Special Section, July-September 2007

Napa-Sonoma Marshes:
From Salt-Making to Levee-Breaking

A 2004 aerial photo of Pond 2 (left), former Pond 2a (center), and Pond 3 (upper right) shows the difference between ponds inside intact levees (2 and 3) and those opened to tidal influence (2a). Note the emerging vegetation and sloughs in the latter. Pond 3's levees were breached in 2006 so it is now on its way to becoming tidal marsh like 2a. Photo by Larry Wyckoff, CA Dept. of Fish and Game.

by John Hart

We are somewhere west of the Napa River, nosing in a small boat along a slough between hollow islands known as Pond 2 and Pond 5, trying to grasp just how much has changed hereabouts in the last 24 months.

Just as you would have three years ago, you experience only a narrow, reed-fringed channel under a big, bright sky. The tide is high and the levee tops seem fragile and low. Now and then a power line, a leaning hunter's shack, or a glimpse of the Napa River Bridge reminds you of the urban world not far away. It takes a sharp eye and the knowledge of a guide like our pilot, Greg Green, to read signs of change. Here, for instance, a line of survey stakes extends into the water. The outermost stake once marked the edge of bordering tules that since have been torn away. Carrying more flow than it used to, this slough is widening. "That's what we're looking for," says Green. "This system has had restricted breathing for the last 100 years, and now the restoration project is opening it up."

After decades of being cut off from Napa Slough, Pond 5 was opened to tidal influence in mid-2006, when excavators opened several breaches in the surrounding levees. Photo by Mike McFadden, Cooper Crane and Rigging.

Coming around a corner, we see some of that current pouring through an opening, made just a few weeks ago, into the interior of the former Pond 5. In March 2006, the pond was drained of its brine. Then bulldozers and backhoes brought in on barges accentuated the courses of old interior sloughs that will resume their function as the arteries of a new marsh, plugged unwanted old ditches, and shaved the top off several levees so the highest tides will swamp them. The reduced dikes will support plants like marsh gumplant, providing high-tide refuges for salt marsh harvest mice and clapper rails; the occasional drowning will kill off unwanted weeds.

We stop on the opposite bank of China Slough and climb that dike to see another kind of restoration. Beyond is a still sheet of open water, just deep enough to support a fine stand of widgeon grass, favored feeding ground for ducks that dive for a living, like the canvasback. As much as 90 percent of the canvasback population in San Francisco Bay has been counted on Pond 2. Here the strategy is not to change the habitat but to protect it by strengthening eroded dikes.

A few miles down China Slough, an older opening into the space known as Pond 3 shows a later stage of marsh evolution. When we turn into the breach, canvasbacks, pintails, and whimbrel rise at our approach. There's a big crowd of godwits and other shorebirds on a shaved-off levee slope. Even on this high tide, patches of mud and vegetation are appearing. "This one is quickly progressing to a tidal marsh," says Green.

It's a satisfying end to what seemed like years of stasis.

Improvisation to Restoration

The State Department of Fish and Game (DFG) had long hoped to acquire the Cargill salt ponds as the key to restoring the Napa-Sonoma Marshes, the wetland expanse west of the Napa River. When the hope was realized in 1994, the new managers found they had a tiger by the tail. They had far too little money, far too little information, and too much of one thing: salt.

Salt ponds are, not surprisingly, salty. Up to a point, this is a fine thing for wildlife. But the final stops in the 12-pond Cargill system were pretty sterile places. Salinity buildup at the north end had created a weird scene of rust-orange waters, dead trees, and salt-encrusted embankments. The pond with the unlucky number 7 was a true toxic sump; it had been the dumping ground for bittern, the toxic solution that remains after sodium chloride has precipitated out of water.

Cargill was gone, but the salt-making machine it had built could not simply be shut down. Without a continual input of new water, the ponds would eventually dry up, losing all their value for birds. So the state managers continued to pump water north from the bay. Yet every added gallon brought with it its quantum of dissolved minerals, which were no longer being removed at the end of the line. If this process continued indefinitely, one pond after another would go the way of the poisoned northern ones.

The wholesale breaking of dikes was really not in the cards either. Next door to the ponds was the Napa River, itself an important fish habitat and protected waterway. Even the fresher ponds were mostly too briny for casual discharge. Nor was there yet any scientific basis for deciding which ponds should be restored to marsh and which should be retained as open water.

Needed, obviously, was a great deal of study, a careful plan, and a very large budget (eventually pegged at $100 million). While these ingredients were painfully coming together, the word of the day was "improvise."

Chief improviser was Tom Huffman, manager of DFG's Napa-Sonoma Marshes Wildlife Area. With his camouflage clothing, blond beard, and duckbill cap inadequate for the sun exposure he gets, he has the look of a fellow whose days are spent outdoors—many of them on these sloughs, where he was busy tending a terminally creaky apparatus. Dikes were leaking and eroding. Siphons linking the various ponds were prone to plugging, and pumps were underpowered. Huffman recalls once fixing a failing tidal gate with a piece of scrap metal picked up beside the highway. "When I look back on my career," he says, "one of the things I'll be most proud of is that I kept it going as well as I did, on as little as I did, for as long as I did."

Behind the scenes, though, help was on the way. State bond measures approved in 2000 and 2002 included funds for restoration of wetlands around San Francisco Bay. The Coastal Conservancy, armed with bond money and long expertise at shepherding complex deals, was building a partnership including the Army Corps of Engineers and DFG. Engineers were analyzing the ram-shackle system and what might be done with it. Scientists were at work defining which birds and fish benefited from the ponds as they were and as they might be.

