Optimal system operation of the drops-cascading Konto system, Indonesia

A cascading multiple-use water system in the Konto River Basin, Indonesia, has been examined to assess the cumulative benefits of water uses where water is sequentially used in three hydropower plants and then in an irrigation system from an upstream reservoir. Using a hydro-economic modeling, optimal water allocation among the users was explored, considering appropriate environmental flows (EFs) as well. Tradeoffs between benefit maximization and environmental protection at the basin scale benefits due to different provisions of EFs were examined. Estimates indicate that the current operation mode, not considering EF in the mainstream of the Konto, generates an annual maximum benefit of US$ 16.281 million from the perspective of direct water uses; however, ensuring environmental water requirements in the current operation mode will cost about US$ 1.067 million annually. Such analyses will help in running the Konto system in a sustainable pattern and in other places with similar conditions.