OUR FUTURE CITY
Is It Finally Time to Daylight Islais Creek?
Talked about for years, restoration of San Francisco’s buried waterway has more urgency in an era of accelerated climate change.
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Islais Creek: It’s a sprawling and lush ecological hot zone, a wellspring for environmental education and cultural heritage, a natural flood-control system along San Francisco’s southeast shoreline in an age of climate change and rising sea levels — and even an economic boon for the city.
Or at least it could be.
Instead, however, most of the creek has been forced underground into San Francisco’s sewer system, where it remains out of sight, except when it bursts its bonds during the rainy season, and floods Alemany Boulevard at its intersections with Highway 101 and I-280.
Problem or opportunity?
For more than a century, Islais Creek was considered a problem: What’s to be done with all this water washing down from the hills into the Bay, causing trouble along the way? Burying it was the simple solution.
But the conversation has changed in recent years, as San Francisco’s Planning Department and Public Utilities Commission look ahead at the impact of accelerating climate change on the city’s southeastern waterfront — home to light industry, much of the city’s food distribution system, and major transportation corridors.
Now, Islais Creek, and its abundant, seasonal flows, is increasingly recognized not so much as a problem, but rather an opportunity.
“What’s special about Islais,” says Robin Abad Ocubillo, a senior planner at the Planning Department, “is that it runs a historic path through so many different neighborhoods, land uses, and social environments. It can be a backbone that can knit together neighborhoods.”
It could even boost civic engagement. “The literature shows that a person’s sense of environmental stewardship and even citizenship can be affected by their degree of contact with green space, parklands, creeks and rivers,” says Ocubillo.
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Named for the sweet, dark-red islay (or hollyleaf) cherries that used to line its banks, Islais Creek is now recognized as one of the city’s most significant natural resources — one that is being prolifically wasted. Changing that is going to take time, but plenty of folks would like to see it happen, and they have no shortage of ideas.
In fact, new projects are underway that might point the way, someday, to more of Islais Creek seeing the sun.
A life underground
The northern source of Islais Creek seeps out of Twin Peaks and its misty southern slopes, and runs a brief, unencumbered course through the monkeyflowers and willow thickets of Glen Canyon Park. (For The Frisc’s guide to a day well spent in the park, click here.)
“We’ve had our eye on Islais for a long time.”
— Sarah Minick, San Francisco Public Utilities Commission
But at the mouth of the canyon, Islais Creek is forced into concrete pipe to run east under neighborhoods, car-choked highway interchanges, and the city’s southeastern industrial flatlands, until it emerges back into daylight directly under I-280 between Cesar Chavez and Evans Avenue as a muddy channel into the Bay. It’s the outflow of 5,000 acres of prime San Francisco watershed, dumped expediently into the Bay like mop water down the sewer.
Underground, it picks up considerable volume from its southern branch, fed by runoff from the hills along the San Francisco-Daly City border, then more from its tributary Precita Creek, which it joins, still underground, near Cesar Chavez and Evans between the 101 and 280 freeways.
For thousands of years prior to colonization, the creek’s interface with the Bay was a complex of marshes, ponds, sloughs, sandbars, and beaches that encompassed around two miles of shoreline.
Into the early 20th century, it was also a productive ecosystem. You could even fish for smelt, perch, and bass, despite the wetlands’ transformation into a “malodorous” trough for urban refuse of all sorts, including animal carcasses from the old Butchertown slaughterhouses.
After the 1906 earthquake and fire, the wetlands and creekbed were filled in with debris, and Islais Creek became lost — or at least hidden — history.
But for those who have been paying attention, the creek has always been visible.
Engineering the opportunity
“We’ve had our eye on Islais for a long time,” says Sarah Minick, a planning manager at the San Francisco Public Utilities Commission.
Daylighting the creek is easy to talk about, but Minick points out that it’s not a good idea to just bring to the surface whatever’s flowing through the sewer system, which combines Islais Creek water with storm runoff and the effluvia that gets flushed down toilets and washed down sinks.
To make daylighting possible, she says, the stormwater would have to be separated from the wastewater. And because Islais Creek drains the largest watershed in San Francisco, re-engineering its flow would mean tearing up asphalt and concrete and upgrading the sewer system in dozens of neighborhoods across the Mission, Noe Valley, Potrero, the Bayview and more.
