Tana Sub-Basin Land Use Planning and Environmental Study Project
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Tana Sub-Basin Land Use Planning and Environmental Study Project BoEPLAU Hydrology and Water Resource Assessment Report, ADSWE Page I Tana Sub-Basin Land Use Planning and Environmental Study Project Amhara National Regional State Bureau of Environmental Protection, Land Administration and Use (BoEPLAU) Tana Sub-basin Land Use Planning and Environmental Study Project Technical Report III: Hydrology and Water Resource Assessment (ADSWE, LUPESP/TaSB: sII, vIII/2014) January, 2014 Bahir Dar Client: Bureau of Environmental Protection, Land Administration and Use (BoEPLAU) Address: P.O.Box: 145 Telephone: +251-582-265458 Fax: (058) 2265479 E-mail: Amhara [email protected] Consultant: Amhara Design & Supervision Works Enterprise (ADSWE) Address: P.O.Box: 1921 Telephone: +251-582-181023/ 180638/181201/181254 Fax: (058) 2180550/0560 E-mail: amhara [email protected] BoEPLAU Hydrology and Water Resource Assessment Report, ADSWE Page II Tana Sub-Basin Land Use Planning and Environmental Study Project List of report Section I: MAIN REPORT Section II: SECTOR STUDIES Volume I: Soil Survey Volume II: Forest and Wildlife Assessment Volume III: Hydrology and Water Resource Assessment Volume IV: Land Use and Land Cover Volume V: Agro Climatic Assessment Volume VI: Crop Resource Assessment Volume VII: Watershed Management Volume VIII: Livestock and Feed Resource Assessment Volume IX: Human Health Assessment Volume X Animal Health Assessment Volume XI: Fish and Wetland Assessment Volume XII: Sociologic assessment Volume XIII: Economic Study Volume XIV: Tourism Assessment Section III PLANNING Volume I Approaches, Procedures and Methods Volume II Land Utilization Types Description and their Environmental Requirements Setting Volume III Planning Units Description Volume IV Land Suitability Evaluation Volume V Land Use Plan Volume VI Management plan Volume VII Implementation Guideline SECTION IV ANNEXES Maps albums and data base BoEPLAU Hydrology and Water Resource Assessment Report, ADSWE Page III Tana Sub-Basin Land Use Planning and Environmental Study Project Executive Summary Lake Tana and its basin are valuable for many people, including the communities who live in the basin, around the lakeshore, those living on islands and close to the Blue Nile River. The area has been identified as a region for irrigation and hydropower development, which are vital for food security and economic growth in Ethiopia. This report presents findings from an integrated multidisciplinary study that was conducted to investigate the implications of water resource development. The study comprised three components: i) Water resource development in the sub-basin which include irrigation and water supply development and their problems; ii) Assessment of water demand and use on water supply, irrigation, industrial, hydropower and others; iii) Assessment of drinking water quality and sanitation of the sub-basin; iv) Hydrological water balance of the sub-basin; v) Surface and groundwater potential of Tana Sub-Basin; and vi) Land Utilization Types (LUTs) for irrigation The study found that existing water resources development of Tana Sub-Basin holds the great portion of the resource found in Blue Nile Basin. Existing information indicates that from 1,001,000 ha irrigable land of Blue Nile Basin (WAPCOS, 1995), Tana Sub-Basin holds 188,637.39 ha (Based on ADSWE assessment) which is 19% from the total. Irrigation practices like Modern River and spring diversion, traditional river and spring diversion, pump irrigation and irrigation with fetching are common in the basin. For these irrigation practices 85% of the water sources are rivers. This study also identifies the water supply schemes development. There are totally 105 (93 functional and 12 non- functional) urban water supply schemes and 4818 (3497 functional and 1321 non-functional) rural water supply schemes inventoried. From the functional urban water supply schemes boreholes are 68, hand dug wells 10, shallow well 1, springs 13 and surface water 1. The rural water supply sources include 3738 (77.6%) Hand Dug Wells (HDW), 746 (15.5%) springs, 197(4.1%) pipe supply from the nearest towns and others 137 (2.8%) surface water (river, pond and lake). Wells and springs make 93.1 % of the total number of schemes. This figure indicates that drinking water supply for human use in Tana Sub-Basin is ground water. According to ADSWE rural water supply inventory actual coverage of safe drinking water of the sub-basin is 48.5% by considering developed hand dug wells and springs only. When undeveloped hand dug wells and springs are included in the analysis the coverage become 82.4%. Whereas Safe drinking water coverage with access of the sub-basin by considering