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Salt Pond Shakedown
As state and federal dealmakers prepare to plunk 100 million greenbacks down on the Cargill table for close to 16,500 acres of saltscape, resource managers, enviros, and taxpayers are scrutinizing the steps that need to be taken to put the old salt production workhorses out to pickleweed pasture. Last fall, Cargill offered to sell 58 South Bay salt ponds and 1,400 acres of North Bay crystallizer ponds (in salt production mode since at least the 1930s) to the public to be restored as tidal wetlands. Most agree that the deal is an unprecedented opportunity-but not one without some interesting hurdles.
"This is without a doubt one of the best things that's happened to the Bay in a long, long time," says Marc Holmes with the Bay Institute. "A restoration of this magnitude presents enormous challenges, but I don't think they are insurmountable." The big concern, says Holmes, who is echoed by many others, is how to bankroll the cool billion - ten times the sale price - necessary to transform saltscape to tidescape.
"If this project is going to succeed, there has to be a commitment from both the state and federal governments to fund it at a reasonable level," says Holmes. "Even at a high estimate of $1 billion for restoration over 100 years, we're still not talking about very much money per year compared to what's been allocated to the Everglades. Someone needs to decide that the Bay is worth that kind of money." Holmes says that one big potential pot of funding-a $40 million restoration authority requested by the Army Corps-was axed recently by the Bush Administration.
Dollars aside, there are plenty of other burning issues. The steps that must be taken before the ponds can be returned to marsh, it turns out, are not simple, and there is no one-size-fits-all solution for all of the ponds.
"Every pond tells a unique story depending on salinity, elevation, water depth, and distance from Bay," says the S.F. Regional Water Quality Control Board's Steve Moore. The story line for most ponds: How concentrated are the brines; how long will it take for Bay water to dilute them; and how far below sea level have the ponds, long-separated from Bay sediment inputs by levees, sunk?
A starting place for the South Bay ponds, say resource experts and regulators, is to build on our experiences elsewhere. In the North Bay, at the imaginatively named "Pond 2A" for example, it took only a few sticks of dynamite to launch a thriving wetland while the South Bay's Cooley Landing required some clever ditch digging (see The Monitor). But other ponds, like Cargill's 10,000-acre North Bay foothold, acquired by the state in 1994, have presented resource managers with huge maintenance challenges.
"The most important lesson learned there is that we should have had an interim management plan," says Marge Kolar with U.S. Fish & Wildlife. The Regional Board, Cal Fish & Game, Fish & Wildlife, and others are now crafting such a plan for the South Bay ponds.
"The goal is to keep things in a steady state while planning takes place," explains Moore. "In order to move water, quit making salt, and not threaten water quality, the ponds have to be re-designed and some water structures put in to facilitate flows. We want more of an equality in water quality between the ponds and the Bay." Moore thinks achieving this equality, with all the funding uncertainties and lessons learned about maintaining the North Bay ponds on a shoestring budget, should be accomplished with the most passive system possible and mimic what "nature would select." He says, "We want to minimize costs by designing a system where we maximize gravity flow and minimize the number of water control structures."
But some artificial structures are likely, given what seems to be a general consensus that a certain number of salt ponds must be preserved in perpetuity. Scientists worry that turning too many into marsh will harm the western sandpipers, snowy plovers, diving ducks, and other birds that currently use the ponds.
"We've lost 80% of our tidal marsh, but we've also lost about 40% of our mudflats, too," says the Point Reyes Bird Observatory's Nils Warnock, who explains that some birds are using the food-rich ponds to compensate for the lost mudflats. But Warnock and Kolar both worry about long term upkeep. "Ponds are expensive to maintain and hard to manage," says Kolar. "Marshes are much easier."
Stuart Siegel, who has analyzed the South Bay ponds in detail (see Now in Print), concluded (as did the Habitat Goals report), that to provide diverse habitat for many species of birds, about one-third (4,700 acres) of the 13,700 acres of salt ponds should be maintained as managed, shallow open water, and two-thirds (9,000) acres) restored to tidal salt marsh. Deciding exactly what this habitat quilt should look like may be dictated to some degree by exactly which ponds are included in the acquisition. Those easiest to restore-Mowry 1,2, and 3-were not included. Closer to the Bay and less subsided, they could have been restored quickly at relatively low cost. In contrast, some of the ponds that are part of the deal are deeply subsided and located farther from the Bay. As one way to speed restoration of the Alviso ponds, Siegel says, dredged sediments could be used to rebuild elevations and compensate for the South Bay's wetland-building sediment shortage.
But some environmental groups worry that raising the specter of dredge spoils at this point is a red herring that could deter restoration. Says Save the Bay's David Lewis, "The issue is not whether we support or oppose the use of dredged material. The question is whether to raise that large scale issue right now." That said, Lewis is concerned about the cost of getting dredged materials to the subsided areas and about where the material would come from. "The only project that could produce that much material is the airport."
Siegel argues that sediment and subsidence need to be looked at now. "We know we have a sediment deficit. We know we want to spread restored tidal marshes geographically around the South Bay. We know the major subsidence is from Mountain View to San Jose. Consequently, solutions for the subsided Alviso ponds need to be found." If the sediment deficit is not resolved and ponds are opened to the tides too quickly, says Siegel, valuable South Bay mudflats could be scoured: the sediment has to come from somewhere. And using material from routine dredging projects alone (i.e., without SFO dredging) could shave the time it will take to restore the acquired ponds by as much as 50-60 years. "You have three options," says Siegel. "Use dredged material in some Alviso ponds, do long-term phased natural sedimentation (open up the ponds slowly over decades), or have some kind of muted tidal regime with complex water control structures. That's the trickiest because it's the least certain ecologically and requires more management and maintenance."
Once the interim operating phase begins, resource managers can begin talking about long-term management and the nuts and bolts of actual restoration. The Coastal Conservancy will lead the restoration planning effort and is beginning to organize all of the players and the endless list of issues, which include a more detailed look at flood management, public access, and invasives control (among many others). Long-term planning and fundraising will occur during the interim phase, says the Conservancy's Amy Hutzel, which could take up to five years and cost up to $10 million.
One thing that is becoming crystal clear as the salt begins to evaporate is that opinions about exactly what can and should be done in the South Bay are as diverse as the birds using the ponds.
"If we proceed towards 'instant gratification' of salt pond restoration to tidal marsh, we will be irreversibly committing all future tidal marsh in the Bay to Atlantic-type salt marsh composition and structure," says wetland expert Peter Baye. "It's happening now at a small scale-all East Bay tidal marsh mitigation sites are overrun with the hybrid Spartina alterniflora - and it's a poison pill for those who worked for decades to restore salt ponds to tidal marsh."
In the meantime, plans for the "mothball" phase roll along. "Even in the interim, we can improve habitat values without disturbing species like the snowy plovers -why would we mess with that?" says Moore. "I think we'll see some strides toward restoration. There'll be some neat stories along the way. We won't just be freshening ponds."
Contact: Marc Holmes (916)648-1161; Steve Moore (510)622-2439; Stuart Siegel (415)457-6746; Amy Hutzel (510)286-4180 LOV
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