Author(s): Fahmi Hidayat, Pitojo Tri Juwono, Agus Suharyanto, Alwafi Pujiraharjo, Djoko Legono, Dian Sisinggih, Firman Sarifudin Effendi
Linked Author(s): Fahmi Hidayat
Keywords: Reservoir sedimentation, sediment flushing, efficiency, environmentally friendly, Wlingi and Lodoyo reservoirs.
Abstract: This paper addresses the sedimentation issues in Wlingi and Lodoyo reservoirs, in the Brantas River basin, Indonesia, and the efficient and environmentally sediment flushing operations in both reservoirs which are designed to achieve their long-term use. The sedimentation problem in Wlingi and Lodoyo reservoirs, is very severe due to sediment input from the recurrent eruptions of Mt. Kelud, one of the most active volcanoes in Indonesia. The latest eruption of Mt. Kelud occurred on 13 February 2014. After the eruption, the effective storage capacity of Wlingi and Lodoyo reservoirs decreased dramatically to 1. 01 MCM and 1. 33 MCM, respectively. To cope with the sedimentation problem, diverse sediment management strategies have been applied in these reservoirs and their catchments since the 1990 eruption of Mt. Kelud. One of the strategies is to recover the reservoirs� storage capacity by hydraulic flushing to remove accumulated sediment deposits from the reservoirs. Sediment flushing operation in Wlingi and Lodoyo reservoirs is a paradox. It is expected to remove accumulated sediment as much as possible from both reservoirs by consuming as little as possible of water in order to have a high flushing efficiency. On the other side, high efficiency flushing operation will cause adverse environmental impacts in the downstream water quality. Based on the observations done during sediment flushing operations, the impacts on water quality and aquatic organisms are considered to be significant for several days. The sediment flushing in Wlingi and Lodoyo reservoirs caused extremely high concentration of suspended solids in the downstream of both reservoirs
Year: 2017