Bali is a province of Indonesia and the westernmost of the Lesser Sunda Islands. East of Java and west of Lombok, the province includes the island of Bali and a few smaller neighbouring islands, notably Nusa Penida, Nusa Lembongan, and Nusa Ceningan.
Over-exploitation by the tourist industry has led to 200 out of 400 rivers on the island drying up. Research suggests that the southern part of Bali would face a water shortage. To ease the shortage, the central government plans to build a water catchment and processing facility at Petanu River in Gianyar. The 300 litres capacity of water per second will be channelled to Denpasar, Badung and Gianyar in 2013.
A 2010 Environment Ministry report on its environmental quality index gave Bali a score of 99.65, which was the highest score of Indonesia's 33 provinces. The score considers the level of total suspended solids, dissolved oxygen, and chemical oxygen demand in water.