The Secret Rivers Beneath Our Feet: Hidden Waterways of San Francisco

You’ve walked over them a thousand times without knowing. Maybe you’ve even parked your car above one. Beneath San Francisco’s grid of hills and homes, a forgotten web of streams and creeks still winds its way through the city—ghost waters of the natural world that predated cable cars and sourdough starters.

Once upon a time (say, 1850), San Francisco was laced with freshwater creeks that tumbled from Twin Peaks down to the Bay. There was Islais Creek, trickling through what’s now the industrial flats of Bayview. Yosemite Creek flowed near where 3rd Street rumbles today. And the mighty (if now subterranean) Mission Creek once carried water—and cargo—through the heart of what’s now Mission Bay.

But those weren’t the only ones. Lobos Creek still flows visibly near Baker Beach, supplying fresh water to the Presidio. Along 7th Avenue, especially in the Inner Sunset District, remnants of an old creek surfaces after storms—hinting at waterways that once drained the western slopes. Pine Lake and Lake Merced are the last visible vestiges of a much larger system that once saturated the southwestern part of the city.

As San Francisco boomed, we buried them. Paved over them. Built Victorians and boulevards on top of them. But they didn’t disappear. On rainy days, the ghosts of these waterways whisper back—making puddles in funny places, nudging sidewalks into wavy mosaics and sending homeowners to the hardware store for sandbags.

So next time you're walking along 18th Street in the Mission or navigating the wiggles of Glen Park, take a moment to wonder what’s flowing quietly beneath you. The city may seem like concrete and commerce, but underneath, it's still wild with water.

For a map of San Francisco’s old waterways, go to https://seepcity.org/.