manage rent of irrigation systems organization in the Gambella Plain are given in attached organogranma no 1 and ho 2.T n Bex’—llri a In Irrigation Systems Man ng ein ent (IBISM)
Gnxnbella.
administrative subordination line 
operational subordination line••iter 'ivpoiuveo
i I'evelpptaent Authority
” llb<> J n— Pt\nlm 1 Project Control
I stago
I
L
, "Alv.ero" Project ; Control Centre (PCC)
I
Inter-Basin Irri
gation systems Management
Gambella (IBISM)
Sugar Complex
Project Control
Centre
I
I
operational subordination line15
4.3.      Concerning section "Wildlife11
In the piocess compiling the second stage of the
Easter Plan the air visual counting of wild animals and additional investigations of their habitats were carried 
out with the help of helicopters and with direct parti
cipation of Gambella National Park and Ethiopian Wild life Conservation Organization (WLCO) representatives.
In connection with this the recommendations regarding wildlife protection proposed in the Preliminary Report
are somewhat updated.
The organization of a nature reserve in the south western part of the plain which way proposed earlier is considered to be inexpedient. This decision is taken due
to substantial water logging of the territory under con sideration and by the fact that it is impossible to 
include into the reserve the annual area of wildlife to 
be protected.
It is recommended to reconsider the boundaries of the existing Gambella National Park having taken out the territories which are subject for the intensive manage
ment development. It is proposed to include into the National Park two large areas: the lowland one in the west
(418 thousand ha) and the woodland one in the east (301 thousand ha).
The detailed designing and functional division of the National Park territory into zones, including the infrastructure development during the Master Plan ela boration are not being performed. This job requires to carry out special arrangements for hunting.
It is prooosed to organize an experimental farm with semifree keeping of big antelopes. The territory which is recommended for this will be shown on a map of the 1:200000 scale.
It was found out that there are the necessary con ditions to organize farms for crocodiles and ostriches raising in capacity.4.4.     Concerning the epidemiologjcrj situation in the Cambella Plain
17.
In the Protocol of the fp ^- ■
in iQnn ■>+ • 
o
June      10-15,      1930      it      is      pointed      out      that      th.      . 
cnnical Committee dated
opldemlolOEZ in the report is elaborated t Problea °f
spectrum than  it is needed  by  the Order-confl™'* 
program-
r  conflation
At the came time the Ethiopian <Hd«
tinue         the         norh         on         the         epidemiological         nltuaZTstu™
x 
to additionally study the problems
f Vt , 
/ P^ooiems Of spreading separate
n-p
types of diseases ip the regions tn npvoi
control them and to give recommendations on organizing and coots ol medical service on the Gambella Plain terrl- tory.
It is with regret that we inform that it was imposslbl to organize additional studies on the issue under con— oideration and coverage of the epidemiological situation problem remains at the level of the first stage of the blaster Plan elaboration.4,5.     Water
of  Populated
areas and agricultural
pro.i ects
This section was not considered in the Master Plan
vroiccT X
Preliminary Report.
* Work on this section is being carried out in accor— 
ce  with the requirements of the program. Both surface
uid ground water are used for water supply depending on existing conditions.
Norms of water consumption and water supply and
g ev/age systems adopted for the Master Plan are given
below.
4.5.1.       Norms of water consumption
To determine the volumes of water consumption and water disposal for all kinds of water consumers the fol lowing norms of water consumption and disposal are adopted which correspond to the types of housing (see table T).
Table 1
Norms litre/day/head
Nos Types of housing and other Water con- Water
item
facilities
_       _ 
1.  Houses equipped with internal water piping and sewage without baths
2.
3.
4.
5.
6.
7.
Houses equipped with water pi ping, sewerage and baths with 
gas and solid fuel heaters
Houses equipped with internal water piping, sewerage and sys tem of centralized water heating 
'7ater consumption from water point public and induvidual toilets Consumption from local sources using domestic water filters Catering of greenery and solid surfaces
Rouses of communal use, health, 
125 - 160
160 - 230
230 - 350
s
30 - 50 20 - 30
_ disposal
125 -   160
160 -  230
230 -  350
25
-
20 - 50                      —
° °PPing 
n
an g foog centres
80-100
25I
r-.' • ' *
- ■
19.
w
r agricu
,a{
er
Lulre”ents
f°r
Hural products processing factories
tion norms are taken in accordance with the of the technological equipment. Water 0 fire fighting and probable number of sim i , are taken depending on the number of n» 
..uieous fires
tiie  settlements
... Wien there are less than 500 people
o21 e fire with \._.
" ore than 500 people -  101/sec.
water consumption of 5Vsec, when there '
one fire with water consumption
of
taken as follows:
V.
a ter consumption norms for
an
-f
m
S.»o denomination of consumers
7. Cattle
2, Sheep, goats 3, Poultry
a 3 ahd poultry are
Table 2
'^ater consumption norms' 1/ day/head
60 - 80 6-10
1 - 1.25
4.5.2.   ’hater supply and sewage systems
To provide the population and agricultural processing factories the following water supply and sewage systems are adopted.
4.5.2. 1
Irotn the surface
•■ater is delivered to Jity pipeline, then it -- -
re
■Vater supply systems
source (river, canal, reservoir)
the bank-side well through the gra- is punped to the purification works
Mainly supplied in full assembly by the manufacturers and °? rating in the open air), after purification water of
e
s
Voi^^"6 con<^^^1-on i  delivered into reserve tanks (reser-
rS ’ Wa't'er towers) and then it is supplied into the dis-
^tion system of a settlement.
■ Ve-^ r°‘a ^lXe ground  source water is pumped  from the bore-
(reg  ?
e
lie 1-P of a submersible putnp into reserve tanks
