Water balance analysis in perennial river flow: case study Pulau Laut, South Kalimantan

Water scarcity in dry land region is main problem which need to be solved as long the agricultural activity existed. The common technical way to sustain water is capturing rainfall and runoff and stored locally before they go through to the sea. Channel reservoir is simple water infrastructure or dam which consists of reinforced wall constructed by crossed a river channel to store run off flow and facilitate aquifer recharge. This paper aims to calculate a water balance to quantify the amount of water between the dam and hydrological system. Estimation of water balance is generated from rainfall data by Mock, Penman, and linked by mass conservation method. Volume of water during the dry season was gained consistently by 1964.53 m3 where it was above the minimum operation and the live storage capacity of this reservoir about 2,531 m3 where it was adequate to cover water demand for irrigation purpose. In conclusion, channel reservoir can utilize intermittent river channel to store water and be treated as isolated water storage structures with simple manufacture