Lesson learnt from land use management through Integrated Soil and Water Conservation (ISWC)

Abstract

River Nyando is one of seven major rivers within the Kenyan side of the Lake Victoria Drainage Basin. The other six rivers are Sio, Nzoia, Yala, Mara, Sondu-Miriu and Kuja- Migori. The Nyando and Nzoia rivers have been the main sources of seasonal flooding in downstream areas before their waters enter Lake Victoria. The Nyando has its tributaries originating from the Nandi and Tindiret Hills in South and North Nandi Districts and Londiani, Tindiret and West Mau Forests in Kericho and Nakuru Districts. River Nyando has a total length of 170 km and a catchment area of 3450 km2. The Nyando Drainage Basin consists of five main sub-catchment areas namely:- Nyando-Nandi; Nyando-Kericho; Awach-Kano; Nyaidho-Kano; and Nyando-Kano. More than 50% of the total water discharge of the Nyando comes from the Nyando-Nandi sub-catchment area. River Nyando traverses Londiani, Kipkelion and Sigowet areas of Kericho District and Koru, Muhoroni, Chemelil, Lower Nyakach and Kano Plains areas of Nyando District. Londiani, West Mau, Kipkelion, Sigowet and Koru areas form the highlands zone whereas Muhoroni, Chemelil, Lower Nyakach and Kano Plains form the lowlands zone of the drainage basin. The highlands zone is characterized by a very rugged terrain particularly in Kipkelion, Aldai, Kaptumo, and Tinderet Divisions. The mean annual rainfall ranges between 1000 mm (in Tinderet Forest) and 1600 mm (in Kipkelion). The total land areas covered by West Mau Forest, Kipkelion and Londiani are 573 km2 , 441 km2 and 238 km2 respectively. The average annual rainfall for these areas is 1660 mm, 1390 mm and 1250 mm respectively. The dominant soils in the highlands zone include Nitisols, Phaeozems, Luvisols and Cambisols. These soils are well drained, deep and dark reddish brown sandy clay loam to clay. The Phaeozems and Cambisols are dominant in Kipkelion and have a rocky or stony surface. The Nitisols are found in the West Mau Forest area. Most of the soils in the highlands are overlain by humic topsoil