rv ° 3, water towers) and then into the distribution
ir20.
, p1l of a , .,,,1-er is not upto the standard it is
s
etti°men'U
sJ- jfgr° .t ried by traditional methods, X anally pul
sewage fro™ Houses,
industrial buildings and fa-
P»rincaMon W°rlC3
ell  i uv gravity to the sewage station,
1
d4
4«clhi*6tweco pr   l °  essure tunnels          n
Lt plant (air tank)
After
and public toilets is
from where it      is      delivered      to      a      oom- that sewage is delivered
, nto a contact reservoir ^charged by gravity to
authorities (river,
where it in disinfected and
the       places       slotted       by       the       sani- etc.).
nap ply, .for mturnl pastures
To supply water for natural pastures it Lrj envi
saged. to construct a network of water points in order to provide cattle for normal travelling distances with re
gard to fodder capacities of the pastures.
To mechanize water raising at the pastures It is recoinmended, alongside with hand pumps, nolary water raising installations with individual energy sources <bn 
toe basis of photoelements.
•^ater points should comprise: water intake (pit --^1    or    borewell    with    the    depth    down    to    30m)
v/1.th water
Rising equipment,
^-*7 and watering *** contributed from
reservoir with storage capacity per
site with drinking troughs. The works monolith reinforced concrete.
4. >. 4      Cap it al investments indices of specific capital invest-
thfa ' '-n'‘rz'mined on the basic of coots indices of -*'> irrigation project.
*isf*l*21
4.6.    Section "Water Supply Analysis]]. (Water Resources Planning)
The water supply analyses consider the possibilities of water supply of all measures on agricultural (including irrigation), industrial and hydropower development of
the Baro-Akobo Valley, envisaged by the Master Plan and determine the degree of utilization of the available
water resources.
The following main propositions are taken as a basis
to carry out the water supply analyses for the Pinal
Draft Report:
4.6.1.      The annual reservoir water discharge is deter mined by adopted method, taken for calculated probability and given level marks of the reservoir: PRL and DSL.
4.6.2.      The calculated probabilities of the annual water discharge are taken as follows:
irrigation hydropower
- 80%;
- 90%;
sanitary water flow and water supply 
-  are
satisfied completely under            any water         content.
4.6.3. Environmental water flow is taken with 
coefficient 0.75 of the mean monthly water discharge of
95% probability. The volume of environmental water flow
is kept through June till November. At the rest period 
of the year the water discharge in the river is kept at
the sanitary level.
4.6.4.      Sanitary water discharge in the river is taken equal to minimum mean monthly water discharge of 95% probability.
4.6.5.     Ensured productive capacity of the hydropower station is detrmined by 90% probability.
4.6.6.     Beyond the calculated probability in the years of low water it is allowed to decrease water consumption for irrigation by 20%, e.g. the desirable value during 
the scarce period is satisfied only by 80%.
4.6.7.     Environmental water flow from reservoir at22
the control section is given not less than 1 time in
4 years.
4.6.8.       To characterise water resources utilization the prepared papers give the analyses of monthly time intervals in the 80% and 90% probabilities. Chronological charts of regulated river flow and reservoir levels are given for low water content - 90%, medium and high water content - 10%.
4.6.9.       Annual electric power production of hydro power station is determined by 3 years:
high water me dium low water
- 10%
- 90%
During multi-year regulation of river flow the calculated annual water discharge is as follows:
hydro power irrigation 
- 90%
- 80%.
Environmental water flow is provided during high water flow.
4.6.10.        While calculating the cascade regulation of river flow (two water reservoirs), the volume of environmental water flow as a rule is kept at the cross
section of the downstream hydroworks.
4.6.11.       Navigation water flow is not specially pro vided.
4.6.12.       Because of small evaporation losses from the reservoir, the value of losses is determined by the layer
losses, which correspond to the average climate con ditions.
4.6.13.        All water supply analyses are being made according to the USSR methods.
4.7, Flood Control
4.7.1.  Due to special distribution of precipitations over a year and peculiar relief considerable areas of Gambella Plain are flooded during the rainy season mostly in it3 western part.
The area of flooded lands and the flood period vary23
and. depend, on the amount of precipitations and the nature
of flood along the rivers. In the year of 1988 which con
stituted approximately 2% probability of the flow amount
the area under flood was about I.Omln.ha.
4.7*2. According to the observations flooding takes
place for two reasons:
-   overflow of rivers and flooding of adjacent areas;
-   concentration of precipitation waters on the
surface caused by low slopes, high unevenness factor of the
surface and low filtration properties of soils and 
grounds.
The plan of location of lands flooded due to the
above mentioned reasons and their area at different preci
pitation probability are being studied and will be de
picted on 1:200000 maps.
4.7.3.           The     considered     area     subjected     to     flooding     at regular     intervals     is     mainly     used     as     a     pasture     for     cattle the number of which is about 320 thousand.
4.7.4.       The total area used for crops is about
4.5  thousand ha.
4.7.5.       The area which is annually flooded does not contain expensive capital structures. The structures
situated here are mainly tukuls in which local population 
lives,lairs and shelters for the livestock.
In 1988 a part of Gambella was flooded, Itang was comp letely under flood.
4.7.6.       When considering the effect of flood on the area subjected to flooding one comes to the conclusion 
that this fenomenon can not be treated as single-valued. 
