Environmental and Social Impact Assessment - Gibe III

Gibe III – Environmental and Social Impact Assessment 300 ENV R CS 002 C – A9003099
List of Figures
Figure 0.1: Location Map of the Project Area .............................................................................................. 2
Figure 0.2: Administration Map around the Reservoir Area ........................................................................ 3
Figure 0.3: General Layout of the Site Installations ..................................................................................... 5
Figure 0.4: Chida - Sodo Road Realignment Change................................................................................... 6
Figure 2.1: The SNNPR Region, Zones and Weredas................................................................................ 35
Figure 3.1: Gibe III project area ................................................................................................................. 45
Figure 3.2: Gibe cascade location............................................................................................................... 46
Figure 3.3: Access road to the dam site ...................................................................................................... 51
Figure 3.4: Tunnels rating curve................................................................................................................. 52
Figure 3.5: Spillway rating curve (gates fully open) .................................................................................. 56
Figure 3.6: Water profile and velocity on the chute with the PMF............................................................. 57
Figure 3.7: General Quarries Location .......................................................................................................66
Figure 3.8: Detail of the river alluvium and basalt quarries ....................................................................... 67
Figure 5.1: Annual Isohyetal map reported in the Omo River Master Plan ............................................... 75
Figure 5.2: River system of the catchment area.......................................................................................... 95
Figure 5.3: Gibe III basin DTM.................................................................................................................. 96
Figure 5.4: Annual Isohyetal map reported in the Omo River Master Plan ............................................... 98
Figure 5.5: Monthly rainfall at Wolkite station (1985-2004) ................................................................... 101
Figure 5.6: Monthly rainfall at Bonga station (1953-2003)...................................................................... 101
Figure 5.7: Annual runoff for the Shebe station on the Gojeb River........................................................ 104
Figure 5.8: Gibe III Basin – Regional Areal Rainfall Curves................................................................... 112
Figure 5.9: Gibe III Basin - HEC HMS Hydrologic model ...................................................................... 113
Figure 5.10: Gibe III Dam Site – Extreme Flood Hydrographs.................................................................. 118
Figure 5.11: Land Cover of the Gibe III Reservoir Area............................................................................ 123
Figure 5.12: Administration Map around the Reservoir Area .................................................................... 138
Figure 5.13: Ethnic Groups Map in the Omo Valley.................................................................................. 141
Figure 5.14: Land Cover along the Lower Omo River............................................................................... 160
Figure 5.15: Average monthly runoffs at Gibe III, Residual and Lake Turkana. ....................................... 163
Figure 5.16: Location of Recessions Agriculture Sites along the Lower Omo River................................. 169
Figure 5.17: Locations of Existing and Potential Irrigation Sites along the Lower Omo River................. 173
Figure 5.18: Locations of Fishing Sites along the Lower Omo River ........................................................ 179
Figure 5.19: Locations of National Parks and Other Protected Sites along the Omo River ....................... 181
Figure 7.1: Locations of the Proposed Buffer Area .................................................................................. 208
Figure 7.2: Locations of Affected Road Section and River Crossing Sites along the Omo River ........... 224
Figure 7.3: Comparison of Monthly flows with and without Gibe III...................................................... 227
Figure 7.4: Monthly flows at Lake Turkana: average 1964-2001 ............................................................ 228
Figure 7.5: Monthly flows at Lake Turkana: dry year 1987 (min flows) ................................................. 228
Figure 7.6: Overall layout of the Gibe Hydroelectric scheme .................................................................. 238
Figure 7.7: General Layout of the Gibe Cascade...................................................................................... 239
Figure 12.1: Schedule for Implementation of Environmental and Social Mitigation, Management and
Monitoring Plan ...................................................................................................................... 279
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