HIE FEDERAL DEMOCRATIC REPUBLIC OF ETHIOPIA
MINISTRY OF WATER RESOURCES ADDENDUM TO INCEPTION REPORT
FOR
THE FEASIBILITY STUDY OF THE BARO 1 AND BARO 2 HYDROPOWER PROJECTS
DESK STUDY ON GENJI DIVERSION ALT. C II
October 2004
NORPLAN GS Norconsult «£♦
LAHMEYER
INTERNATIONALJI
3
5Federal Democratic Republic of Elhiopia - Ministry of Water Resources Desk study on Genji Diversion Alt C II
Feasibility Study of Baro 1 and 2 Hydropower Projects____________________ _ ___________ _____________ Pago i
TABLE OF CONTENTS
table of contents................. .......... ..................... .......... ...................................... .......... I
LIST OF FIGURES
1 INTRODUCTION
II
2
RESULTS AND CONCLUSIONS OF THE DESK STUDY .............
2.1     Recommendation..^....... ........ .........
22      Summary of results................ ....... ......... ...... .
23      Brief description of the various C II Options
2.3.1  Oplfon 1....................... .........................................
2.4
Option 2.... ................. ............ ................
23.2
2.3.3  Option 3...,...... ............................... ..............
2.3  4 Increasing the volume of Baro i reservoir.............
Basis for cost and energy production data
24 1   Total comparativa costs for Bam 1-2.............. .............................................. ...... ...............,
2.4.2  Cost basis for the options.............................................. ......... .—................. .......... .......... .
24.3   Comparative energy production figures for Baro 1-2.................................. ..................... ..
24 4
2.4.5
Summary of major cost itfiffllS......
...................
Ener gy production analysis for the a pbems ...................... .................. ...................... .....
21
,*.*2-1
... 2-2
2-3
23
2-3
-.2-4
....2-4
...2-5
....2-5
... 2-5
....2-8
....2-fl ..2-10
3 GEOLOGICAL CONDITIONS. RELATIVE TO BARO 1-2 ,.
4 HYDROLOGICAL CONDITIONS. RELATIVE TO BARO 1-2
4-1
41
Scope of investigations...
. .4-1
4.2
4.3
Rainfall............. ......... ..........
Streamflow...........................
Evaporation
4-2
4-2
44
.... 4 4
45
4.6
4.7
48
Maximum rainfall...... ..........
r
.... 4-5
Floods............ ,....................
Sediments ....................
Conclusions ....... .................
.... 4-5
— k-.
.... 4-6
!
.... 4-6
5 ENVIRONMENTAL ASSESSMENT. RELATIVE TO BARO 1-2..................... ....................................... 5-1
5.1 Environmental and land Use Descriptions of the Sites................. *..................... ........................ „.......5-2
5 2 Socio-Economic Considerations.............................................. .................................... ................... 5-6
5.3 Conclusions - Environmental Study ........................ ............................................................. ... ........... 5.7
Qdobw 20OA*
i iFederal Democratic Republic of Ethiopia - Ministry of Water Resources Desk study on Genji Diversion Ait C II Feasibility Study of Bgrp 1 and 2 Hydropower Projects________ __________ _ ______________________ Page il
LIST OF FIGURES
Figure 1-1 Alternative C II. Option V Schematic layout................................. ............................ ... 1-1
Figure 1-2 Alternative C II, Option 1. Layout on map............ ............... ..................,...............................t-2
Figure 2-1 Unit costs for RCC dams. (For preliminary estimates).......................................................   2-6
Figure 2-2 Total El-Mech costs for Bare 1 from Pre-feasi bilily Study)...................................................2-7
Figure 2-3 Total El-Mech costs for Baro 2 (from Pre-Feasibilily Study............
...2-8
Figure 4-1 Hydrological sketch map of the Baro project area............... ...................................... . 4-1
F'gure 4*2 DimensFonless flow-duration curves for Sor and Baro rivers................................................ 4-4
Figure 4-3 Peak flood discharge relationships........................... ........... .................. ........... ............... . . 4-5
Figure 5-1: Location of the proposed reservoir sites .............. ........................................................ . 5-2
Figure 5-2: Baro I al flood level of 1520m....................... ........ .............................................. ............ .....5-4
Figure 5-3: Baro 2 at flood level of 1320m .................... .— ...................................................... . 5-5
Figure 5-4. Genji at flood level of 1350m .................. .................... ........................ ............................. 5-6
LIST OF TABLES
Table 2-1 Results from the Desk Study, with comparative figures for Baro 1-2 ..................................... 2-2
Table 2-2 Summary of major cost items for the various options ........................................................... . 2-9
Table 4-1 Rainfall station data. ....... .............................................................. ......................... ...............4’2
Table 4-2 Streamflow station data ........ ................................................................... a.... ....................... 4-3
Table 4-3 Predicted peak flood discharges (n?/s)....................................... .......................... ............ ...4-6
Table 5-1; Summary or impacts and concerns Baro! ........ ......................... ...... .......................... . ......... 5-3
Table 5-2: Summary of impacts and concerns Baro 2................................... ............................. t..... ..... 5-3
Table 5-3: Summary of impacts and concerns Genji................ ............... ,............. . ,............................ 5-4
Octode*’ 2004p
p
p
9F Qdsral Dornocmtic RcoutHic of Ethiopia - Ministry of Waler Resources Desk study on Gonjl Diveraioii Alt C ll Feasibility Study oi Barg 1 and 2 Hydropower Projects _                ________ __________ ________Pagel-l
1
INTRODUCTION
In Section 5.8 of lhe Inception Report for the Feasibility Study on the Bara Hydropower Projects, several alternatives (or utilisation of flow in the neighbouring Genji River were discussed. One alternative, called Alternative A, was recommended for further study in parallel with the Feasibility  Study  Some alternatives  were discarded, and it was decided that one alternative, named Genji Diversion Alternative C II, be subject to study in more detail before any recommendation be made.
Alternative C II, as presented in lhe Feasibility Study, is schematically illustrated in Figure 1-1. In lhe following, it is called All C II Option 1.
Figure 1-2 shows the layout on a map of the area.
2004
figure A/ferna/ive C Opfwn f. Schemabc fayoutFederal Democratic Republic of Ethiopia - Ministry of Water Resources feasibility Study of Baro 1 and 2 Hydropower Projects
Desk study on Genji Diversion Art C II
_____________________________ Pape 1-2
Figure 1-2 Alternative CII, Option 1 Layout on map
October 2004z HI
1 9 n
0 c
Mr
9H
IM
MFntJeral Democratic Republic d? Ethiopia - Ministry of ’iVater Resources Desk sludy on Genji Orvers-ioo Ait C II FcJialbiMy Study of Baro 1 and 2 Hydropower Propels ________ _______ ___ _______ ____ __________ Page S3
All. C II, Option 1 would transfer flow from '.he Bare 1 reservoir to a reservoir behind a high dam on the Genji river. The Baro 2 develop ment would be discarded and substituted by a hydropower develop ment direcUy from the Genji Dam, along the left side of the Genji and Baro rivers to a tailrace tunnel outlet near the confluence the Baro- Fani rivers This new plant would be able to exploit a live reservov volume behind the Genji dam that is equal to or larger than the Baro
