Identification of a multipurpose water resources development project in the Gucha-Migori River basin in Kenya

The objective of this consultancy, is to identify a Multipurpose Water Resources Management and Development project to: i) Improve water, food and energy security; ii) Reduce flow variability; and iii) Contribute towards improved livelihoods.

Multipurpose storage investments such as hydropower development, expanded irrigated agriculture, watershed management and flood control within the Gucha-Migori 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 to be identified needs to supplement 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 Gucha-Migori River is one of the contributors to Lake Victoria. The river basin has three main tributaries namely the Gucha (North), Migori (South) and the Riana Rivers. The Riana River is an influent of the Gucha River. The Gucha River takes its source in the Kissi Highlands while the Migori takes its source in the Transmara Forest at 2 500 amsl. The mean annual discharge of the river entering Lake Victoria is estimated at nearly 1 850 Mm3, approximately 7.5% of the total inflow into Lake Victoria.

The hydrology of the Gucha Migori River is characterized by two distinct periods of high flow corresponding to the two rainy seasons, March-May and September-November. The forests of the source areas have become progressively degraded over the last 50 years as a result of anthropogenic pressures. This catchment degradation has played a major role in altering the flow regime of the river which is now characterized by higher flood peaks and lower ‘base’ flow during the periods between rainy seasons.

Soon after the confluence of the Gucha and Migori Rivers the river enters into a flat and swampy area and form a delta at its entry to the lake. In recent years, the Gucha River has straightened and deepened itself as a result of exceptionally high floods and perhaps a lowered Lake Victoria water level. The result is that the flood plains are much less frequently and severely flooded. Areas of this swamp are being reclaimed agriculture.

In the Gucha-Migori River Basin there are clear areas of existing and potential economic activity which could benefit from the project. These include : i) Irrigation and drainage projects especially in the Middle and Lower parts of the basin; ii) Hydropower – some sites exist for multi-purpose dams at which hydropower could be
Generated; iii) The wide expanses of wetlands for the supply of associated goods and services; iv) Ground and surface water for domestic and other water supply; v) Tourism through water sports and eco-tourism opportunities; vi) Potential for the use of flood water and increasing carbon sequestration.

With respect to the environment, there are a number of areas which would have to be adequately
addressed as part of any multi-purpose project to ensure sustainability. These include: i) Managing the conversion of wetlands for crop production, both for irrigation and dryland farming is an important issue; ii) Ecosystems: The system’s wetlands provide important ecosystem services and slow the flow of runoff thereby controlling erosion and also improve water quality; and iii) 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.