It would be enormously expensive and disruptive. Yet, at some point, the antiquated system needs to be upgraded, piece by piece. The costs come to bear with the flooding that accompanies every heavy rainstorm (most recently last month).
Meanwhile, the PUC and the Recreation and Parks Department are running a modest daylighting test of their own with Yosemite Creek in McLaren Park. (Design and planning will take a couple years before any dirt is moved.) Success with Yosemite, says Minick, would amount to “an exciting precedent, and would enable a scale-up to Islais Creek.”
Islais Creek will never return to its precolonial state while San Francisco remains a populous urban center, but the possibility of some sort of redesign is at least now on the table.
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The Planning Department, charged with long-term vision, has recently launched an Islais Creek Adaptation Strategy, an ambitious, multi-year, public planning discussion that will encompass transportation, shoreline access, ecological habitat, and what the department calls the “resiliency” of adjoining neighborhoods.
This planning process is also being coordinated with the Public Utility Commission’s long-term plans to upgrade San Francisco’s water and sewer systems.
Hyper-creek and rain gardens
What could a restored Islais Creek look like?
At the technocratic end of the spectrum is the Islais Hyper-Creek. In this vision, the creek’s southern bank as it enters the Bay is a “soft shoreline” with beaches, recreational facilities, and water clean enough for swimming. On the north bank would be small businesses, light industry, and, because this is San Francisco, an “innovation cove” that includes experiments with “resilient floating architecture.”
Upstream, the project envisions a riverfront park, a reconfigured Alemany Farmers Market, and restored wetlands.
The hyper-creek was one of the featured proposals of last year’s Resilient by Design challenge, a Rockefeller Foundation-funded program to develop new ideas to help Bay Area municipalities withstand the impacts of climate change, earthquakes, and other catastrophic events.
Landscape architect and artist Bonnie Sherk, whose public advocacy previously helped create Potrero Del Sol Park, also wants to revive the watershed further upstream. “Just dealing with the outflow at Third Street isn’t enough,” she says.
Sherk’s vision is of “blue-green” parks farther west, in neighborhoods such as the Excelsior and Crocker-Amazon, where a daylit creek and water features would catch stormwater before it enters the sewer system, and use that surface flow for other purposes. As a proof of concept, and equipped with a grant from the California Natural Resources Agency, she plans to install a series of “rain gardens” that would sustain native plants along Seneca Avenue near Balboa Park, where Islais Creek’s southern branch runs below the surface.
Somewhere between the hyper-creek and Sherk’s blue-green parks is a proposal by former PUC program manager Rosey Jencks and the landscape architect Patricia Algara. Like Sherk, they want to store and reuse rainwater, capturing it in landscaping and cisterns under homes, institutions, retrofitted parks, and sports fields. They also bow to the inevitable: Not all the water can be captured or diverted, so they propose a network of “floodable lands” along key segments of a daylighted Islais Creek to accommodate seasonal surges of rainwater and tides.
Jencks and Algara also acknowledge some property in the area, one of the city’s most vulnerable, will have to be abandoned. The waters will not be kept at bay. In those cases, they ask, why not convert the parcels into wetlands or public space designed to accommodate evolving Islais flows?
Running out of time?
These ideas are inspiring, but will they make a difference?
Joel Pomerantz, an environmental educator and the author of the “Seep City” map of San Francisco’s waterways and watersheds, isn’t so sure. “The climate is changing faster than our model is accommodating,” he says, and worries that “the protections we put up will probably be obsolete in the time it takes to construct them.”
That’s not to say he, or anyone else concerned with San Francisco’s future, doesn’t want to think big.
“I do love the idea of discussing optimistically how wetlands can be created,” he says, “and how creeks can be daylighted and engineered,” because it’s part of creating a healthy human relationship with the natural world.
Whether a given daylighting project succeeds or fails is therefore not quite the point.
What’s really at stake is whether we can learn to live sustainably in a Bay Area that will, over the next 50 to 100 years, become a different place from the one we know and love today.
Josh Wilson, a journalist and editor in San Francisco, is also the publisher of newsdaylighter.com.
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