Lake Victoria South Basin Area (LVSBA)
Lake Victoria South Catchment (LVSBA) is in the southern part of Lake Victoria basin in Kenya. The Basin Area is about 31,734 km2 out of which 4, 128 km2 is lake waters constituting about 13% of the Basin Area.
Topography and Land Cover
The topography of the Basin Area consists of low rolling hills separated by wide flat valleys that have been developed for intensive agriculture. The area has a gently sloping landscape and eroded surface in some places that expose rock outcrops like the Nyakach and Manga plateaus.
Water Resources in the Catchment
The catchment comprises six major drainage systems of
- Nyando, Sondu, Gucha-Migori, Northern and Southern Shoreline Streams
- Mara which is a trans boundary resource shared between Kenya and Tanzania.
The catchment covers Kisumu, Homa-Bay, Kisii, Nyamira, Migori, Kericho, and Bomet Counties and parts of Siaya, Vihiga, Nandi, Nakuru, Narok, Uasin-Gishu, and Baringo Counties.
In LVSBA, the Gucha-Migori River, with a mean monthly discharge of 1.83m3 /s has the highest contribution of water to Lake Victoria, whereas Mara River has the largest drainage area.
Drainage systems and counties in LVSBA
The Lake Victoria South Basin Area and its surrounding scarps and uplands are a moist belt. Except for the areas adjacent to the lake, rainfall occurs from March to November. The Kisii, Kericho, Bomet and Trans Mara highlands receive more than 2400mm of rainfall in March to May and from July to September. The Basin Area has a mean annual rainfall of 1,280 mm.
The annual water demands were summarised as follows;
Water Demands (MCM/year)
-Source: National Water Master Plain, 2030
In LVSBA, the major land use types are forests, rangelands, croplands, rivers/water bodies and their riparian zones, urban and built-up areas, rural settlements, national park/reserve, springs and groundwater recharge areas and wetlands.
- Forest Areas: include Eastern and south-western Mau forest reserve (in Nakuru and Bomet Counties), Kisii and Nyamira forests (in Kisii and Nyamira Counties), South Nandi forest (in Nandi County), Londiani forest reserve (in Kericho and Nakuru Counties), Chepalungu Forest (in Bomet County), Transmara Forest (In Narok County), Tinderet, Timboroa, and Mt. Londiani forests (in Nandi, Kericho, UasinGishu, and Baringo Counties).
- Croplands and Rangelands: Croplands and rangelands constitute the largest land use areas in the catchment. The farming practices in the cropland areas have the potential to reduce on-farm soil erosion, sources of fertilizer pollution, and improved livelihoods.
Classification of Catchment Management Units
Following the delineation of the Basin Area into CMUs, a Water Resources Classification System (WRCS) was introduced to capture the level of importance attributed to the resource in the management units with respect to three broad types of demands, namely; ecological, livelihood and commercial.
The classification system is mandated under Section 12 of the Water Act 2002 and is a measure of the relative importance attributed to the three competing types of uses: – Ecological (Environmental), Livelihood and Commercial. The class of the resource imposes certain conditions on the utilization of the resource with respect to the Reserve and the Resource Quality Objectives. The water resources classification is a set of guidelines and procedures that, when applied to a specific management unit, will ultimately assist in the process of maintaining a balance between protecting the water resources and using them to meet economic and social goals.
LVSBA Management Sub-regions and Management Focus
List of Endagered rivers in LVSBA
Major Water Resources Management Challenges
- Catchment Degradation: The wetlands and riparian zones have suffered degradation through human encroachment for settlement, expansion of crop production, urbanization, livestock grazing, and commercial activities such as brick-making
- Unsustainable farming practices such as agro-pastoralism which leads to the consequent loss of the protective vegetation cover. Their fragile soil once disturbed by cultivation becomes easily eroded during rainy season.
- Pollution especially in the mid and lower zones of Nyando River basin as a result of discharge of industrial effluents and non-point sources especially agrochemicals emanating from sugarcane, maize and tea plantations
- Flooding which occurs in areas such as Kano Plains, parts of Nyakach within Nyando river basin, parts of Awach tende river basin, and Lower Gucha-Migori river basin
- Encroachment to riparian land and wetlands
WRA’s efforts in Curbing Water Conservation Concerns in Lake Victoria North Basin Area
Trans Nzoia County has two major water towers namely; Mt. Elgon and Cherengany Hills and two major rivers namely Nzoia and Suam. Kitale Sub Region manages the Nzoia basin which has the following major tributaries: Koitobos, Ewaso Rongai, Noigameget, Sinyereri, Suwerwa, Losorwa, Chepkaitit, Khybe, Kisawai, Kiptogot and Kaibei.
Water Basin Areas in Kitale face a number of issues ranging from water pollution through solid waste and sedimentation of rivers from soil erosion emanating from poor land use practices.
WRA is undertaking strong sensitization campaigns and capacity building of WRUAs in collaboration with stakeholders regarding waste disposal and proper land use practices.