Despite having over 20% of the freshwater reserves of Asia, Indonesia has great difficulty in providing potable water as well as freshwater supplies to meet the demands of society, industry, and agricultural producers. Water shortages are especially acute during the dry season, particularly in urban areas, and total economic losses attributable to limited access to safe water and sanitation were conservatively estimated in 2009 by the World Bank to be 2% annually. Poor water quality can cause outbreaks of major diseases, posing an additional stressor to already vulnerable populations. Moreover, agricultural run-off, inadequate storage capacity, and fertilizer and pesticide use for agricultural production serve to exacerbate existing problems of water scarcity and pollution. While shallow groundwater supplies may meet demand for household consumption, water quality and quantity fluctuate widely, especially in the dry season. Industries, on the other hand, resort to deep groundwater resources to meet their larger-scale needs; this can consequently cause land subsidence, leaving large areas vulnerable to flood and salt-water intrusion.
This section provides insights into projected climate change impacts on various hydrological indicators.