South Bay Wetland’s Restoration Project9/8/2009
By ERICA GIES
HOST: The South Bay Wetlands Restoration Project is turning 26 square miles of salt ponds, formerly owned by agribusiness giant Cargill, into a variety of wetland habitats. The project is the second largest in the country – only the Everglades is larger – and will ultimately cost $1 billion.
For centuries, people thought of wetlands as wastelands. It turns out they are much more. They provide habitat for endangered species, nurseries for fish we eat, water cleaning and storage, carbon capture – and a vital buffer against storms and sea level rise. Reporter Erica Gies has the story.
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ERICA GIES: For decades, passengers flying into San Jose International Airport were treated to the strange sight of ponds below, a patchwork of Easter egg colors. The ponds were built to make salt, and algae created the colors. Now that landscape is changing as project managers are beginning to open levees and flush water through the ponds to let nature recreate the tidal marsh that once existed here.
[SOUND OF BACKHOE]
ERICA GIES: This is multi-decade project, and managers have to consider a lot of variables – not the least of which is a projected sea level rise of 55 inches by 2100. They know nature can ravage areas where wetlands have been destroyed, something shown by both the 2004 tsunami in Southeast Asia and 2005’s Hurricane Katrina.
Steve Ritchie is manager of the South Bay Wetlands Restoration project.
STEVE RITCHIE: Those tidal marshes are areas that, in effect, act as floodplains, both from tidal flooding and from drainage flooding out from the system. So those areas act as buffers and sponges that will absorb floodwaters.
ERICA GIES: As on the Gulf Coast, Bay Area wetlands are largely gone: just 15 percent remain of what was once a vast ring of marshes and mudflats, miles wide in some places. They were lost not just to salt production but also to the town of Alviso, to Moffett Field, to San Francisco International Airport, and to the world headquarters of many Silicon Valley companies such as Google and Yahoo, all of which lie below or near sea level.
Although it might seem a waste of money to recreate habitat that will soon be underwater, wetlands can, in fact, adapt to sea level rise.
HEATHER COOLEY: By trapping sediment and then growing upward, they can rise faster than sea level rise. They can also migrate inland.
ERICA GIES: Heather Cooley is senior research associate at the Pacific Institute. The independent research organization published a paper earlier this year on predicted sea level rise in California.
HEATHER COOLEY: If, for example, the wetland was surrounded by a paved area or a residential area, then chances are that it wouldn’t be able to migrate and adapt to rising seas. But if there were open space, or a park, or some other kind of less developed area, then that would allow the wetland to potentially move and migrate.
ERICA GIES: The restoration team may suggest restricting development. Meanwhile they are buffering existing settlement by restoring the wetlands and by protecting them as a part of a national wildlife refuge. But the marsh can’t form overnight. To grow, it needs both time and sediment. Laura Valoppi of the U.S. Geographic Survey is the lead scientist on the project. She is studying sediment availability.
LAURA VALOPPI: At least in the early stages, getting a handle on the sediment dynamics and the sediment budget is very important because, without the sediment, then there’s no foundation for the rest of the marsh to develop.
ERICA GIES: Sediment in San Francisco Bay is pushed around by tides. When it eventually settles around the edge, it provides soil in which marsh plants can take root. Sediment flow has been disrupted by development, landfills, and levees around the bay, but managers believe there’s still enough to anchor marsh growth in the South Bay. Project manager Steve Ritchie says if they knock down the levees that created the salt ponds, nature will restore itself.
STEVE RITCHIE: “You just poke a hole in the levee, and there it goes.”
ERICA GIES: If the system needs more sediment, managers might consider decommissioning outdated dams or moving muck from a stockpile near Alcatraz.
[SOUND OF BIRDS, TRAIN]
ERICA GIES: However, the area can’t be returned entirely to its natural state because both people and animals have moved in and adapted to the human-built environment.
CHERYL STRONG: The shorebirds and waterfowl that use the Pacific Flyway as their migration route have lost a lot of habitat in the Central Valley, for example, due to development and, even more so, due to agriculture. Those birds have shifted over to using the San Francisco Bay Area and the salt ponds for their migration pathway.
Cheryl Strong is a biologist with the U.S. Fish and Wildlife Service.
ERICA GIES: To protect these species, about half of the existing ponds will remain, although they will be managed as habitat, with water flow and islands for nesting. Managers may ultimately convert some of them to tidal marsh if they see the migratory species adapting.
LETITIA GRENIER: For most of these species, the answer is, if you build it, they will come.
ERICA GIES: That’s Letitia Grenier, head of the conservation ecology program at the San Francisco Estuary Institute, an adviser on the project.
She says animals won’t be the only creatures attracted to the new land. People will likely come too.
LETITIA GRENIER: If we restore those wetlands in the middle of the bay, we’re going to have this wonderful, wild place again right in the middle of all our urbanization, and it’s going to be a fantastic place where people can go and see wildlife, wildlife can flourish, and we’ll have all of those other benefits of wetlands.
Erica 09: Project manager Steve Ritchie says they are learning as they go, tweaking elements in response to nature’s reaction.
STEVE RITCHIE: If the fish and wildlife that are benefiting out there actually prefer some different arrangement of the habitat other than what our brilliant minds have come up with, because we read really good textbooks.… Well, they read different textbooks, and they’re going to do what they want to do, and we have to adapt to that.
The South Bay Wetlands restoration project will be ongoing for the next half-century. But for wildlife and people, its expanding mudflats, marsh grasses are already starting to provide.
In Newark, I’m Erica Gies, for Crosscurrents.