1 reservoir volume, with equal or less extent of inundation of rain for est. The Baro 1 power plant would be shifted to develop the head be tween a low Baro 1 dam and Genji, possibty as a run-of-river plant with daily peaking only.
The main results and conclusions of the sludy of Option 1 and other alternatives are given in Section 2. The remaining sections describe in more detail the methodology used for assessing geological and hydrological conditions, environmental impact, costs and energy pro duction for the options  of Alt C It and comparing them with I he scheme presented in the Pre-feasibility Study,
October 2004Fodarai Democratic Republic of Ethiopia - Ministry of Water Resources Desk study on Genji Diversion AH C i| Feasibility Study of Baro t and 2 Hydropower Propels__________________________________________Paga2-1
2                            RESULTS AND CONCLUSIONS OF THE DESK STUDY
2.1
Recommendation
It is recommended that the Feasibility Study concentrate on the Baro 1-2 scheme, including study of Genji Diversion Alternative A.
The Genji diversion Ait. C II should not be subject tD further study at the present time.
li appears not possible to establish a scheme so that the energy pro duction of Baro 1-2 is maintained and, at the same time, reducing the environmental impact.
Larger reservoirs than assumed for Ait C li Option 1 wtH imply signifi cant increase in firm and total energy, as shown in Options 2 and 3. But if such alternatives are contemplated at aii, the best solution may be to maintain the Baro 1-2 scheme with increased reservoir volume at Baro 1, as demonstrated tn column F of Table 2-1.
Table 2-1 on page 2-2 gives a summary of the main results of the desk study, including comparative figures for the Baro 1-2 scheme
The specific construction cost, expressed as construction cost per kWh of average annual energy, shows a remarkably small variation. Considering lhe uncertainties involved in estimates of costs and of energy production, lhe schemes are practically equal as regard spe cific construction costs Selection of scheme should mainly be made with a view to potential for dry season energy production and envi ronmental impact.
October 2004M
■
HI I
E| to
M
H
to to to to to to to [hr—m
Federal Democratic Republic of Ethiopia - Ministry at Water Resources Desk study on Gttn|i Diversion All C II
Feasibility Study ol Baro 1 and ? Hydropower Projects_____________ _ _________ ______ Page_________________________ _____ ____________ Pa9°
2.2
Summary of results
A
El
C
□
E
1- .
5HEME COMPANION
GbnJI C II, Qfrtton
1
G-onJI C 1, Option
3
G*njl C 1, Optkon
3
Comp4Mt>v« <1*14
Prv'fajiilblltty Khmn
t nil nd mJ JfUra 1 ub*«d
Id 94 1536|
Upper
HP*
Ltmrar
HPP
Upp«r
HIV
Lthrtl
HPP
UWwt
tlPP
I.-M4
HP*3
furol
ftartiH
EK4TO I ♦
B*o II
Cjpac4y, MW
IW
576
11X1  :
570
120
510
170
4S3
IM
483
HvmI
120
515
IDA
MS
175
57*
505
300
505
turbria ft?*, n i't
fS
nci
130
113
130
ao
11 l
113
113
113
113
Lh>« raitochlf *a»t>irtt mlMIwi m
(
1
(■ffmlljl
•50
440
MO
|»nuM)
1050
4fl0
s»
i«ro4ll)
Inuthlafvd              lun
31
S'j
40
26
M
Ltnylh al ncce*l roadi, krri
40
40
40
36
3d
Tatjl flrviua* dMirJQB produdMXi
J 200
40W
5100
3100
3400
Production during fl dnail month*, GWl
itoo
3XU
2050
1550
225C
1   ui*l   Lnmp» Hh .e   canstfucaan   casti,   «ma   trwvnr*wor
r,
i^’wonmenlal costs. USD n*illwi
M
41}
2tt
412
1Q1
443
■
m
247
376
2<A
T oUM ownnarwllirt COCA true bon otMts Far hgh  tow! *l*r* tf»Cl Uammlinan, USD m JI ten
SOS
617
5<G
445
b?3
Trurmniivi-kjn co4ts. MUmcd U5t>
125
12S
128
126
126
Woflitan flVBjiurn asxj^’c-J JSO rnttien
5
W
7
4
5
T«fli cflni(iarjfrYW costs USD mlixn
642
755
661
STS
iW
5p*c*e carrtiU'izJcr ceC USD&Wh
0W
U IB
052
D.1B
■3 19
Effect of hncludbn^ G*nji ^Wlion AM A :
M|i4W bU                        pradwetor. GWH *)
Al'LBhed fMWwcfcon Ojn^g fl drl«| rnurilfii
lncrww-8 *1 LjumpB*attvB cnnslmci-ari «|L USD million kenuw. b-jritrnltBon goeLs, auumtd, USD million
n tniugacign cotta, a»tiffl«d USD million
(Nol xwl«vanl|
(Nol ratavwnll
<Moi rdovanlj
M5D
IflOO
1M
1
1
4040
7$Q0
IM
t
1
"□U a^jiled wifjralM ccit, USD rMlQO
713
fv?
Sp*CJ »C ents'fly ^i»1, IfSU-VWfl
r
I.
1
0 1o
o 20
Costs  ol Bare 1 and 2 have been increased slightly, rotative to the figures  in the Pre-fsastolity  Study, as  result of a review of the previous  cost estimates  with respect to rock  support costs  and a few corrections. The cast basis  of the Pro-Feasibility  study  has been maintained, however, it has oct boon adjusted to 2004 level
Tabio 2-1 Results from the Desk Study, with comparative figures for Baro 1-2
October 2004Forinrnl pnmccralic Republic of Ethiopia - Ministry of Water Resources Desk study on Genji Diversion Alt C II
Feasibility Study of Baro 1 and 2 Hydra power Projects 
Page 2-3
2.3
Brief description of the various C II Options
2.3.1                            Option 1
C  II  Option  1  is  illustrated  schematically in  Figure  1-1  and  on  a 50 000 map in Figure 1-2 II comprises an approximately 120 m high RCC dam on the Genp river, with crest elevation at 1340 masl. With regulation between elevations 134Q and 1300 masl, this creates a live reservoir of 650 million m , with a surface area of 31 km' .
a
A tentative tunnel alignment and powerhouse location for the Lower power plant is indicated The reservoir on Baro river is reduced to a daily peaking reservoir only. An RCC dam with crest level at elevation 1460 is located some 6.5 km upstream of the Baro 1 dam site. A ten tative tunnel alignment and powerhouse location for the Upper power plant is indicated.
Conclusion, with reference to Table 2-1. column B
Alt, C II, Option 1 gives only marginally higher energy production than Baro1-2. al higher construction cost. The soecific construction cost expressed as USD per kWh is also higher than for Baro 1-2. although these costs are more ore less equal in practice The environmental Impact of Option 2 appears to be slightly higher than for Baro 1-2, with slightly larger area of inundation and longer access roads.
The above conclusions are valid for Baro 1-2 without inclusion of Genji Diversion Alternative A. When that alternative is included, the companson is more unfavourable for Option 1, although difference is small. (Reference is made to the inception Report, Section 5 8.2, for description of Alternative A.)
Option 1 is, therefore, not recommended, since it does not fulfil the Intentions of reducing environmental impact and does not clearty in crease energy production.
Note The mam reason for trie modest gam in energy production is that the Genj> reservoir *s located at a lower level tnan the Baro 1 reservoir. A reser voir at Baro 1, with elevation 1505 masl level will produce energy over a head of some 670 m. while a reservoir at Genp. with elevation 1340 masl, will nave a maximum head ol some 505 m. Thus an increase in live reservoir volume from 460 million m3 to 650 million m3 is offset by a corresponding reduction in head.
2.3.2                            Option 2
Option 2 maintains the Genji reservoir at elevation 1340 and main tains also the Baro 1 dam and reservoir as it is in the Pre-feasibihty study at elevation 1505. This option has a total reservoir volume of 1130 million m3, and is dearly very unfavourable environmentally.
The objective of investigating this option, was to find whether energy production would increase Io such an extent that such added envi ronmental impact might be considered justified.
