Identification of a multipurpose water resources development project in the Yala River basin in Kenya

The objective of this consultancy, Identification of Multipurpose Water Resources Development project in the Yala River Basin, was to identify a Multipurpose Water Resources Management and Development project to:

• Improve water, food and energy security,
• Reduce flow variability,
• Contribute towards improved livelihoods.

Multipurpose storage investments such as hydropower development, expanded irrigated agriculture, watershed management and flood control within the Yala River area could bring major benefits to the inhabitants of the basin and the country’s economy.

Appropriate management interventions can lead to a reduction of the vulnerability of the affected communities to extremes in rainfall variability. Management as well as regulation of water resources is a critical factor underlying efforts to promote growth and raise incomes. The project identified supplemented ongoing initiatives through identification of measures (energy, irrigation, water supply, Tourism, navigation as well as catchment protection), to contribute towards poverty alleviation in the basin, improved livelihood as well as conservation of the watersheds.

The Yala River is estimated to have a length of 219 km and a catchment area draining into Lake Victoria of 3,351 km². It is one of the main Kenyan rivers draining into the lake with a mean annual run off of approximately 1,100 Mm3, which corresponds to around 5% of the total inflow to Lake Victoria. The river takes its source in the Nandi Escarpment water tower and traverses Kakamega, Bondo and Siaya districts.

The main land uses adjacent to the river in this area are livestock grazing, tea and coffee plantations and human settlements. While the width of the main river channel is only about 30m, flood waters spill over a wide flood plain, a considerable part of which is the famous Yala Swamp with few human settlements. Areas of this swamp are being reclaimed for rice growing and for fish farming. In the Yala River Basin there are clear areas of existing and potential economic activity which could benefit from the project. These include :

• Irrigation and drainage projects especially in the Middle and Lower parts of the basin,
• Hydropower – some sites exist for multi-purpose dams at which hydropower could be generated,
• The wide expanses of wetlands for the supply of associated goods and services,
• Ground and surface water for domestic and other water supply,
• Tourism through water sports and eco-tourism opportunities,
• Potential for the use of flood water and increasing carbon sequestration.

With respect to the environment, there are a number of areas which were adequately addressed as part of any multi-purpose project to ensure sustainability. These included:

• Managing the conversion of wetlands for crop production, both for irrigation and dry-land farming is an important issue.
• Ecosystems: The system’s wetlands provide important ecosystem services and slow the flow of runoff thereby controlling erosion and also improve water quality. This is important for fisheries both within the river and the area of outfall into Lake Victoria.
• Watershed conservation and management: watershed rehabilitation and management activities are vital to preserve both livelihoods in these areas and to reduce erosion and sedimentation of the river and its wetlands through soil conservation.