Module M5 : Pre-feasibility Studies of Hydropower Projects ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ ENTRO EASTERN NILE POWER TRADE PROGRAM EDF – Generation and Engineering Division STUDY 73 373 Le Bourget du Lac Cedex France Tel: +33-4-79 60 60 60 Fax: +33-4-79 60 62 35 eMail: [email protected] AfDB http://www.edf.fr PRE-FEASIBILITY STUDY OF DAL HYDROPOWER PROJECT, SUDAN Scott Wilson Kanthack House, Station Road, Ashford, Kent TN 23 1 PP England Tel: +44 (0) 1233 658200 Fax: +44 (0) 1233 658299 eMail: [email protected] http://www.scottwilson.com FINAL REPORT with participation of : - EPS (Egypt) November 2007 - Tropics (Ethiopia) - YAM (Sudan) Eastern Nile Power Trade Program Study Funded by Africa development Bank – Client : ENTRO (Eastern Nile Technical Regional Office Front Page.doc Module M5 : Pre-feasibility Studies of Hydropower Projects Pre-feasibility Study of the Dal Hydropower Project CONTENTS Page 1. INTRODUCTION........................................................................................................... 1-1 1.1 BACKGROUND OF THE NILE BASIN INITIATIVE ...................................................... 1-1 1.2 ORIGIN OF THE STUDY................................................................................................ 1-1 1.3 THE CONSULTANTS..................................................................................................... 1-2 1.4 SCOPE OF THE SERVICES .......................................................................................... 1-2 1.5 PRE-FEASIBILITY STUDIES OF HYDROPOWER PROJECTS .................................. 1-3 2. BACKGROUND TO THE DAL PROJECT ................................................................... 2-1 2.1 PROJECT AREA............................................................................................................ 2-1 2.2 PREVIOUS STUDIES..................................................................................................... 2-1 2.2.1 The Nile Basin ....................................................................................... 2-1 2.2.2 Nile Waters Study (1979)....................................................................... 2-2 2.2.3 Sudan Long-Term Generation Planning Study (Acres, 1993) ............... 2-3 2.2.4 Long Term Power System Planning Study (PB Power, 2006)............... 2-4 2.3 INITIAL REVIEW OF PROJECT .................................................................................... 2-5 2.4 DAL RESERVOIR CHARACTERISTICS....................................................................... 2-6 2.5 REFERENCES................................................................................................................ 2-7 3. HYDROLOGY ............................................................................................................... 3-1 3.1 INTRODUCTION............................................................................................................. 3-1 3.2 CLIMATE ........................................................................................................................ 3-2 3.2.1 Rainfall................................................................................................... 3-2 3.2.2 Temperature .......................................................................................... 3-3 3.3 SURFACE WATER RESOURCES................................................................................. 3-4 3.4 HYDROLOGICAL DATABASE...................................................................................... 3-4 3.5 KEY HYDROMETRIC STATIONS.................................................................................. 3-5 3.5.1 Blue Nile at El Diem............................................................................... 3-5 3.5.2 Blue Nile at Khartoum............................................................................ 3-5 3.5.3 Main Nile at Tamaniat............................................................................ 3-5 3.5.4 Main Nile at Dongola ............................................................................. 3-5 3.6 TIME SERIES FOR FLOWS AT DONGOLA AND DAL SITE....................................... 3-6 3.6.1 Dal Site .................................................................................................. 3-6 3.7 FLOOD STUDY .............................................................................................................. 3-6 3.8 SEDIMENT...................................................................................................................... 3-7 3.8.1 General.................................................................................................. 3-7 3.8.2 Sediment Measurements....................................................................... 3-7 3.8.3 Sediment Deposition in High Aswan Dam Reservoir........................... 3-12 3.8.4 Impact of Merowe Project.................................................................... 3-14 3.8.5 Sediment Balance and Inflow to Dal Reservoir ................................... 3-15 3.9 EVAPORATION............................................................................................................ 3-18 3.10 REFERENCES.............................................................................................................. 3-19 4. RESERVOIR MODELLING .......................................................................................... 4-1 4.1 INTRODUCTION............................................................................................................. 4-1 4.2 DESCRIPTION OF THE RAPSO PROGRAM ............................................................... 4-3 4.2.1 Data input .............................................................................................. 4-7 4.2.2 Results Output....................................................................................... 4-8 Eastern Nile Power Trade Program Study Page (i) Funded by Africa Development Bank - Client: ENTRO (Eastern Nile Technical Regional Office) November 2007 J:\Country\Ethiopia\D107897 ENTRO Eastern Nile Power Trade\Pre-feasibility REPORTS\FINAL REPORTS NOVEMBER\DAL\R17814 Prefeasibility Report FINAL\Contents.doc Module M5 : Pre-feasibility Studies of Hydropower Projects Pre-feasibility Study of the Dal Hydropower Project Contents Page 4.3 APPLICATION OF RAPSO MODEL TO NILE RIVER SYSTEM .................................. 4-9 4.3.1 Blue Nile .............................................................................................. 4-10 4.3.2 Main Nile.............................................................................................. 4-10 4.3.3 Atbara River......................................................................................... 4-11 4.3.4 Reservoir characteristics ..................................................................... 4-11 4.3.5 Reservoir storage ................................................................................ 4-11 4.3.6 Operating rules .................................................................................... 4-12 4.3.7 Irrigation Demand ................................................................................ 4-14 4.3.8 Existing and future irrigation schemes on the Blue Nile and Main Nile 4-14 4.3.9 Irrigation demand modelling ................................................................ 4-15 4.3.10 Total irrigation water requirements ...................................................... 4-16 4.3.11 Evaporation and Losses ...................................................................... 4-18 4.4 DATA FOR RAPSO MODELLING OF DAL................................................................. 4-18 4.4.1 Period of hydrological record............................................................... 4-18 4.4.2 Water inflows ....................................................................................... 4-19 4.4.3 Reservoir levels ................................................................................... 4-19 4.4.4 Electricity supply reliability................................................................... 4-19 4.4.5 Reservoir characteristics and minimum operating levels..................... 4-19 4.4.6 Evaporation losses .............................................................................. 4-19 4.4.7 Spillway characteristics........................................................................ 4-20 4.4.8 Generating sets installed and allowances for plant maintenance........ 4-20 4.4.9 Penstocks and friction losses .............................................................. 4-20 4.4.10 Turbine and generator characteristics ................................................. 4-20 4.4.11 Electricity demands.............................................................................. 4-20 4.4.12 Generation monthly rule levels ............................................................ 4-20 4.4.13 Numbers of generating sets operated ................................................. 4-21 4.4.14 Environmental releases ....................................................................... 4-21 4.4.15 Tailwater characteristic........................................................................ 4-21 4.5 RESULTS ..................................................................................................................... 4-21 4.5.1 Kajbar and Low Dal without any new Ethiopian scheme..................... 4-21 4.5.2 Kajbar and Low Dal with Mandaya .....................................................