As might be expected, Option 2 is very favourable with respect to dry season energy and total energy production Firm energy will increase
0 :1c*er 2«H*
I
I! 81i I ,!
I'
Oil'
tai ilB tai tai tai tai tai taiFederal Democtallt: Republic of Ethiopia - Ministry nt Water Resources Desk study on Genji Diversion All C II Feasibility Study of Barg 1 and 2 Hydropower Projects__________________________________________ ^kio 2-4
significantly. Specific energy construction cost is lower than for the other options, but similar to Baro 1 -2.
Conclusion, with reference to Table 2-1. column C:
Option 2 would only be of interest if significant energy increase could justify more severe environmental impact. But if this is the case, then increase of reservoir size in the initial Baro!-2 scheme could yield similar result with less extent of inundation of rainforest, and shorter total length of access roads, shown in column F in Table 2-1.
Option 2 is. therefore, not recommended
2.3.3                             Options
In option 3, the Genji dam is raised 10 m to crest elevation 1350 to create a reservoir of some 1050 million m1, inundating an area of some 40 km?.The Baro 1 reservoir is reduced to a daily peaking res ervoir, as in Option 1.
The objective of this  option is  the same as  for Option 2, to see whether increase in energy production may justify more severe envi ronmental impact. The option cannot compete with Option 2 in any respect.
Conclusion, with reference to Table 2-1, column 0: Option 3 is not recommended.
2.3.4
increasing the volume of Bam 1 reservoir
Column F in Table 2-1 gives the result of an analysis of Baro 1-2 as suming that the Baro 1 dam is raised 15 m, giving a reservoir level at 1520 mask LRW is maintained at elevation 1485 This gives a live reservoir volume of 950 million m3 and an inundated area of 36 km2 according to the volume-reservoir curve in the Pre-feasibility Study.
When Genji diversion Alternative A is included in this scheme, annual energy production - firm and total - will be more or less equal to, or exceed, the production of Option 2. with less inundation of rain forest.
Comparative specific construction cost of annual average energy is 0.19 USDfkWh, the same as for Option 2,
Conclusion, re increasing volume of the Baro 1 reservoir
If it is considered that increased environmental impact can be justi fied provided sufficient increase In firm and total energy is obtained, then investigation of Baro 1-2 with increase of the Baro 1 reservoir should be given priority, before Option 2 described above
October 200*K 11 1Fcdera/ Democratic Republic of Elhlopia - Ministry of Water Resources Desk study an Genji Otvofsion All C II feasibility Study of Bare T and 2 Hydropower Projects______      _ ______________________________Page 2-5
2.4
Basis for cost and energy production data
2.4.1
Total comparative costs for Saro 1-2
The data used for Bare 1 and 2 in the comparison with the various C
Il options are shown in Table 2-1, column E, The cost figures are
higher than those given in lhe Pre-Feasibility report, for lhe following
reasons:
•    thorough review revealed that costs lor certain items had been
omitted in the detailed cost estrmales
•    rock support costs have been increased, as explained in Sec
tion 2.4.2
No other adjustments have been made relative Io cosl estimates in
lhe Pre-Feasibility study, and the cost basis remains at 1990 level.
The sel-up rn that study has been used as basis for estimating the to
tal costs of lhe various oplions
It is underscored that lhe resulting total cost figures for Baro 1-2 are
for comparative use only They will most probably deviate from the fi
nal cosl figures that will be a result of the Feasibility design and cost
estimate.
2.4.2
Cosf basfs for the options
Detailed spreadsheets were developed for the Pre-Feasibility Study 
of Baro 1 and Baro 2 for use in quantity estimation of dams of various 
types and for cosl estimates. A large number of alternatives for dam
heights, reservoir volumes, installed capacities etc. was analysed.,
giving a good basis for comparative cost estimation of alternatives tor
Genji.
The methodology used for costing of major structural elements is de
scribed below
It is underscored that all costs are for comparative use only - they do
not necessarily reflect the costs that will result from the cost update
that will be performed in the course of the Feasibility Study.
Dams
The 50 000 map was used to select dam sites that appeared suitable,
and for drawing lhe topographic profiles of the sites.
The RCC dam type was selected for this study, both at the Upper and
Lower dam sites, because the spillway can be integrated in the dam
body. A rock Uli dam may have lower cost for lhe dam body, but re
quires a separate spillway. Unless the topographic conditions are fa
vourable far such a spillway, as was the case for Baro 1, total costs 
may easily be higher lor such dams.
The total volume of lhe RCC dam was calculated with the dam site
profile as basis, assuming an excavation depth of 7 m of soil over
burden and 3 m of nock for all cases.
□clobe? 2*504r9
gFederal Democratic Raputtilc of Ethiopia - Ministry or Waler Resources Desk study on G<in|i Diversion A»t C H
feasibility Study of Baro 1 and 2 Hydropower Projects___________________________________________________________ Pagc_ 26
From data in the Pre-feasrbility study, a graph could be produced
showing unit RCC dam costs - ail inclusive - based on total concrete
volume in the dam  as shown
r
in figure. As may be expected, unit
costs on this basis decreases with increasing dam volume.
UrtlS cwrtl RCC l3arn«
« (M»        2*0 LOO 4W000 «OOTO 850 (XC 1 05C DOQ 1 2W MM1 1 450 l)lX) 1 650 W
Dim vqJwvm, m3
Figure 2-1 Unit costs for RCC dams. (For preliminary estimates)
For the small RCC dams at the Upper dam site, a unit cost of 95 USD/m'1 has been used For the large RCC dams at the Lower dam site, a unit cost of 62 USD/m has been used
1
Tunnels
Tunnel cross sections were set to 6B m2 in the Pre-feasibility study, for maximum estimated flow of 113 m"’/s  This  corresponds  to a maximum velocity of approx, 1.7 m/s.
Some of the options investigated have different maximum flows, and in these cases the cross sections were determined based on a maxi mum velocity of approx. 1 8 m/s.
Net tunnelling costs were then established using the formula given in the prefeasibility study: T = 20‘A + BOO. where:
T - tunnel excavation cosl. USD/m
A - tunnel cross section. m:.
The Pre-Feasibility Study used assumptions for rock support costs lhat are deemed too optimistic  for Lhe present comparison of schemes, considering the meagre informalion on tunnel excavation conditions. An addition of 35% on net excavation costs has been used for establishing comparative costs of the Baro 1-2 scheme
Geological assessment of the area indicates that general conditions will be similar for the various alternatives, but the Genji (unnels will need additional strengthening at certain portions, as  explained m Section 3. Cost pr m waterway tunnels have therefore been assumed to be some 7,5% higher than for Baro, for comparative purposes.hta tai
*
wFederal Domocmlrc Republic of Ethiopia - Ministry of Water Resources Desk study an Geajl Diversion Alt C II
feasibility Study of Bare t and 2 Hydropower Projects_______________________ _______________________ _ __Pago_ 2-7
Various civil works
