Sea Breach—Bringing back the Bay

10 years and $18 million later, the Sonoma Land Trust tore open a levy and let San Francisco Bay run free.

Story & Photos
David Bolling

The water volume of San Francisco Bay at mean sea level has been computed as 6.165 billion cubic meters. One cubic meter equals roughly 264 gallons. Feel free to do the math.

On October 25, under a brilliant blue sky just south of Lakeville Highway, some 300 people gathered on a levee keeping all that water at bay, and cheered as a giant Hyundai excavator extended a scoop bucket into the mounded dirt and tore it open. What followed was a trickle that quickly became a rivulet that transformed almost instantly into a gusher of green water that evolved into an ever-widening waterfall as San Francisco Bay surged over the eroding levee, dropping six feet into the waiting embrace of a 1,000-acre plot of former farmland, diked and drained some 140 years ago.Bay Breach - wide

Breaching of the dike—dubbed “Sea Change” by the Sonoma Land Trust which oversaw and engineered the project over the course of a decade—had about it the feel of a titanic moment in time.

The raw power of the impatient bay water rushing toward hydrologic balance, filling a vast depression 6 or 7 feet below sea level, seemed not unlike the unleashing of a caged beast. It felt raw, wild and primordial. It also felt historic, because it was.

San Francisco Bay has lost nearly 90 percent of its historic wetland, a buffer of inestimable value, especially as climate change threatens to raise ocean levels at least 15 inches by 2050 and, climate scientists gauge, by as much as 5 feet by 2100. That would put saltwater onto and over the railroad tracks along Highway 37 and, in fact, well over the highway itself. The problem is exacerbated by the presence of vast tracts of sub-sea-level land, much of it former peat soil, that naturally subsided when it was “reclaimed” more than a century ago for farmland.

Options for protecting the multi-billion-dollar infrastructure ringing the bay are limited—consisting primarily of spectacularly expensive seawalls on the one hand or the expansion of tidal marshes, like those that still ring parts of the North Bay.

The marshes, if allowed and encouraged to expand, can keep storm surge and, to some extent, sea-level rise from threatening developed property further inland. As the marshes are given the opportunity to re-establish, they capture silt from the bay and naturally begin to rise above the level of the water. The resulting wetlands also serve as vital habitat for shorebirds and a wide variety of creatures occupying the interface between sea and land. That includes two notably endangered species—the salt marsh harvest mouse and the California clapper rail.

Julian Meisler, the Land Trust’s Baylands manager, told the Sea Change gathering at a celebratory brunch on the edge of the site, “The tide has begun to turn. We will witness the return of the wetlands to nearly 1,000 acres and the map of San Francisco Bay will have to be redrawn. . . .  We are now working with nature, not against it, to rebuild what was lost.”Bay Breach - hiking to levee

Putting the pieces together took some 10 years and began with what some feared would be an ecological debacle—plans by the Federated Indians of Graton Rancheria to build a nearly billion-dollar hotel and casino complex on the former Sears Point Ranch site. The proposal, led by controversial tribal chairman Greg Sarris, ran into a wall of opposition, including a rebuff from Sonoma, Marin, Napa and Solano County supervisors, U.S. Senator Dianne Feinstein, several members of Congress and a citizens campaign called “Cows, Not Casinos.”

By the end of 2003, Sarris and his tribe threw in the towel and dramatically reversed course by generously donating their $4.5 million down payment on the bay-front property to the Land Trust, along with $75,000 in cash to initiate the necessary studies.

Completing purchase of the property for the $18-million project took until 2005, and another decade was devoted to reshaping levees around the railroad right-of-way, dredging channels for entrance and exit of bay tides, building dirt mounds throughout the basin to be flooded for wave suppression and plant growth, perfecting plans and studies and designing visitor resources.

The 1,000-acre restored salt marsh will be paired with another 1,300 acres of seasonal ponds, riparian drainages and grasslands. The Land Trust project is contiguous with the Sonoma Baylands, a string of former salt ponds and tidal marsh also in the process of incremental restoration. Together, the projects create an arc of restored and recovering wetlands reaching from the Petaluma River all the way to Mare Island on the edge of Vallejo.Austin Payne

Public access to the property will soon include a new 2.5 mile section of the San Francisco Bay Trail, set atop the project’s redrawn levee, and a kayak launch ramp giving access to the bay and the emerging wetlands. Another 1.3 miles of new inland trail is laid out from the site’s new parking lot, leading to the Land Trust’s Baylands Center.

Numerous public and private agencies had a hand in creating the restoration, prominently including Ducks Unlimited, the U.S. Fish and Wildlife Service, the California Department of Fish and Wildlife, the California Department of Natural Resources, the U.S. Environmental Protection Agency, the San Francisco Bay National Wildlife Refuge, Congressman Mike Thompson, D- St. Helena, and the Federated Indians of Graton Rancheria.

Complete restoration of the salt marsh must await the steady deposition of silt from bay waters coursing through the site and the incremental growth of island clumps of pickleweed and other brackish-water plants. Meisler said that process will take at least 20 years.Julian Meisler

Officials from the Sonoma Land Trust say they expect public access to be completed early in 2016, but visitors can already make their way out on the new levee to stand above the flooded site and watch the slow transformation unfold.

To get there, visitors can take Highway 37 from Sears Point west to Lakeville Highway. At the Lakeville stoplight there is a left-turn lane onto the aptly named Reclamation Road that leads directly to the site.

For more information about access and activities, contact the Sonoma Land Trust at 707.526.6930, or go to sonomalandtrust.org, where you can also find a stunning video taken of the levee breach, including aerial footage shot with a drone.

 

 

 

 

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