Climate change impact to dam Operation, case study of Darma Dam, West Java

Darma Dam is located in the upstream of Cisanggarung River, Kuningan Regency, West Java Province. Darma Dam construction dated from about 1922. Indonesian government continued the construction and began operating in 1962. With effective storage of about 40 million m³, Darma Dam provides water for about 22 thousand irrigation areas and bulk water for several cities and regencies. Several problems encountered in Darma Dam operation and water management are 1) increasing water demand from domestic and industrial sectors, and 2) high inflow variation during the dry and wet season, resulting in a large amount of water spill from the dam spillway. This paper addressed the impact of climate change on the inflow variation of Darma Dam in the dry and wet seasons. Further analysis shows average water spills from the spillway during the wet season may increase from about 12 million m³/year in the present condition to about 20 million m³/year in 2020-2050, while the average water volume during the dry season may reduce from 22.5 million m³ in the present condition to about 20.7 million m³ in 2020-2050. This study suggests that dam operation need adjustment in the future as part of adaptation to climate change.