The lipper and Lower powerhouses will be fairly similar to the Baro 1 and 2 powerhouses, respectively. A small deviation in costs, within 10-20 %, has been used in order to cater for the effect of larger or smaller plant capacities, relative to Baro 1 and 2.
Costs of items that are not much affected by plant size have been maintained as in the Pre-feasibility Study
Length of access roads has been estimated based on preliminary alignments on the 50 000 map.
Areas for site clearing have been adjusted to reflect differences be tween options.
It is underscored that errors In adjustment of costs of general civil works items will be insignificant in relation to the magnitude of dam and tunnelling costs.
Note on general layout
The access tunnel to the powerhouse and the construction adits will be significantly longer for the Genji Lower power plant than for Baro 1. This is due to the topography and the requirements to rock cover for the powerstation and tunnels In addition to the relative increase in costs, this fact has also implications for the construction schedule. Since Genji Lower also has longer total lunnel length than Baro 1, construction time will be longer. Since the conclusion regarding Op tion 1 is negative for other reasons, no attempt has been made at this stage to quantify the difference in construction time.
Electromechanical items
Cost Data in the Pre-feasibility Study can be summarised in the graphs shown in Figure 2-2 and Figure 2-3 Total El-Mech costs for Baro 2 (from Pre-Feasibility Study for Baro 1 and Baro 2, respec tively.
Total El-Mech costs. Baro 1
Figure 2-2 Tota/ EFMech cosfs for Baro 1 from Pre-feasibility Study)
October 2004^23
22Z)      LEE3      LLUtFederal Domocraiic Reoublk: of Elhfopia - Ministry of Water Resources Desk study on Genii Diversion Al! C II
Feasibility Study of Banj 1 nod 2 Hydropower Projects___________________________________________ ________________ Page 2-8
Total El-Math costs, Baro 2
2.4.3
Figure 2-3 Total Ef-Mech casts for Baro 2 (from Pre-Feasibility Study
The graphs have been used tn establishing comparative costs for the options investigated, assuming that the number of units in Upper and Lower powerhouses are maintained as in Bare 1 and Baro 2 power houses, respectively.
The accuracy obtained by this method Is sufficient for the purpose of comparing of options, considering the large uncertainty margins gen erally involved.
A list of comparative costs for the major items is shown in Table 2-2,
Comparative energy production figures for Baro 1-2.
The Pre-Feasibility Report does not give details from the energy pro duction analysis. There are no tables or graphs showing results for each year or month, nor average values.
A simplified analysis  by  use of spreadsheets  has  therefore been made for the purpose of comparison only, using (I) the monthly runoff data for the years 1967 - 1996 as given in the Pre-Feasibility Study, Volume 4, Annex A, Table A.2 "Annual and monthly runoff at Baro 1 dam site in millions ma ’ and (il) an updated set of runoff data for comparison. The difference between lhe previous and updated set of data is small, and insignificant for comparative purposes. It may ap pear that the most recent series is slightly more favourable for Baro then the previous one. The aim of the analysis was to find average annual energy production and that part of the annual production that could be produced during the 8 driest months of lhe year for Baro 1- 2, in order to compare these values with energy production of lhe various options. For this purpose, it is not necessary to lake into ac count detailed variations in head loss, total head and unit efficiency factors. Mean values can be used, as is conventional in analyses at the present level of accuracy
Oclobnr 2004Federal Democratic Republic of Ethiopia - Ministry of Waler Resources Desk study on Genji Diversion All C II
Feasibility Study of Baro 1 and 2 Hydropower Projects 
Page
Page 2-9
2.4,4
Summary of major cost items
Dpi 1 lipper
BO itt’/B BO
MW
Opt 1 Lower 130   my/s
570 MW
Opt 2 llpp*r 113 m’/s
160MW
Opt 2 Lower 130m1/!
570 MW
Opt 3 Upper 80rt?/l
120MW
Opt 3 lower 113 mVs
510 MW
Bare 1 Adjusted 113m’/s
180 MW
Bara 2 Adjusted 113 m^s
483 MW
Jlem
Access Road*
S<te Clearing
Camp and Village
River Diversion
Dam
Pdww Intake and Waterway
Power House. Access Tunnel and Portal
Building
Switch Yard
4 200
1 005
9 000
987
3  174
16 973 4  1DD
255
5 asc 5 025
10 DOC
1 118
96  315
47 401
tO 287
331
4 200
1 340
9000
3 510
52 652
19 628
4 876
331
5 850
5 025
10 000
1 118
96   315
47 401
10 28/
331
4 200
1 005 9 fl CO
987
3  174
16 973
4 100
265
5  850
5 025
10 000
1 116
120 270
45 901
10 28?
331
3 935
4 523
9408
2 980
52 702
9 330
4 876
331
4 283
2 17S
10 874
708
14 80?;
34 827
11 561
480
Sum    Civil    Work*    (    excl.    kcmi     roads, site clearing and village
25 490
155 451
60 996
155 451
25 498
177 914
70 219
62 463
Mnorilems    and    Mobilisation,    22%    of    Civil rExd site cleaner and Infrastructure i
5 610
34 199
17 819
34 199
5610
39 141
15448
13 742
Total   Civil   Works   ,   incl   alto   clearing. Village, ate
45312
210 526
113 355
310 526
45 312
237 931
103 593
93 540
EAM ante
30™
110 000
45000
110 DOO
35 000
106 000
50 781
100 872j
Tola!     (A)     Construction     costs,     excJ Transmission and Environ menial costs
75312
320 526
156 355
320 525
80 312
343 931
154 374
194 412
fcrighioering    and    Supervision    0    8%Tctal    A Adminislratcn @ 4%Tcrtai A
CoriinQuncy a' 20% ol Cnnl & 10% at EAM
6 025
3012
12 062
25 042
12821
53 105
12668
6 334
27 171
25 642
12 821
53 IDS
6 425
3 212
12 562
27 514
13 757
58 '86
12350
6 175
25 797
15 553
/ 776
28 795
Total (C) Adminlatration?Eng Inoorlng
21 100
91 568
45 174
91 568
22 20D
99 458
44 322
52 125
Grand Total, axd- Transmission linos and
Environmental costs
96 412
412 094
204 529
412 094
1G2 512
443 388
193 696
246 536
Table 2-2 Summary of major cost items for the various options
Oclaber 2CC4Federal Democratic Republic of Ethiopia - Ministry of Water Rosoixces Desk study on Genji Diversion AH C II
Feasibility Study of Bang 1 and 2 Hydropower Projects____________________________________________ Page 2-10
2.4.5
An annual average energy production of approximately 3100 GWh was found for Baro 1-2 This corresponds reasonably well with the statement in the Pre-Feasibility Report that '‘firm energy"4 is 2700 GWH. Firm energy must necessarily be somewhat lower than aver age energy.
Note. Reference rs made to Section 5.7 in the Inception Report for Baro, re garding clarifications  with respect to the term ‘firm energy*, both as  regards its  calculation, its  actual magnitude for lhe present project and its  impact on project economy. A necessary  precondition for arriving al 2700 GWh as  an nual firm energy is that operation of Bare will be coordinated with operation of the entire interconnected system, as  was  done in the simulations  performed rn the Pre-Feasibifity  Study. For the present ourpose of comparing alterna tives. annual average and dry season average production will be sufficient as basis.
Energy production analysis for the options
For each option, the inflow data has been estimated by scaling the data for Baro i in direct proportion with catchment size. The viability of this method for the purpose of the present study has been con firmed by the investigations made by the Hydrologist, as referred to in Section 4. II is underscored that the figures arrived at for energy pro duction are sufficiently accurate for comparison of options, but they will not be identical to the results from more accurate simulation that will be performed in course of the study
