The Semenyih Treatment Plant draws its raw water from Sg. Semenyih. Flow in the river is regulated by the Semenyih impounding reservoir. During the prolonged drought in 1997, raw water storage in Semenyih impounding reservoir was severely depleted to very critical level and unable to augment the low flow at Sg. Semenyih Intake to enable adequate abstraction for public water supply.
The production of Semenyih Water Treatment Plant was significantly reduced and water rationing was imposed for about 5 months, causing great difficulties and inconveniences to the affected supply area in Klang Valley. In order to augment the raw water deficit at the Semenyih Intake, it was proposed that numerous disused mining ponds (located a short distance downstream of the Sg. Semenyih Intake) be developed and connected in series to act collectively as regulating reservoir/bunded storage to regulate the flow at the Sg. Semenyih Intake. The yield of Sg. Semenyih will be increased by 70 Mld (15 Mgd)
Asia Baru Construction Sdn. Bhd. which is well known and experienced in fast-track water supply projects was chosen to lead the Premier Ayer-Asia Baru Consortium to undertake the project on turnkey basis. The works proposed by the Consortium include :-