Discovery Bay Reservoir, Water reservoir in Discovery Bay, Hong Kong.

Discovery Bay Reservoir is a water storage facility in the private residential development of Discovery Bay. The basin collects rainwater and occupies a landscape that stretches several hundred meters, with planted banks and public pathways around it.

The facility was built in the early 1980s to supply drinking water to the new Discovery Bay residential development. In 2000, the water authority switched to sourcing water from outside the area, and the reservoir took on other functions.

The reservoir's name comes from Discovery Bay, the private residential estate built by Hong Kong Resort Company, which funded the HK$100 million dam. Residents long prized the water quality; when the Water Supplies Department took over supply in December 2000, many opposed the change. The reservoir now serves flushing and flower irrigation.

The reservoir is private infrastructure of the Discovery Bay residential development and is not open to the public; there are no fishing or visitor activities. Since December 2000 its water has come from Tai Lam Chung Reservoir through a pipeline inside the Discovery Bay Tunnel, and the reservoir itself is used only for toilet flushing and watering flowers.

The reservoir served as a drinking water source for thousands of residents for over 20 years before it completely changed its purpose. Today the water is used mainly for practical purposes like toilet flushing and irrigation, marking a major shift in its role for the community.