Note. For all options, It is  possible to increase plant Installation and thereby increase nominal energy  production. It must be noted, however, that all such increase will stem from additional production in the wettest months  of the year only, when there supposedly  will be a surplus  in any  case. Dry  season production will nol be affected. This  Is  the main reason for limiting the In
stalled  capacity  to  80  m /s  for
a
the  plants  with  daily  peaking  reservoir  onfy.
Higher installation may  be feasible for planls  with □ major reservoir, because the capacity can be utilised during peak hours  also rn the dry season. Opti misation of turbine discharge will be done as part of the Feasibility Study.
moder 20041
f
I
i
a
fl
Fl
'■
M
M
3L
Rtretf&ral DnoiocralFc Republic ot Ethiopia Ministty of Water Resourres Desk study or Gr?nji Diversion Aft C II
Foas4bHity Study pl Baro 1 and 2 Hydropower Pip,eels ________________ ___ ____________________________P3ge yi
3
GEOLOGICAL  CONDITIONS,  RELATIVE  TO  BARO
1-2
Geological conditions for the various alternatives have been evalu ated on basis of existing topographical and geological informalion and by stereoscope interpretation of aerial photographs, In the stud ied All. C II, Oplion 1, the layout is prellminanly optimised with regard to the assumed ground conditions It is expected that the general ge ology and the general technical quality of the rock mass are more or fess lhe same for this alternative as for Baro 1 and Bare 2. The rock mass quality encountered In parts of lhe tunnels may be lower due to smaller depth below terrain. This may be lhe case in lhe upper part of (he upper tunnel, with some areas of expected small to moderate thickness of rock cover For the lower tunnel, the rock cover is ex pected to be moderate for lhe area of crossing of the Wesa River, with possible influence on need for rock support and leakage preven tion Lining may be needed for a portion of lhe tunnel in this area
For proving the feasibility of the tentative layout and for optimisation of lhe lunnels, information on actual depths to bedrock In some areas would be needed, by exploratory drilling, or by dn I lings in combi na I Ion with geophysical investigations. The above assessments are consid ered sufficient for (he present comparison of alternatives
It Is  concluded that somewhat larger rock  support quantities  and more grouting for leakage prevention would be expected for Alt C If lhan for Baro 1 and Baro 2.
October 2004m rjn
2—i         uznFederal Democratic Republic of Ethiopia - Ministry of Waler Resources
Feasibility Study of Baru I and 2 Hydropower ProjedsPaoe__________________________
Pijgc
4
4.1
HYDROLOGICAL CONDITIONS, RELATIVE TO
BARO 1-2
Scope of investigations
The scope of hydrological investigations relating io the present Desk Study comprised'
•     Collection  of  new  meteorological  and  hydrological  data  re corded in the recent period since conducting I he previous Pre feasibility study {1990), as well as data recorded in additional stations in the Baro region
•    Analysis and comparison of recent and new records with those available for the Prefeasibilrty study
•     Evaluation of hydrological conditions in the Baro region, and derivation of compatible senes and design parameters to be used in the present Desk Study
A hydrological sketch map on the Baro pro]oct area, showing relative locations of project! sites and measuring stations, is given in Figure 4-1
Baro Project Area
too
o Taiu
BARO-2
GENUI
if
i
/
a
____________ J
ftsrrfall quinra___________________ t QMCtwmnt botnaary
dam sites
'
Bmci main river
Gauging ateUani
Stosfwinfc
7.3 I—
346                    34 B.
Longhudt E
35 0 35 ?
35.4
35 6                 35 a                     36 Q
Figure 4-1 Hydrological sketch map of the Baro project area
October 20W0
W
0
B
0
flFederal Democrat ' Republic of E1hlop<a - Ministry of Water Resources Desk study on Gen|i Diversion Alt C II
Feasibility Study of Bare 1 and 2 Hydropower Projects _______________________________________________________________ Page 4-2
4.2
Rainfall
A  number  of  new  and  addition  rainfall  data  were  obtained  from NMSA  Details  of  the  most  relevant  stations  located  in  and  near  to lhe Baro river basm, for which records were made available generally up to 2002 or 2003. are shown in Table 4-1.
In order to compare lhe spatial variation of rainfall on a compatible basis, lhe historical records were lentalively fllled-in and extended by correlation over a 37-year selected base period 1967-2003. As  can be appreciated, the highest recorded rainfall occurs  al Masha, lo cated al elevation 2250 m a.s.l. in the centre of the Baro project area. The mean annual value here, exceeding 2300 mm. corresponds  to some of the highest rainfall recorded in the country. At lower eleva tions, and in the river valleys downstream, annual rainfall diminishes to 2000mm and less. Al the dam site elevalion, around 1500 m a.s.l., annual rainfall Is expecled to be aboul 1700 mm.
Station
latitude
N
Deg M»n
Longitude
E
Deg Mln
Elevation (m a.s.l)
Histone
Mean
(mm/a)
Period
Compl.
years
I Extended Mean
(mm/a)
Bure
Gora
Masha
MeMu Hospital
Uka
Tepi
Gambela
0 17
89
7 44
8 18
8     10
7     12
8     15
35 6
35 32
35 28
35 35
35    24
35    25
34     35
1250
2002
2250
1620
1800
1100
450
1341
2147
2311
1774
1929
1574
1256
1975-2003
1952-2002!
1975-2002
1967-2002
1977-2003
1901-2003
1997-1992
17
47
17
25
6
15
01
1374
2045
2326
1783
1978
1571
==
Table 4-1 Rainfall station data
4.3
Streamflow
New and additional streamflow data from slat ions  located on the Baro. Geba and Sor rivers and tributaries were obtained directly from the Hydrology Department of MoWR.
Station details and record summary statistics are given in Table 4-2
Octotie* 20049
■
Pi
I
0
R
Hl
n
H
■I
■Fndfiraf Democratic Republic of Ethiopia Minis Iry of Waler Resources Desk study an Genji Diversion All C H
Feasibility Study of Bare i and 2 Hydropower Projects_____________________________________ _____________ _______________ Page 4-3
Station
L«fch<LM5i* N Mlii'
LortgilLKie
E
| nr .1 lArt
Elevation
i m a.j. |J
(km )
J
Historic Mean       RunoH (m7sj
COT.pl
years
Ettended Mean      Runoff
3             ■' mm.'a (m /s>
Baio lub-basln Bare Hr Masha Barn at G-arrtwi.i Baro Kt! Ila Mr Btiffl Genji Nr. Gecha GeVi sub-basin Sor Nr Metin GtJba hr. Sjpp<
Uka al Uka GumnwroNr Gore
7     34 9      15 a      14 7     34 fl      9 B     29 B     ID 0      TO
35      27
34      35
34      56
35     27
35     36
35      39
35 22
35 29
1050
420
aou
1650
1470
1150
1000
1700
1653
23461
4937
115
1622
3334
52 5
106
SI.7          1177
3B8.0          52! =              =■
4.90          1342
51 3          997 50 4          472 1 24           745 1 95          56-0
1990 2004 1967-1999
19B-6-1990
1990-2000
*967-2002
1976-2002
1900-2003
1M2 2001
9
27
0
3
32
4
16
15
601          1146 390 2         524
=                       ■a 5 34         1465
51.0         991 56.0          450
——
12
Table 4-2 Streamflow station data
Additional stations, not directly considered at the lime in the Prefea sibility  study, consisted of Baro near Masha and Genji near Gecha (located in the upper Baro and Genji catchments), as well the down stream station Baro Kella near Bure
Both  the  upper  catchment  stations  commenced  operation  in  1990
