Sunset Reservoir is one of three terminal reservoirs in the Regional Water System in San Francisco, California. The reservoir is the city's largest reservoir and is located in the Sunset District at 24th Avenue and Ortega Street, is owned and maintained by the San Francisco Public Utilities Commission. Completed in 1960, the subterranean reservoir was constructed as an 11-acre (4.5 ha), 1,000 by 500 feet (300 m × 150 m), concrete basin, now containing 720 floor-to-ceiling columns.