Sungai Selangor Water Supply Scheme. Intake, raw water pumping mains, water treatment plant and associated. The damansara reservoir and treatment works, completed in 1966,was our first job. "the development of this water supply scheme is crucial as sungai selangor scheme is currently the only source of raw water supply to the . The selangor water works provides water supply to the state of selangor as well as the federal territories of kuala lumpur and putrajaya in malaysia.