Performance assessment of reservoir storage capacity

Abstract

This research intends to assess the performance of reservoir capacity. The performance of reservoir capacity indicates the reliability in guaranteeing the water supply need. However, this assessment of reservoir storage capacity is based on the variability coefficient of hydrology conditions. The methodology consists of data collecting that includes the historical discharge that is used for analyzing the variation coefficient of yearly discharge (Cv), water need based on the yearly discharge ratio (D), and storage capacity over the year (Ka). The performance of reservoir storage capacity uses the regression equation of Mc Mahon and Adeloye. The result shows that Indonesia’s reservoir storage capacity is well performing only for fulfilling the water need demand of about 0.0001 to 0.15 of yearly average discharge. However, the negative NSE value is obtained for water demand about 0.2 until 0.55 of yearly average discharge. It shows that the storage capacity observed is under-estimate if it is for supplying the water need demand with a ratio of more than 0.2 of yearly average discharge. This research result is hoped to predict the feasibility of reservoir storage capacity. In addition, it can be used as a reference in assessing the performance of multipurpose reservoir storage capacity as the base of accurate decision taking in planning reservoir storage capacity and reservoir utilization. Then, it is the base of decision taking in designing the dimensions of dam complementary buildings.