It has positive and negative consequences. Annual flooding of considerable areas of the plain western part creates
a peculiar ecological balance due to which the plain has fodder pastures all year round, which enables to keep cattle in considerable quantities.
According to the observations the most productive and most used pastures of the plain are those which are subjected to more intensive flooding by the river floods. 
The areas which are underflooded by precipitationsonly and not influenced by the river overflow, have
vegetation which is less productive from the point of
view of fodder resources.
Having the observation data only for one year, it
is impossible to evaluate completely to what extent the
productivity of the plain western part pastures will
change in case water from the river; overflow does not
enter the plain, i'pr this purpose the appropriate multi
year experiment should be arranged.
Nevertheless, according to observations absence of
flooding makes it impossible to use pastures all year
round.
4.7.7.      faster j?lan presents a brief consideration for
possibility to determine the damage inflicted by the
river overflooding in terms of money.
4.7.8.         The    damage    of    pasture    overflooding    by    itself cannot    be    estimated    in    terras    of    money,    because    the    floo ding    makes    the    pastures    more    productive    and    thus    it    can not be considered as a disaster.
The second reason, which does not allow to estimate
the damage, is the fact that there were no capital in
vestments to the overflooded pastures. That is why it is impossible to estimate the pasture damages.
4.7.9.    l>ue to prolonged overflooding in 1988 all
4.5        thousand ha of cereal crops, located on different flooded territories, were damaged.
Taking into account the average yield crop - 14 cent
ners per ha and average price of 1 ton of cereals -
355 birr, the damage is estimated as 2.2 mln.birr. If
these cereal losses are compensated by delivery the same emount of cereals from Addis Ababa, in this case the
price of cereals due to transportation expenditures will
be approximately twice as much and will be about 4 -
4.5        mln.birr.
4.7.10.  The structures,which are built and may have the price, are mainly tukuls in which local population lives. 
As a rule these tukuls are located along the rivers banks. In practice, gradual flood increasing permits the
population to move with property and livestock (if any)\
25
\
'■ fifom flooded areas to more high lands. Fhoded tukuls
I; ]
atfe not damaged and when flood goes off, these tukuls
e used, again. Thus, according to the tradition, the temporary flooding of tukuls cannot be estimated as a
damage in terms of money.
4.7.11. The Master Plan Study Team has no infor-
mation about the damage inflicted by the 1988 flood to Gambella and Itang.
As a result of observations and inquiries it is determined that there are no destructions with signifi cant cost in Gambella and Itang.
However, as a result of the flood, there are very difficult social conditions for the population: trans portation problems, food supply, electric power supply^ medical service and living conditions. The situation 
demands organization of the flood protection.
4.7.12.    The main flood protection measures, taken by the Master Plan Study Team, are given below.
4.7.12.1.     The possibility to transform by the upper reservoirs the floods of 1% and 10% probability which 
run to the lower reaches of the Baro, Alwero and Gilo rivers is being considered.
The possibility to decrease the floods and allow
the flood waters run along the main bed without flooding the near-by areas is being analysed.
As a result of the preliminary consideration it is determined that organization of the upper water reser voirs (at the expence of decreasing electric power pro
duction at them) can provide flood runoff at certain river sections without flooding the river banks.
At the same time the water reservoirs can not pro vide flood control, which guarantees water discharge along the whole length of the rivers.
The situation is aggravated by considerable back waters of the Pibor and Sobat rivers. The possibility of their regulation is not considered by the Master Plan Study Team.26
does not consider flood protection of each spot.
The possibility of their flood protection will be considered while analysing regulation capacities of
water reservoirs.
4.7.12.3.        Engineering measures are being developed to protect Gambella and Itang from flooding. These mea
sures include: weep drains, protection embankments drainage pump stations etc.
4.7.12.4.        Calculations, bases and layouts of flood control measures will be given in the Draft Final Re
port.
4.7.12.5.   Recommendations on flood control of the projects, designed by the Master Plan (if such flood 
control is necessary), will be also given in the Draft Final Report.27.
4.8. Concerning estimation of the
volume3 of capital investment3
In the minutes of the Technical Committee meeting on discussion of the Master Plan Preliminary Report it was suggested to update the volumes of capital invest ments for the construction of the projects envisaged by 
the Master Plan in accordance with the prices of 1988, With this aim the Customer by the letter dated 
October 25, 1933 informed the Master Plan Project Team of the annual inflation rates which comprise:
internal inflation rate
external inflation rate
- 10%
- 9%
In order to update capital investments in compliance with 1988 prices the Master Plan is using the prices
of 1985 (.submitted by the Customer for calculations of the Alwero-Irrigation Project) taking into account the above-mentioned annual inflation rates.
Because of the fact that it is difficult to estimate the separate effects which internal and external inflation rates have on the construction costs of the projects
envisaged by the Master Plan, the team has adopted annual inflation rate as 9-5%.
With the aim of compatibility the volumes of ca pital investments for all the levels of master Plan 
calculations are taken as corresponding to the prices of 1938.'iy