developed hand dug wells and springs only is 46.7%. When undeveloped hand dug wells and springs are included BoEPLAU Hydrology and Water Resource Assessment Report, ADSWE Page IV Tana Sub-Basin Land Use Planning and Environmental Study Project in the analysis the coverage become 80.6%. The existing water resource development problems were also identified during the study. These are lack of land and water management practices, disturbance of river morphology and change of river mouth and Lake Boundary due to siltation and sedimentation. Related to water demand and use of the sub-basin, the study identifies the main water user sectors and their annual water demand. The first and the large user of water of the Sub-basin is hydropower. In 2012/2013 the water used for Tana Beles hydropower generation was 2.58 BCM. The second water consumer is irrigation. For the existing practices of modern and traditional irrigation 1,760.904 MCM (1.8 BCM) of water is required. Futures, under construction and under medium and large scale irrigation practices are highly demanding sectors. 1,442 MCM, 72569 MCM and 61.56 MCM of water required for planned, under construction and under irrigation practices respectively. Under urban water demand 9.601, 2.125 and 0.582 MCM of water required for public, both public & commercial and industrial consumption respectively. Under rural water demand 12.867 and 26.5 MCM of water required for human and livestock respectively. Navigation, tourism, fisheries and floriculture are other users of water. Drinking water quality and sanitation is the other part which this study addresses. One micro- biological, two chemical and seven aesthetic parameters were assessed on 131 samples of urban and rural water supplies of the sub-basin. These parameters are total coliform from micro-biological; nitrate and floured from chemical; iron, manganese, turbidity, Total Dissolved Solids (TDS), salinity and pH from aesthetic parameters. For all the parameters all the samples are complied 98-100% with the national and WHO Guide line except turbidity, nitrate and total coliform which are 69.5%, 84 % and 31.3% complied respectively. This may be due to sanitation problems and turbid nature of rural water supply schemes especially hand dug wells. Careful management of water in all aspects of practices like irrigation, water supply and other sectors play a significant role for beneficiaries for a sustainable use. To keep the basin water potential, the future land and water management practices should be implemented throughout the sub-basin. BoEPLAU Hydrology and Water Resource Assessment Report, ADSWE Page V Tana Sub-Basin Land Use Planning and Environmental Study Project Table of Contents LIST OF REPORT --------------------------------------------------------------------------------------------- III EXECUTIVE SUMMARY ------------------------------------------------------------------------------------ IV LIST OF FIGURES ----------------------------------------------------------------------------------------------IX LIST OF TABLES --------------------------------------------------------------------------------------------- XII ABBREVIATIONS AND ACRONYMS -------------------------------------------------------------------- XV 1. INTRODUCTION ------------------------------------------------------------------------------------------- 1 1.1. Background ---------------------------------------------------------------------------------------------------------------------------------------- 1 1.2. Water Resource and Irrigation Development ------------------------------------------------------------------------------------------- 2 1.3. Water Demand and Use ----------------------------------------------------------------------------------------------------------------------- 3 1.4. Water Quality and Sanitation ---------------------------------------------------------------------------------------------------------------- 4 1.4.1. Drinking-Water Quality and Health----------------------------------------------------------------------------------------------------- 4 1.4.2. Drinking Water Sources and their Degree of Health Risk ------------------------------------------------------------------------ 5 1.4.3. WHO‘s framework for safe drinking-water ------------------------------------------------------------------------------------------- 6 1.4.4. Rapid Assessments of Drinking-Water Quality -------------------------------------------------------------------------------------- 7 1.5. Basin Water Balance---------------------------------------------------------------------------------------------------------------------------- 8 1.6. General Objectives of the Study ------------------------------------------------------------------------------------------------------------ 9 1.7. Scope of the Study