The Marina Reservoir (Chinese: 濱海蓄水池) is a reservoir in Marina Bay, Singapore formed in 2008 from the damming of the mouth of the Kallang Basin. With the completion of the Marina Barrage on October 30, 2008, the reservoir, which contained mainly salt water, became freshwater and started operations at 7 pm on November 20, 2010 after a process of natural desalination, when excess water was released out to the sea after heavy rains. The reservoir will provide 10% of the island's water needs.
The catchment area that is resulted from the forming of the reservoir is about one-sixth the land size of Singapore, the largest of all the reservoirs, and two of the island's major rivers - Singapore River, Kallang River and Geylang River, as well as Rochor River, a tributary of the Kallang River flow into it. This is a competition venue for the 2010 Youth Olympic Games, where the sports are canoeing and rowing.
With the recent completion of the Marina Barrage in 2008, the newly created Marina Reservoir is a choice venue for a wide range of water-based activities including hosting the canoe-kayak and rowing events. The area includes a one-kilometre straight race course for canoeing and rowing activities. The Singapore Canoe Marathon 2009 was staged at the Marina Reservoir in January 2009.