Study of development planning evaluation on the utilization of kali baru river basin with ribasim decision support system

This paper intends to evaluate the development planning of river basin utilization as the decision support system of water manager. There are two problems which are especially evaluated due to by making effort and without making effort conditions. The methodology consists of water ballance simulation approach for each condition that is analyzed by using DSS Ribasim software. Result shows that the development effort of 3 reservoirs are not significant if it is related with the increasing on the whole production yields of paddy and second crop in the river basin level. Evaluation result indicates as follow: water usage is in the range of 0.78% - 0.95%; the increasing of water allocation usage is in the range of 0.002 m³/s – 0.009 m³/s; the increasing of water allocation is in the range of 1.87 m³/ha – 6.10 m³/ha; the increasing of maximum paddy production is 130 ton per-year and the maximum second crop production is 1,346 ton per-year. In addition, the increasing of income is in the range of Rp. 0.196 milyards – Rp. 3.086 milyards per-year, the water deficit is less and less in the range of 0.06 millions m³ –0.285