Challenges for water quality protection in the greater metropolitan area of Addis Ababa and the upper Awash basin, Ethiopia – time to take stock

Abstract

Ethiopia, the second-most populous country in Africa after Nigeria, has more than one hundred million people and is one of the world’s fastest-growing countries in terms of economy. It has 12 major river basins with an annual renewable flow of 122 billion m3. The country is facing increasing pressures on water resources both in terms of quantity and quality. Many researchers have highlighted that water pollution is severe and increasing particularly in the environs of Addis Ababa because of complex anthropogenic factors. The objective of this review was to synthesize the key results of research to date on the water quality in the environs of Addis Ababa and use that information to highlight management gaps, challenges, and future research needs. According to the studies reviewed, water pollution pressures result from rapid urbanization and industrial expansion without adequate solid waste management and wastewater treatment facilities, and agricultural activities. The problems are compounded by law enforcement difficulties. Trace metal contamination of rivers, streams, reservoirs, and their bioaccumulation in vegetables highlight the urgency of addressing water pollution in the upper Awash catchment. Most studies agreed that water from reservoirs, rivers, and streams in the environs of Addis Ababa is unfit for human consumption as it contains a wide range of pollutants that could affect community health. Hence effective pollution detection, mitigation measures, and monitoring including the development of bioassessment tools, together with cost-effective management measures are urgently required to reverse the decline in water quality in Ethiopia in general and in the greater metropolitan area of Addis Ababa and the upper Awash basin in particular.