The Reason Why Sunset Reservoir is Half-Empty

For the first time since 2016, half of the largest in-City drinking water reservoir is empty of water.

Inside Sunset Reservoir’s South Basin.

Nestled in the City’s quiet Sunset District on the west side, Sunset Reservoir’s two basins serve water to 48% percent of San Francisco’s population. It is one of 10 drinking water reservoirs located in the City. The SFPUC regularly empties these reservoirs of water to conduct inspection and maintenance work. This year it was Sunset Reservoir South Basin’s turn.

Inside Sunset Reservoir’s South Basin.

Since emptying out the South Basin two months ago, SFPUC crews have been cleaning and inspecting the interior structure. They will begin replacing some of the aging valves before disinfecting and putting the basin back in service later this summer. This work helps to keep San Francisco’s water system functioning and safe.

Inside Sunset Reservoir’s South Basin.

Sunset Reservoir’s North and South basins hold a combined 176.7 million gallons of water.  SFPUC crews will refill the reservoir basin slowly in stages, which could take about a week or two.