Summery

Prepared by: All Union Export and Import Corporation (V/O "SELKH02PROMEXPORT")

Year: 1989

Location: Gambella Plain, Ethiopia

1. Introduction

The Baro-Akobo Basin Master Plan Study was conducted to develop a comprehensive plan for water and land resource utilization in the Gambella Plain of Ethiopia. The study was carried out in two stages, with this document representing information for the Technical Committee on major problems and development at the second stage of work.

2. Survey Work

Additional topo-geodetic, geological, and project materials were studied, including:

Aerial photo materials acquisition and study
Helicopter surveys of inaccessible areas
Modern technology for natural conditions survey

The study produced specialized maps at 1:200,000 scale covering geology, hydrology, soils, geobotany, and hydrometeorology.

3. Agricultural Development Concepts

General Aim

Growth of social and economic development based on utilization of natural and manpower resources.

Program "Minimum"

Two alternatives were proposed:

Alternative	Key Features	Projected Output by 2010
Priority Irrigation Development	Existing arable land: 26.6k ha New irrigated land: 23.9k ha New rainfed land: 10k ha 9 state farms	Grain: 66.4k tons Raw cotton: 40.7k tons Fruits: 16.6k tons
Rain-fed Alternative	Total planting area: 108.3k ha 97.9k ha rainfed lands Higher manpower requirement	Grain: 67.4k tons Raw cotton: 43.4k tons Fruits: 4.5k tons

Program "Maximum"

Additional development including:

Sugar cane complex (18k ha, 180-190k tons sugar annually)
Alcohol and distillery factories
Increased export production

4. Livestock Development

Central Non-flooded Area

Dairy-oriented animal farms with state farms
Experimental farms with local "Abigar" breed
Poultry factory (60k hens, 12M eggs annually)

Western Flooded Area

All-weather road construction
Agricultural associations (300-400 families each)
Pasture management improvements
No recommended changes to traditional cattle breeds

5. Industrial Development

Ginnery (40-43k tons raw cotton, 3M birr)
Oil refinery (23-25k tons seeds, 1.5M birr)
Potential dairy factory
Bread-baking factory (8t/day, 830k birr)
Sugar complex under "Maximum" program

6. Water Resources and Irrigation

Irrigation system efficiency: 0.60-0.65
Design year: 80% probability (FAO recommendations)
Maximum water lift height: 50m
Flood protection walls for 10% flood probability
Detailed management structures proposed

7. Wildlife Conservation

Revised boundaries for Gambella National Park (719k ha total)
Experimental farm for big antelopes proposed
Potential for crocodile and ostrich farms
Nature reserve in southwest deemed inexpedient

8. Flood Control

Key observations and recommendations:

Annual flooding affects up to 1M ha in wet years
Flooding has both positive (pasture productivity) and negative effects
1988 flood damage to crops estimated at 2.2M birr
Protection measures proposed for Gambella and Itang
Upper reservoirs may help control some flooding

9. Capital Investments

Cost estimates updated to 1988 prices using 9.5% annual inflation rate (based on 1985 Alwero Project prices).