and thus now offer incomplete but up to date records of lhe respec tive rivers, which are of immediate interest to the current hydroelectric development studies. In the case of lhe Baro station a provision rat ing curve was established and an indicative flow series obtained, al though the measurements  and derived flow series  still need to be thoroughly verified. A similar situation exists at the Genji station, for which lhe most recent recordings since year 2000 are still being pre pared.
The downstream station Baro Kella operated discontinuously only for a short period between 1986 and 1990. Rehabilitation of this station is foreseen in the near future.
Furthermore, at all three mentioned locations, flow and sediment measurements  are currently  being carried out as  a formal activity within lhe present Feasibility  study. Analysis  and interpretation of these field measurements have not yet been undertaken.
As in the case of new rainfall data, lhe historical records were tenta tively  filled-in and extended by  correlation over a 37-year selected base period 1967-2003. Comparing the values of mean flow and an nual runoff depth it is apparent that runoff of lhe upper region of Baro river is slightly higher than that of lhe Sor river, measured at the key station near Metu.
Principally in view of total length and completeness of the neighbour ing Sor river record, this station record spanning 30 years from 1967 to 1996 was  taken as  a base for estimating inflow series  for both Geba and Baro river project sites in the Prefeasibility study. Allowing for adjustment considering respective catchment rainfall and area, the transposed Sor river series resulted in an annual runoff of about 1050mm at lhe Baro-1 site.
October 2004Federal Democraiw Republic of Elhiapla - Ministry of Waler Resources c ga wpility Study of Baro 1 and 2 Hydrapowr PrpiectsPage
___ Pa<3£ 4-4
Comparison of the Sor and Baro river records (or lhe extended period 1967-2003 is  shown in the graphs  of respective (dimensionless} monthly duration curves in Figure 4-2. The flatter profile of lhe Baro curve, together with the possibility of higher runoff than previously de termined, is  clearly  very  favourable for future hydroelectric  power generation.
As mentioned above, flow measurements and derived flow senes at the Bare station near Masha still need to be thoroughly verified be fore this station record can be accepted as a representative base se ries for current hydroelectric investigations.
In view of the completeness and proven reliability of the original Sor series it Is suggested to retain this series for lhe present Desk Study investigations, which involves solely comparison of alternative devel opment concepts
4.4
Figure 4-2 Dimensionless flow-duration curves for Sor and Bare rivers.
Evaporation
In lhe previous Prefeasibility study, monthly mean evaporation was estimated from meteorological data recorded at Gore, together with adjustment for reservoir elevation and incident rainfall. to arrive al a regional net evaporation profile for the Geba and Baro reservoirs
Up Io the present moment no significant additional or new meteoro logical data have been obtained. The previously estimated profile re mains, therefore, valid for lhe present application.
Oclo&w 2004I 01
4
5Federal Dontocratic Republic of Elh+qpia - Ministry d? Waler Resources
Feasibility Study d! Bare 1 and 2 Hydropower PrajocIsPage__________
Page 4-5
4.5
4.6
Maximum rainfall
Maximum daily ramfall recorded since 1996 at Gore is slightly lower (in regard to average and extreme values) than the previous full pe riod record covering the years  1952 to 1996. Probabilistic  return period estimates, including PMP. thus remain appropriately conserva tive.
Floods
A frequency analysis carried out on the annual maximum daily flow of Sore river near Metu, incorporating the latest recordings since 1996, indicated similar predicted probabilistic values to those obtained pre viously
Subsequently,  estimation  of  design  flood peaks at points of interest was carried applying the following steps:
•    Plot of Baro Prefeasibility estimates against catchment area
•    Derivation of Qp^T) - Area relationships for return periods TMO. 100, 1000 - years, and PMF
•    Application of lhese relalionships to estimate flood peaks at new points of interest.
The results of this procedure are presented in Figure 4-3 and Table 4 Baro Region
Figure 4-3 Peak flood discharge re/ationshjps
Oc sober 2004f
■ZZ2 lzzz] zn soa
11111Fodufal Democratic Republic of Ethiopia - Ministry of Water Resources Desk study on Genjl Diversion Alt C II FGHsiDflity Study gf Barg 1 and 2 Hydropower Projects_______ _________________ _____ _________ Page 4 5
Results of PFS
Area
[km’)
Return Period (years)
10
100
1000
PMF
Seta
Geba 1
Geba 2
Bare 1 & 2
559
1016
1576
2300
95
170
260
380
265
400
720
1040
345
610
915
1360
700
1215
1600
2250
New Points of Interest
Area
<km!)
Return Period (years)
10
100
1000
PMF
Bare 1 A 2
Guracha Transfer Point Guracha (Genji Confluence) Genji (Guracha Confluence) Genji Bara Confluence i
2300
190
245
1085
1355
380
35
44
181
225
1040
106
131
503
623
1300
151
181
640
708
2250
133
482
1220
1457
Fabte 4-3 Predated poafc flood d/scharges (mVsJ
4.7
4.8
Sediments
A value of specific sediment discharge of 132 T/km‘-year was de rived from 27 field measurements at Sar gauging station up lo 1996 in the Prefeasibility study.
Pending revision of these and other new sediment measurements in the region, as well as interpretation and incorporation of measure ments from the on-going field programme, this value can be used for present purposes.
Conclusions
The hydrological investigation carried out in this Desk Study involved, essentially, analysis and interpretation of new and additional data re corded in the most recent period up to 2003, in order Io compare previous results and predictions obtained in the Prefeasibility study for lhe Baro-1 and Baro-2 hydroelectric project sites.
The investigations  served to reinforce and extend the information base concerning hydrological conditions in lhe project region in re- gard to spatial and temporal variations of principal hydrological and meteorological parameters needed for hydroelectric project evalua tion,
Although a large amount of new river flow data were collected and analysed, it was considered loo early at lhe moment to deduce firm quantitative conclusions from these data, pending thorough verifica tion as well as interpretation and incorporation of lhe results of ongo ing field measurements.
For the present Desk Study, therefore, in which the purpose involves comparison of schemes through simplified analysis of relative energy production, the original flow data set given in the Prefeasibility study
October 2004*
I
8 I
3 0
!
■
k
1rorterai Oemo-c^atlc Republic or Ethwpia - Ministry o( Water Resources Desk study on Genji Diversion All C It
Feasibility Study of Sarp 1 and 2 Hydropewer Projects 
Pago 4-7
will be sufficient and adequate. On this basis the scaling of flow data according to catchment size for the various project sites will give con sistent and satisfactory  results in regard to evaluation and selection of alternative developments.
For the subsequent Feasibility  study investigations, concentrating on the finally selected option, all hydrological series and parameters will be refined and updated according to the methodology  presented in the Inception Report
frdobw 200*w
R
W
w
h
8
B
§
0
fl
Ml
■
MFederal Democratic Republic of Elh^pia - Ministry of Waler Resources Desk study on Genji Diversion AN C ll Feasibility Study of Baro 1 and 2 Hydropower Projects__________________ _______  Page 5-1
5
ENVIRONMENTAL ASSESSMENT, RELATIVE TO BARO 1-2
