PUB, Singapore's National Water Agency | 21,078 followers on LinkedIn. PUB is a statutory board under the Ministry of Sustainability and the Environment (MSE) that oversees water issues in an integrated way. PUB's mission is to ensure Singapore has a reliable and secure water supply, and protect it from inland and coastal flooding. Through the Four National Taps (local catchment water, imported water, NEWater, desalinated water), PUB has ensured a diversified and sustainable supply of water for Singapore.