Water supply, which comes under the jurisdiction of the Penang state government, is wholly managed by the Penang Water Supply Corporation (PBAPP). The state enjoys the lowest domestic water tariff in Malaysia, at RM0.32 per 1,000 litres. Penang's water supply is obtained from several sources, namely the Air Itam Dam, Teluk Bahang Dam, Mengkuang Dam, Bukit Panchor Dam, Berapit Dam, Cherok Tok Kun Dam, the Guillemard Reservoir, the Penang Botanic Gardens and the Muda River. The latter, which forms Penang's northern border with Kedah, provides up to 80% of Penang's water supply.