Lake Ziway

Results Central Rift Valley

An important task of the project is to demystify prejudices and to reveal misconceptions with respect to past and on-going developments in the Central Rift Valley.

Some conclusions based on our research:

  • In contrast with the common believe, the soda ash factory along Lake Abyata nor the greenhouses along Lake Ziway are the major water consumers in the Central Rift Valley. The open-field irrigated horticulture sector is by far the largest consumer of fresh water resources in the Central Rift Valley.   
  • Recent reductions in the level of Lake Ziway and Lake Abyata are associated with land developments (especially the expansion of irrigated agriculture) in the catchment of Lake Ziway and along the Bulbula River.
  • Further uncoordinated exploitation of the land and water resources may have dramatic consequences for the local population and development options as Lake Ziway may become a closed lake resulting in increased salinity levels of the largest fresh water reservoir in the region.
  • The dam that is currently being constructed in the Bulbula River is expected to further reduce the outflow by the Bulbula River to discharge levels that are well below the critical environmental flow required to keep Lake Ziway fresh. Obviously, the water availability for people and ecosystems downstream of the dam will be negatively affected in that case.
  • There is no evidence that the amount of rainfall in the Central Rift Valley has decreased in the past 30 years. Hence, the rapid shrinkage of Lake Abyata in the last 10 years can not be related to lower rainfall.
  • Although the open-field horticulture sector provides income to a growing part of the population in the Central Rift Valley, the little information available suggests that its economic performance is generally poor and associated with low water use efficiencies.

Further support of these conclusions can be found in the various publications available on this website.

Some of these conclusions are difficult to accept by policy makers and other stakeholders as they conflict with government policies, with activities of various development organizations and with common believes and opinions. Through publications, presentations, and organization of stakeholder workshops the project stimulates the policy dialogue required for improving natural resources planning, management and decision making in the Central Rift Valley. Coherent policy development and integrated use and management of water, land and related resources is imperative to ensure the sustainable development of the Central Rift Valley, i.e. without compromising the resource base and potential livelihoods of the local population.