Twenty-five thousand solar panels gleam on the Sunset Reservoir North Basin’s roof. Imagine a shimmering sea of photovoltaic cells. This isn’t just any reservoir. It’s San Francisco’s largest. Nestled in the Sunset District at 24th Avenue and Ortega Street it’s a vital part of the city’s infrastructure.
Completed in 1960 this subterranean marvel is an 11-acre concrete basin. It’s 1000 feet by 500 feet. Picture that size. 720 floor-to-ceiling columns support the roof. They hold back the weight of the water and the solar panels above. This is a truly impressive feat of engineering. The reservoir holds a massive 270 acre-feet of water. That’s enough to keep a large part of the city supplied. The average daily flow is substantial. Forty-six acre-feet are pumped in and out through large pipes.
The Sunset Reservoir North Basin has undergone significant upgrades. Seismic rehabilitation was vital. Soil dam embankments were stabilized. The walls and roof were retrofitted with seismic joints shear walls and struts. Foundations were improved. This ensured that the reservoir would withstand even the strongest earthquakes. Further general rehabilitation included repairing concrete and replacing lining materials. Security fencing and landscaping were also improved.
But the story doesn’t end there. The Sunset Reservoir Solar Project is remarkable. It transformed the reservoir roof into a giant solar farm. The five-megawatt plant more than tripled San Francisco’s solar generation capacity. That’s a significant increase in renewable energy production. This project opened in December 2010 during a ceremony led by then-Mayor Gavin Newsom. The clean energy powers public buses San Francisco International Airport and city health clinics.
So next time you drive past Sunset Reservoir North Basin think about the engineering marvel and the environmental responsibility represented there. You are standing before a testament to human ingenuity and environmental sustainability a hidden gem within the heart of the city. The reservoir ensures the city’s water supply and produces clean energy a double benefit for San Francisco.