The Sungai Selangor Dam is part of the overall Sungai Selangor Water Supply Scheme that functions to regulate the flow in Sungai Selangor. This is to enable sufficient amounts of raw water to be reliably abstracted at the Rasa and Bukit Badong plant intake points.

197 square kilometres of the catchment area upstream of the dam has been gazetted as a forest and water catchment reserve, assuring protection from any development.

This protects the water source from any development that may have adverse effect on the quality of raw water. This in turn ensures raw water at the abstraction points continue to be of standard quality viable for treatment.