LAKE VICTORIA BASIN

Water Resources

According to the Transboundary Diagnostic Analysis (Lake Victoria Basin Commission, 2007) of the LVB, Kagera River has the largest inflow into the Lake. The Kagera River originates from Rwanda and Burundi, as well as from parts of south-western Uganda. The river contributes up to 33 per cent of Lake Victoria’s riverine inflow. The other rivers in the basin are the Bukora and Katonga which originate from Uganda; the Nzoia, Sio, Mara, Yala, North and South Awach, Gucha- Migori and Sondu which originate from Kenya; and the Mori and Simiyu, which originate from Tanzania. Groundwater plays a significant part in the water balance of the sub-catchments of the LVB, and provides about 40 per cent of the baseflow during the dry season. The importance of groundwater is shown by the large areas of wetlands in the Lake Victoria Basin, which would not exist without baseflow. The decline in Lake Victoria water level of approximately two metres between 1999 and 2006 is closely linked to the drop

in groundwater levels. The partial rebound of Lake levels between 2006 and 2009 was partly due to higher precipitation, which also caused greater groundwater recharge (UNEP 2010). The wetlands of the LVB cover a significant area, with those in Kenya and Uganda constituting approximately 37 per cent and 13 per cent, respectively, of the total surface area of wetlands in the two countries (Lake Victoria Basin Commission 2007). In Kenya, major wetlands include the Yala Swamp, covering an area of 17,500 ha; the Nyando Swamp; the Sondu-Miriu Wetlands at the mouth of the Sondu River; the Saiwa Swamp on the Nzoia River; and the Kimandi River Wetlands on the tributary of the Yala River (Lake Victoria Basin Commission 2007). Tanzania’s wetlands cover 422,000 ha, and are found in 28 sub-basins of the Tanzanian part of the Lake Victoria Basin. Of these, 14 per cent are permanent swamp

Wetlands filter harmful substances, protect against floods and soil erosion, and provide food and habitat

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