This desk assessment was earned out using remote sensing prior to a visit to the area. Contours for the flooding were generated from georeferenced 1:50,000 maps, on these maps the contours are at 20 m intervals thus some interpretation was needed and areas are not definitive. LandSat imagery (2001-2002) was used lo classify land use and lo examine the context of the proposed sites in relation to the surroundings. The mam classifications generated were:
•    Arable agriculture (cleared lands areas)
•    Coffee under forest canopy
•    Forest on shallow soils
•    Forest on deep soils
•    Forest on shallow groundwater (swampy conditions)
•    Wetlands and rivers
These classifications have not been verified
October 2«MFederal Democratic Republic of Ethiopia - Ministry of Water Resource* Desk study on Geqi Drversion AH C II Feasibility Study of Bare 1 and 2 Hydropower Projects______________________ __________________ Page 5-2
5.1
Environmental and land Use Descriptions of the Sites
Baro One The area of inundation for Baro 1 at the increased reser voir level was examined for the 1,520m upper flood level. At this ele vation. approximately 4.050 ha of land will be flooded The flooded area comprises mostly forest on shallow sotls with some deeper soils Relatively little although more than Genji, wetland will be flooded There was no observable settlement, arable agriculture or coffee planting activities identified for the area The reservoir will be ap proximately 17 km long and act as an effective barrier to movement between communities on either side. Figure 5-2 details the area
..1^.1- - ■         ■ A rin
3Federal Democrats Republic of Ethiopia - Ministry of Water Resources Desk study on G&nji Diversion All C 11 Feasibility Study erf Barg 1 and 2 Hydropower Projects_________________________ ___________ Page 5-3
Tabto 5- fr Summary of Impacts and concerns Barol
Sector
Impact
SeHtemonl and arable agriculture and access
NO Impact at present, the area he5IIH Io agncullural Dotenbal due to steep stopes and shalto# sells.
Access road to lhe construction site will effect between 3-4 km o( virgin forest The water body will reduce links between comm unities on &i1her side (east west movement}
Natural habirars
Largo area of virgin forest to be cleared I approximately 4,050 ha and riverine vegetation)
Bara Two; The area of Inundation for Bare 2 a! Ihe reservoir level of 1,320m upper flood level was examined. At this elevation, approxi mately 213ha of land will be flooded. The flooded area comprises mostly forest on shallow soils with a slightly higher proportion of deeper soils than Baro 1. Relatively little wetland will be flooded There were arable lands areas (approximately 8 ha) and coffee/new clearing in a further 10-11ha. The reservoir will be approximately 4 km long and is expected to limit harvesting of forest products by peo ple living to the north. Figure 5-3 details the reservoir area
Table 5-2: Summary of /mpacte and concerns Baro 2
Sector
Impact
SertlemtMit and arable agriculture and access
The area has low agricultural potential due lo steep slopes. Loss of approxt- matefy 8 ha of arable lands and 10-11 ha of coffee farming
The water body will reduce harvesting of forest products by communrties living north of ttie reservoir.
Natural habitats
About 172 ha area ol forest to be cleared.
Genjk The area of inundation far the larger Genji reservoir at a res ervoir level of 1,350m upper flood level was examined. At this eleva tion, approximately 3,840ha of land will be flooded. The flooded area comprises moslly forest on shallow and deep soils. Relatively little wetland will be flooded. There are arable lands areas (30-31 haj and coffee/new clearing in a further 53-54ha. The reservoir will be ap proximately 31 km long and will limit movement between communities on lhe opposite banks. Figure 5-4 details the reservoir area.
October zom—n      zmFederal Democfaiic Republic of Elhiopto - Ministry ol Water Resources Desk study on Gen*v Dwerson All C ii Feasibility Sliwly of Bars 1 and 2 Hydropower Projects _____________ _______________ Page 5-*
fabte 5-3 Summary of jmpac/s and concerns Genjr
Sector
Impact
Settlerneni and arable agricul ture and access
The area has low Io moderate agricultural potential although lim ited due to steep slopes Loss of approximately 30-31 ha of arable lands and a further 53-54 ha of coffee farming
The water body will links between communities living on opposite banks of the river
Natural habitats
About 3,260 ha area of forest will be cleared
Seftl*m«nt and Agriculture
Figure 5-2 Saro 1 at flood tevet of 7520mr-iHI t ■
J<J*Vrl' i t**T
’    **     *    »•
:
a
8
3
3
I
*Democratic RepuNio of Ethiopia - Ministry of Waler Resources Desk study on Genji Diversion .Art C II P&asjbilily Study of Baro 1 and 2 Hydropower Projects_______________________ _______ _ Page 5-5
Sett loment and Agriculture
!_ T
—?
1 ? KJk’™t<5r>
F/gwre 5-3. 8aro 2 af flood /eve/ o/ 1320mIII!!
rt ■
I 'U1
□3E3I                 1 1 1 1 IFeder.il Demwal>c Republic of Ethnpi® Ministry of Walei Resources Desk study on Genji Five iron AM C II Feasibility Study of Bare T and 2 Hydropower Projects ____  _______  _______  ______ _____ ___ Pay* 6-6
Settlement and Agriculture
K,hKMl* ’
r
Figure 5-4: Genji at flood level of 1350m
5.2
Socio-Economic Considerations
Socio-economic  considerations  would
not
bear
strongly  on
the
evaluation of the possible Genji diversion in the short-term Adopting the Genji diversion option would necessitate the temporary employ ment of more unskilled labour locally Thai could be counted as a minor advantage of the scheme.
Offsetting it, though, would be an increased likelihood of the ex change of communicable diseases between the local population and two site workforces, plus greater disturbance of lhe rainforest (at two sites) diminishing lhe sustainable utilisation of the forest in the long term Schemes leading to accelerated deforestation would inevitable have brief early advantages but longer term substantial disadvan tages in socio-economic terms
,«i -k.b k. m■■■«■■■■ I iI----------------------------- ■■■■■Federal Democratic Republic of Ethiopia - Ministry of Waler Resources Desk study on Genji CH’.etslon Ail C JI FflasitHfity Study of Haro 1 and 2 Hydropower Projects_________________________  Page 5-7
5.3
From a socio-economic perspective, therefore. AIL C II Option 1 is not preferred in lhe medium to long-term. Socio-economic impacts associated with Alternative A are minimal and will not significantly af fect decision making in this case.
Conclusions - Environmental Study
These conclusions are from a brief remote sensing study only. The Ait. C II Oplion 1 and Baro 1 (worst case scenario) sites were examined. Genji was assessed at the 1350m level and Baro 1 at lhe 1520m level.
The two sites are similar in area with Baro 1 slightly larger 4.000ha as apposed to 3,8OOha. In general lhe soils at Genji appear to be slightly better for agriculture than at Baro 1 as lhe forest contains a greater proportion of the type 'Forest on deep soils* than al Baro 1. There is also more agriculture at Genji (83 ha or lands and coffee as opposed to none m the Baro 1 reservoir).
Clearing of either site will result in large areas of forest being removed (approximately 4,000 ha at Baro and 3,740 ha at Genji), Disturbance to communities will certainly be higher it the Genji site is developed due to length ot the reservoir affecting movement between settlements (31 km as apposed to 17 km) and loss of agricultural lands and poten tial future agriculture
October 2OD4I I I I I
I L
( [I [i
■
■ii
I;
■ .‘.I.-

