Participatory valuation of water uses between irrigation crop system and other users the case study of Pangani River Basin

Population growth in Pangani River Basin (PRB), need for more agricultural lands in which 80% of inhabitants depend on for their livelihood, presence of factories from upstream to downstream and flow control for hydropower production are putting the strainon the management of the available water resources in PRB. Growing pressure on water resources. increaqng interdependencies: between users, associated increases in demand for reliable water services and increasing complexity in water resource management are main challenges in PRB. This study estimates the spatial and temporal variation of surface water resources. amount of and location of water uses upstream and downstream Nyumba ya Mungu (NYM) Dam and hence values of water for different uses and location for major users and selected villages. The study carries out participatory valuation and employs the CROPWAT model, water availability, water demand data. literature and different earlier surveys in PRB Using climate data mainly precipitation differences within the PRB, the basin was divided into three assessment zones. The available water in PRB found to be high upstream, slightly decreases at the middle and slightly increased as moving downstream. Water consumptions for domestic uses decrease as moving downstream. More abstraction for irrigation found middle stream while use by factories is also high middle stream. Water required for power generation decreases from middle to downstream. The value of water in use found to be high for irrigation upstream about 6.5 US$/m3andlowestabout0.0042US$/m 3 for power production middle stream. The factories water use value is also decreasing downstream. Domestic water value is increasing as moving downstream, the value for upstream, middle and downstream zones are 1.07. 1.4 and 1.5 US$/m 3 respectively.