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Vetting Sonoma Baylands
Peter Baye stood on the levee circling Sonoma Baylands on a bright day this fall and thought that despite the fuzz of cordgrass around its edges, the restoration project still looked more like a shallow lake than a marsh. Baye, a U.S. Fish & Wildlife biologist, is one of half a dozen wetland and wildlife experts trying to assess when - if ever - this political darling of the region's restoration projects will be a functioning wetland, flushed daily by the tides and teaming with cordgrass, pickleweed and clapper rails.
"It's not good enough to say 'well, we've got a lagoon, that's nice,'" says Baye. "I think we need to make good on what's been proposed."
What was proposed was restoring almost 300 acres of subsided hayfields near the Petaluma River to tidal marsh, with the help of 2.5 million cubic yards of dredged material. The use of dredged materials to provide an elevation lift, though controversial among enviros, was touted as a "win-win" solution to the nagging problem of what to do with the leftovers from a Port of Oakland channel deepening project . Project designers calculated that the lift would cut 30 years off the time it would take nature alone to restore the wetland to tidal levels.
Critics of the project have questioned more than just the use of dredged material, however. Phil LaRiviere, a retired physicist and environmental watchdog with the South Bay's Citizens Committee to Complete the Refuge, has had serious questions about the project since it began. "The projected timeline has been overly optimistic all along," he says. "September 2000 was supposed to be 'mudflat month,' and it's nowhere near that."
LaRiviere thinks one major hold up is the channel connecting the Bay to Sonoma Baylands (through an outboard marsh), which he doubts has ever been adequate to the job of eroding and importing sediment. "You can't feed a giant marsh through a mosquito ditch," he says.
Project designers chose not to dredge the channel in order to avoid disturbing endangered clapper rails and salt marsh harvest mice, according to Laurel Marcus, who worked on the project for the Coastal Conservancy. "Instead of bringing in all kinds of equipment, we wanted to wait and see if nature could have the same effect," she says.
While some feel the Baylands is behind schedule, hydrologist and lead designer Phil Williams, who is now monitoring the project's progress for the Army Corps, feels things are pretty much on track. The channel to the project's pilot unit (29 acres were breached first as a test site) has eroded to full tidal action, says Williams, and is "right where it should be after a four year lag. Had we not used dredged material, we'd be a lot further behind."
The main unit (breached 10 months later) is evolving more slowly. While its tidal channel continues to erode, it only has muted tidal action right now, according to Williams. He expects to make new projections about when full tidal action will be established with the help of additional monitoring data ready within the next few months.
Despite its lagoon-like appearance, Sonoma Baylands is already providing some habitat. Bird expert Jules Evens, who is monitoring avian use of the site, says he's seen an increase in species diversity since the project's inception. Although the greatest numbers of birds now using the site are waterfowl - rather than clapper rails or shorebirds - shorebird numbers (particularly avocets) are on the rise. "I think it's premature to assume that the intended results aren't occurring," says Evens. "The system is dynamic and changing rapidly. Tidal marsh is increasing in the main unit, and we're hopeful that rails will colonize the area in the future." Evens adds that one goal is for the whole area to support higher species diversity - of waterfowl, waders and shorebirds, rails, and tidal-marsh dependent species like song sparrows, as well as terns, gulls, even raptors. "As future monitoring clarifies the trends in wildlife usage, management [changes] might be needed," he says.
Other experts insist that the project needs to meet its primary goal - providing habitat for endangered tidal marsh species - sooner rather than later. "What's critically missing in San Pablo Bay right now is habitat for the rail and mouse that is free from predators," says Peter Baye. "Instead, it's pretty clear that Sonoma Baylands today is a shallow, microtidal lagoon, a giant flooded salt pan." While lagoons may provide habitat for certain birds, they do not offer the cordgrass and pickleweed needed by rails and mice. And the project may not be a safe haven. "Our fears that the levees,[the peninsula-type barriers designed to slow wave action],would act as corridors for predators are being confirmed," says Baye. "We've seen fox and coyote scat out there, although the coyotes will limit the foxes."
While most of the concerns over Baylands center around its immediate - or 20-year - success, other scientists have raised concerns about its fate over the long term. "The million dollar question," says the U.S. Geological Survey's Bruce Jaffe, who has studied sediment movements in San Pablo Bay over the last half century, "is whether deposition nearby indicates there will be enough sediment for successful restoration or whether the fact that San Pablo Bay as a whole is losing sediment indicates that restoration will be slowed or unsuccessful." Jaffe's guess is that the generally erosional state of San Pablo Bay could mean problems in the long run. But, he adds, "Engineering the project to decrease the demand on sediment supply - i.e. filling with dredged material - improves the chances of success."
In all fairness, restoration is a new science, and the best plans may not always pan out according to human schedules. "Sonoma Baylands is an innovative experiment, whose design underwent extensive review," says wetlands scientist Josh Collins of the S.F. Estuary Institute. "It applied a very sophisticated engineering approach, aimed at controlling the rate of sedimentation via levee breach height and channel size, to a dynamic and unpredictable environment. It's difficult to hold this kind of project to a timeframe that's nature-dependent."
But even Collins thinks nature may need a little boost. "If you look at this project's performance criteria, it's not doing what it said it was going to do. The responsible agencies are saying, 'well, not yet, but it will.' They need to make a measured policy decision about what's fast enough for them, about whether to leave it alone or do something."
That something, from Baye's perspective, should be to dredge the channel in the main unit to achieve full tidal range. Dredging would have to take place outside the rail's breeding season, and spoils would need to be carefully disposed of inside the lagoon rather than being cast off to the side, says Baye, to avoid creating berms that could act as outposts for invasive species or cause other problems.
The decision whether to dredge or not will be made by the Army Corps some time next year, according to Williams, in consultation with other agencies. But Williams urges caution. "The costs and tradeoffs involved in speeding things up should be weighed first. If we're going to spend a half million dollars, we need to make sure it's worth it."
Baye feels the project has languished long enough. "If we're serious about getting Sonoma Baylands on track, we need to start initiating the permit process now. My concern is that there are some private landowners out there looking for reasons to cast doubt on restoration projects. We need to get rid of the political polarization and just make it go." Contact: Peter Baye (707) 562-3003, Phil LaRiviere (650) 493-5540 or Phil Williams (415) 945-0600 LOV
Copyright © 2002, San Francisco Estuary Project