A discharge estimation model using a spatial correlation method in Cipanunjang-Cileunca Reservoir, Bandung District, West Java Province

Cipanunjang-Cileunca reservoir is one of the raw water sources for the Drinking Water Supply System of Bandung City and Bandung District. The total raw water need for both area is 1.66 m 3 /s. It is known that discharge data estimation is essential for the successful management of the reservoir. This study estimate the future discharge of the Cipanunjang-Cileunca Reservoir using a spatial correlation method, also known as the continuous method. Before the discharge was estimated, the mainstay discharge was first calculated in each reservoir. We found that the mainstay discharge for the raw water in Cipanunjang Reservoir was 0.86 m 3 /s, while in Cileunca Reservoir was 0.34 m 3 /s. This study also calculated the sufficient reservoir volume using discharge data from 2000 to 2017, and found that there was a decrease of reservoir volume: from 22 million m 3 to 18.7 million m 3 at Cipanunjang Reservoir, and from 11 million m 3 to 9.5 million m 3 at Cileunca Reservoir. Discharge estimation using a continuous method showed a correlation between historic discharges, which was 0.87 for Cipanunjang Reservoir and 0.83 for Cileunca Reservoir. This shows that the discharge estimation model using a continuous method, which had a value close to 1, could estimate future discharge.