Summery

Summary: Baro Hydropower Projects Feasibility Study

Feasibility Study of Baro 1 and 2 Hydropower Projects

Desk Study on Genji Diversion Alternative C II

Document Overview

This report presents a desk study comparing the Genji Diversion Alternative C II with the original Baro 1-2 hydropower scheme in Ethiopia. The study evaluates geological, hydrological, environmental, and cost factors.

Key Recommendations

The Feasibility Study should focus on the original Baro 1-2 scheme including Genji Diversion Alternative A
Genji Diversion Alt. C II is not recommended for further study at this time
Increasing the Baro 1 reservoir volume may be preferable to Genji diversion options

Comparison of Options

Option	Key Features	Energy Production	Environmental Impact
Baro 1-2 (Original)	Two dams on Baro River	3100 GWh average annual	4050 ha forest inundation
Genji C II Option 1	120m RCC dam on Genji River	Marginally higher than Baro 1-2	Slightly higher impact than Baro 1-2
Genji C II Option 2	Maintains both Genji and Baro 1 reservoirs	Significant dry season energy increase	Very unfavorable (1130 million m³ reservoir)
Genji C II Option 3	Genji dam raised 10m	Less favorable than Option 2	40 km² inundation
Increased Baro 1 Reservoir	Baro 1 dam raised 15m	Similar to Genji Option 2	36 km² inundation

Key Findings

Cost Analysis

Specific construction costs are similar across all options (~0.19 USD/kWh)
Genji options generally have higher construction costs than Baro 1-2
RCC dam costs decrease with increasing volume (62-95 USD/m³)

Geological Conditions

Genji tunnels may require more rock support than Baro tunnels
Some areas may need lining for leakage prevention

Hydrological Conditions

Annual rainfall ranges from 1700mm at dam sites to 2300mm in higher elevations
Runoff in upper Baro region slightly higher than Sor river (key comparison site)
Flood analysis shows peak discharges up to 2250 m³/s for PMF at Baro sites

Environmental Assessment

Baro 1 (1520m level) would flood ~4050 ha of mostly forest land
Genji (1350m level) would flood ~3840 ha with more agricultural impact
Genji reservoir would be longer (31km vs 17km) affecting more communities

Conclusion

The study concludes that Genji Diversion Alternative C II does not offer sufficient advantages over the original Baro 1-2 scheme to justify further investigation. While some options could increase energy production, they would do so at higher environmental costs. The recommendation is to focus on the Baro 1-2 scheme with possible consideration of increasing the Baro 1 reservoir volume.