Abstract
This study aims to simulate using water resources in the Jereweh watershed to meet irrigation water needs. From the calculation results of the analysis of the annual average water availability at the Lang Desa Dam of 0.96 m 3 /sec (29.98 mln m 3 ), the Tiu Bangkemah Embung of 1.53 m 3 /sec (47.60 mln m 3 ), and the Murus I Embung of 0.06 m 3 /sec (1.79 million m 3 ). The optimal allocation of water based on the water balance in the Jereweh watershed system is as follows: cropping pattern MT- I: rice (100%); MT-II: 30% rice + secondary crops (70%); MT-III: beo with a planting intensity of 200%. It was early planting November I, type of secondary crops: corn with reliability > 80%, namely Lang Desa Weir 88%, Tiu Bangkemah Embung 92% and Murus I Dam 92%. The total area served is 650 ha: Lang Desa Dam - 300 ha, the Tiu Bangkemah Embung - 300 ha, Murus I Embung - 50 ha. From the simulation results consists, it is necessary to add water reservoirs (dams) to maximize the performance of existing natural resources facilities in the Jereweh watershed system (there is a deficit of 150 ha). From the results, it can be seen that the value of benefits obtained in the existing condition is Rp. 6,840 bln, while the value of benefits received after the simulation is Rp. 14,82 bln so that the difference in the value of benefits is Rp. 7,98 bln.