Pengembangan sumberdaya air di das Bogowonto Cokroyasan

ABSTRACT The Bogowonto-Cokroyasan area lies in the east part of South Kedu region. This area has been developed as irrigation area. In the wet season, practically all of the water requirements can be met. However in the dry season, the area suffers water shortages. It is estimated that only 40% of the area could be furnished a full water supply system during the dry season. An identification study, performed by Serayu-Bogowonto River Development Project, recommended the development of the water resources in the Bogowonto-Cokroyasan river basin and identified viable dam sites. The Watupayung damsite was identified on Jali river (tributary of Cokroyasan river), Gegerjeruk on Bogowonto river and Mudalrejo on Jebol river (tributary of Bogowonto river). The three alternative dams are examined to find the most attractive one. The examination is based on water balance analysis in the study area. The water balance analysis consist of the calculation of the water availability and of the water demand, considering reservoir storage proposed in the three alternative water resources developments. The analysis show that Watupayung dam on Jali river can meet a greater proportion of water demand in the area. In the plan for Watupayung reservoir, a weir located downstream of the dam is needed to divert water to Bogowonto river through a main canal of about 4 km long Using weirs existing on the Bogowonto river, water can be supplied to the irrigation area in the Bogowonto river basin