Design Criteria Of Rainfall And Runoff Harvesting: Case Study In Upper Cisadane Watershed

Flood and drought are natural phenomenon that can decrease an agriculture production, leading to threaten national food security. Quantitatively a flood is caused by the presence of a gap between distribution and storage of water. Uneven rainfall distribution by spatially and temporally has caused oversupply of water in the rainy season and water shortage in the dry season. The technology of soil and water conservation consists of several methods by through rainfall and run off harvesting using farm reservoir (embung), channel reservoir etc. The research was conducted at Cisadane upper watershed in March until November 2011. The aims of the research were: to characterize biophysics conditions of research area to assess the suitability of rainfall and runoff harvesting technique, and to develop a model for water management using the technique of rainfall and runoff harvesting in order to anticipate flood and drought, and to develop design criteria of a technique of rainfall and runoff harvesting for alleviating the risk of flood and drought. Result of the research showed that there are 41 channel reservoirs could be constructed at Cikereteg sub watershed, Cisadane upper watershed to irrigate 50.4 ha target areas. While at Cisadane upper watershed 159 channel reservoir, could be constructed to diminish 4.5 m(3)/sec of peak discharge.