Read the full profile
Environment and health
The main environmental issues related to water management are erosion and siltation of water infrastructures. Water pollution is still mostly limited to urban and industrial areas, but soil salinization is directly linked to irrigated agriculture.
Erosion and sedimentation
Erosion is caused by natural factors, such as topography, torrential rains and wind. It is also caused by human activities, in particular deforestation for agriculture, charcoal, construction, mining, or by grazing, all due to unsustainable utilization and rapidly expanding human and livestock populations. Annual soil erosion amounts to about 1 900 million tons/year, impacting water, land and agricultural productivity (IWMI, 2010). Since the majority of the main rivers have their headwaters in the highlands parts of the country, their silt content is high. As a result, water bodies are silting up, especially in the Abbay basin (ODI, 2015). Sedimentation in dams, such as the Koka, Aba Samuel, Borkena and Gondar, reduced their storage capacity. Water levels of natural lakes have decreased, in particular Awasa, Abaya, Alemaya, Lange, Rudolf, Chew Bahir, Adele and Zway, and some show signs of drying up. Finally, a number of rivers change their courses due to siltation, particularly during the rainy season, resulting in yearly flooding in the areas near the riverbanks. This is particularly the case of the Lower Awash river (EPA, 2003 and EPA and UNEP, 2008).
Water pollution is still limited to industrial, mining and urban areas (EPA, 2012), but is a growing problem in the Awash river basin, due to major cities and industries in the Upper basin. In early 2000s, about 80 percent of industries around Addis Ababa discharged their waste into nearby water bodies without any treatment. Tributaries of the Awash river around Addis Ababa and Nazareth are polluted (EPA, 2003). Pollution causes water hyacinth infestation in Lake Koka, algal bloom in Lake Aba Samuel, industrial pollution of the Akaki river and nitrate pollution of the Awash river (ODI, 2015).
Salinity problems due to waterlogging were observed in irrigated lands along the Awash river. In the 1980s, thousands of hectares of the Amibara plantation for cotton, in the middle Awash basin, had to be abandoned after less than five years of irrigation farming due to faulty drains (WB, 2007).