Ruiru Dam Bathymetric Survey

Launching of Bathymetric survey equipment at Ruiru dam. From left: Prof. Mati (Director WARREC), Eng. Muguna (Technical Director, NCWSC), Prof. Kahangi (DVC RPE) and Eng. Gichuki (MD, NCWSC)

Reservoir sedimentation is a recurrent problem in Kenya, caused by escalating soil erosion, particularly from the highland areas, which have the combination of steep slopes, erodible soils and high rainfall. Until now, there was no way of determining reservoirs sedimentation, or the types and sources of these sediments in Kenya. This was until the introduction of the first State-of-the-Art Multi-Frequency Reservoir Survey Equipment (bathymetric boat) in Kenya, through a project pioneered by JKUAT in collaboration with the Nairobi City Water and Sewerage Company (NCWSC).

The initiative to bring a bathymetric boat to Kenya was pioneered by JKUAT lecturer, Dr. Joseph Sang, who in 2012, organized for the donation of the Bathymetric Boat, by United States Agency for International Development (USAID), through the United State Department of Agriculture–Agricultural Research Services (USDA-ARS) and Baylor University (Waco TX) to JKUAT. The Nairobi City Water and Sewerage Company (NCWSC) was the first to use the equipment with the sediment assessment conducted at Ruiru Dam, launched in a ceremony officiated by JKUAT’s DVC-RPE, Prof. Esther Kahangi, on 13th July 2015. 

Ruiru dam. Dr. Sang (standing) demonstrates how the Bathymetric survey equipment works. On board are Prof. Kahangi and Eng. Gichuki and Eng. Muguna.

Since then, the bathymetric equipment has been used to assess the sediment yields in Ndakaini Reservoir and Lake Naivasha with results being used in watershed modelling studies. The equipment has been used to supports PhD, MSc and BSc students’ research projects. The bathymetric equipment can be hired for use by other institutions or researchers.