GROUNG WATER RESOURCES
Ethiopia has abundant surface and ground water resources potential of which groundwater has a lion-share. The preliminary estimated amount of yearly groundwater recharge of the country is about 28,000 Mm 3 . Recent studies indicated that the potential is much greater than this amount. Most of the developed groundwater resources is mainly used for domestic and industrial water supply. So far, only 20.4% of the Ethiopian landmass has been mapped at 1:250,000, 36.8% at one million scale and the whole country at two million scale (Ethiopian Geological Survey).
Ground waters in unconsolidated aquifers are usually of excellent quality; being naturally filtered. The water is normally clear, colorless, and free from microbial contamination and thus requires minimal treatment. As a consequence of the slow travel times in the flat plains and due to the long contact time with the sediment, the groundwater often contains significant quantities of minerals in solution. This solute content varies and depends on the residence time of water in the aquifer and the mineral composition of the aquifer itself as seen in the flood plains of the alluvial aquifers in the Rift Valley.
High concentrations of fluoride are also common in most of the Rift Valley boreholes and springs. The concentrations are above 1.5 parts per million (ppm) which is over the limits for drinking water established by the World Health Organization.
In the urban centers, industrial effluents and leaky septic tanks are becoming a threat as contaminants of ground water, which has repeatedly been manifested from hydro geological investigations carried out in several major towns like Dire-Dawa, Jimma, Dessie etc and substantiated by the high concentrations of nitrates in these localities.
ENGDA (Ethiopian National Groundwater Database)
Groundwater database is playing an important role in understanding the hydrologic cycle and discharge –recharge relation, for assessing and managing water resources with in the hydrogeologic environment.
ENGDA is implemented jointly by the Ministry of Water Resources, Addis Ababa University , and the Geological Survey of Ethiopia in close collaboration with the Regional Water Resources Development Bureaus, Water Work Enterprises and NGOs. The success of the establishment of ENGDA is due to the on-going studies and sustaining the capabilities built through our technical cooperation with the IAEA in the past several years. The success of our technical cooperation projects depends on our capability to collect, process, interpret and archive the relevant hydrogeological and hydrological data. ENGDA is a necessary tool that is critical to the successful implementation of the proposed Ethiopian Groundwater Resources Assessment Program (EGRAP) that has been submitted to the Government for approval. This project is aimed at mapping and investigating the groundwater resources of the entire nation within a period of 12-15 years.
The development of the Ethiopian National Groundwater Database (ENGDA) was started in 2003 by USGS experts in collaboration with the Ministry of Water Resources (Hydrology Department) under the project ETH/8/007 which is supported by the International Atomic Energy Agency (IAEA) and finalized in January 2005.
ENGDA is implemented in Microsoft Access and is designed to input, store, analyze and report ground-water information. Ground-water data stored in ENGDA includes site information, borehole details, water-level and water quality.
The Ministry of Water Resources, Hydrology Department has a plan to train all regional water bureaus' ground-water related professionals about ENGDA database and the associated standardized field forms usage so that all ground-water data of the country be stored and managed systematically.
Groundwater Potential (Aquifer Productivity) Maps
Groundwater Quality Map
Boreholes and springs by Basin
Boreholes and springs by Region