Two men fished off the end of a Bayview pier at sunset on a Saturday evening.  Just a few feet away a large yellow sign, warning “Underground Sewer Crossing,” served as a perch for gulls. The T-Third clattered across a grooved metal bridge over the water.  On the opposite bank, a few kids skateboarded around a windswept concrete promenade.  The bay end of Islais Creek at sundown is a tranquil spot in an otherwise chaotic neighborhood. But perhaps not for much longer.

One Hundred Years of Degradation

Islais Creek is one of San Francisco’s few remaining natural water bodies.  The creek originates in Glen Canyon Park, just south of Twin Peaks.  Few San Franciscans have seen the exact spot where the creek emerges from the hillside; the underbrush is too thick for a person to penetrate, though the creek’s gurgle can be heard from nearby trails.  A number of plants and animals rely on the creek for sustenance, including great horned owls, red-tailed hawks, and mission and blue butterflies.  Just downstream from the creek’s underground headwaters, the vegetation thins out, allowing hikers to stroll along its banks accompanied by flowers and trees. Gazing up from the canyon floor, passersby can forget that they’re in a city.

At the park’s southern end, the creek spills into a crusty metal grate, vanishing from sight, until it emerges roughly four miles away in the Islais Creek Channel, a block south of Cesar Chavez. A century ago, the entire creek was above ground, with kids playing in the water and boats navigating around Bernal Heights. Today the water flows through decades-old underground pipes.  Only an outline of the creek remains; Highway 280 follows the path the water once took.  

Before the arrival of settlers, the Muwekma Ohlone made use of the creek.  Shellfish were plentiful, the water was clean enough to drink, and along the banks grew islay berries, which lent the water its name.  Islais Creek is the only site in San Francisco to bear a name derived from the language of its prior human inhabitants.    

In the late-1800s what’s now called Bayview emerged as Butchertown, an epicenter of slaughterhouses.  The creek was used to carry offal into the bay.  Soon the water became polluted. Landfill and heavy industries followed.  Islais Creek became narrower and filthier. By the 1950s, automobile scrap yards littered the area and the City was releasing untreated sewage into the channel, which had become known colloquially as Shit Creek.  Two hundred years ago the creek’s mouth was two miles wide. Now it’s roughly the length of a city block.