Penentuan Initial Elevation untuk Mendukung Operasi Early Release Bendungan Sadawarna

Abstract

Modifications of Sadawarna Dam include the addition of a sluice gate that is placed on the right side of the spillway which functions as an early release facility along with an intake to lower the reservoir water level before the flood comes. Implementation of early release on reservoir routing requires an initial elevation that is different from the initial elevation in general. The aim of this research is to determine the new initial elevation to support early release operations for the Sadawarna Reservoir. This research was conducted by calculating return flood discharge and flood routing in reservoir with 3 (three) scenarios of initial elevation. The method used for analysis of return flood discharge is SCS (Soil Conservation Service). The reservoir routing method uses level pool routing with the HEC-HMS application. Initial elevation is determined by 3 (three) scenarios that started from initial elevation +75,25 masl, +77,00 masl, and +78,50 masl. The results of 3 (three) scenarios showed that the optimal initial elevation that can be used in early release operations is at an elevation of +77,00 masl. The results of the reservoir flood routing simulation with initial elevation resulted reduction flood discharge up to return period of 50 years and resulted in the fastest reservoir water level recovery