However, the reservoir's a day were still insufficient to meet demand. Water was pumped into the reservoir from the upper section of Kallang River, one of the island's bigger sources of fresh water. Other fresh water supplies – Lower Peirce Reservoir and Seletar Reservoir – were completed in 1912 and 1920 respectively. However, the government realised that Singapore would not be able to meet its own fresh water needs. In 1927, a water treaty was signed with the Sultan of Johor and Singapore started receiving treated water from the Gunong Pulai water project Johor in 1930.