Indonesia's Three Largest Reservoirs, All Located on Java

Indonesia boasts numerous giant reservoirs that play a vital role in irrigation, power generation, flood control, and raw water supply. The three largest reservoirs in Indonesia are currently all located on Java Island. These three dams are spread across West Java and Banten, with enormous storage capacities and strategic benefits for millions of people. For information, a dam is a physical structure (concrete wall/earth embankment) built to hold back the flow of a river, while a reservoir is a massive body of water or artificial lake formed behind the dam as a result of containment. Here is a list of Indonesia’s largest reservoirs compiled from the Directorate General of Water Resources, Ministry of Public Works website: The largest dam in Indonesia is the Ir. H. Djuanda Dam, better known as the Jatiluhur Dam. This dam is located in Jatiluhur Subdistrict, Purwakarta Regency, West Java. The Jatiluhur Dam has a reservoir surface area of 8,300 hectares with a storage capacity of 2.44 billion cubic metres. Its functions are highly vital, serving as a power plant with a capacity of 187.5 MW for the Java-Bali system. In addition, this dam irrigates the Jatiluhur Irrigation Area covering 242,000 hectares. With such extensive irrigation coverage, Jatiluhur serves as one of the main pillars of national food security. The second largest reservoir in Indonesia is the Jatigede Dam in Sumedang Regency, West Java. The Jatigede Reservoir has a surface area of approximately 3,900 to 4,891 hectares. This dam was built to utilise the water potential of the Cimanuk River, which has an average flow of 4.3 billion cubic metres per year. The Jatigede Reservoir can irrigate an area of around 90,000 hectares. Its presence also aids in water resource management in the Cimanuk-Cisanggarung River Basin, which spans West Java to Central Java. The third largest dam in Indonesia is the Karian Dam, located in Pasirtanjung Village, Rangkasbitung Subdistrict, Lebak Regency, Banten. This dam is one of the largest dam projects built in recent years. The Karian Dam has a reservoir surface area of about 1,740 hectares with a total storage volume of 314 million cubic metres of water. With that capacity, this dam ranks third largest in Indonesia. Its construction took place from 2015 to 2024. The dam is designed to provide numerous benefits, particularly as a supplier of raw water for households, cities, and industry at 9.1 cubic metres per second. This water supply is intended for Lebak Regency, Tangerang City, Tangerang Regency, South Tangerang City, and parts of DKI Jakarta through the Karian-Serpong Conveyance System (KSCS).