By 2003, there was a plan. Four large ponds adjoining the Napa River would be opened to tidal influence and become marsh. Five ponds to the west would continue as open water for the benefit of shore-birds and ducks. (In some cases this required expensive repair of levees and water control structures.) That left the three saltiest northern ponds, including the lethal Pond 7. Here the planners adopted a solution offered by the Sonoma County Water Agency: Highly treated urban wastewater would be mixed with the bittern, shortening the timetable for dilution and discharge.

In 2005, Ducks Unlimited, Greg Green's outfit, was hired with funding from the state Wildlife Conservation Board to carry out the first phase of the plan. Once begun, the job proved easier and even a little cheaper than expected. In March 2006, at the end of a wet winter, the first "salinity reduction breaches" were made. The brine was easily absorbed by swollen sloughs, and in June the go-ahead came to make all 14 planned levee breaks. The fearsome salt monster seemed to have dissolved in the rain.

And wherever dikes have been breached, the once seemingly unstoppable force of salt buildup has given way to another formidable force: nature's tendency to build a tidal marsh if given room to build one.

What is happening in the former salt ponds is almost entirely out of the public view. The restoration of the Napa-Sonoma Marshes will really become a presence for people on the day when water reclaims the Cullinan Ranch along Highway 37. This sprawling tract, almost surrounded by the salt ponds but never one of them, has been a farm, the site of a planned city, and now a key asset of the San Pablo Bay National Wildlife Refuge. Plans due out this summer are expected to lead to its full restoration as marsh. The Ducks Unlimited team will be working here, too, probably in 2009.

Canvasback

On an early map of San Pablo Bay, made in 1775, the Spanish explorer Jose Canizares wrote this phrase: "forests of the red duck." The "forests" were the North Bay marshes, and the "red duck" was Aythya valisneria, the canvasback. The male has an off-white back, chestnut head, and—in breeding season—startling red eyes; the female is more subdued in brown and gray. Also distinctive in the species is the steeply sloping, blackish bill.

The canvasback is among the largest of the North American ducks, one of the fastest flying, and one of the deepest diving, able to go down as far as 50 feet underwater. Numbering about half a million, it is also the least numerous among widely distributed duck species, and wildlife conservationists keep a wary eye on its population.

Photo by Rick Lewis.

The canvasback breeds in the Arctic and the northern plains and spends the months between November and February in warmer climates. San Pablo Bay has long been one of its most important wintering grounds. It feeds here mostly on clams and other invertebrates, especially in underwater beds of eelgrass and widgeon grass. An alarming population sag in the 1960s was one of the factors that led to establishment of the San Pablo Bay National Wildlife Refuge in the shallows and adjoining marshes along Highway 37. No less important than the formal refuge were the adjoining Cargill salt ponds, where the vast majority of the region's wintering canvasbacks could sometimes be found.

For decades now the population of canvasbacks in the Bay Area has been declining. The birds have been progressively shifting to the San Joaquin Valley, perhaps because more good pond habitat has become available there. Their total numbers overall, however, appear to be holding their own.

Though the awesome throngs of canvasback once found along San Pablo Bay seem to be a thing of the past, many of these beautiful ducks can still be seen there. The best month is November, and perhaps the best place to see them remains Pond 2 (access by water) or the relatively deep northern edge of Pond 1.

The View from the Can Club

On a fall day in duck hunting season, the sound of shotgun fire echoes across the Napa-Sonoma Marshes. It will continue to do so. Here as elsewhere, hunters have paid a good share of the cost of habitat protection, and they are welcome in principle on most of the region's public wildlife lands. Ducks Unlimited, a conservation organization firmly rooted in the hunting world, is doing much of the on-the-ground engineering for marsh restorations. To the people out there with their boots in the mud, hunting and environmental conservation are old friends.

To many urban environmentalists, though, the alliance seems a little uncanny. Despite common interests, a cultural gap yawns wide between those whose enjoyment of nature is centered on hunting and those whom the sport leaves cold, or worse. All the more interesting, then, is the coalition that arose in defense of one of the region's oldest hunting institutions, the Can Club at Pond 2.

Photo by David Sanger.

When Leslie Salt bought and flooded the former Hantaberry Ranch in 1952, it inherited an already 60-year-old hunting establishment and created an ideal habitat for diving ducks. The club renamed itself the Can Duck Club, after the canvasbacks that thronged to the deepened pond, and signed on for a 50-year stay.

In 1994, with 47 of those years gone by, the landlord changed. The new owner, the Department of Fish and Game, wanted this private enclave out and the general public in. To buy a little more time, club president Lew Allen reached out to environmental organizations like Save the Bay, the Sierra Club, and Marin Audubon, inviting small groups to the rustic diketop clubhouse. The guests shared meals in the wide, high-ceilinged room with its decor of mounted birds and hunting art, heard some of the hunters' favorite stories, and got their view of the world: how the club restricted its numbers to avoid over-shooting, how it helped the cash-strapped state maintain dikes and watergates. On gray winter evenings around the big fire, real friendships arose. "In a way," says Allen, "those years were our high point. We made it a beautiful place to go."

Out of those evenings came a crosscultural lobbying group called Friends of the Can Club. Partly due its efforts, the club received two five-year lease extensions. As we go to press, a third has been denied. This was probably inevitable, Lew Allen concedes. Many more hunters and fishermen now will have access to the pond. But the end of the Can Club also signals the end of a pretty good conversation—the kind of exchange that's important for all concerned.

You will find this article and additional features in the July-September 2007 issue of Bay Nature, available through our online store or by calling (888)4-BAYNAT or
(888)422-9628. You may also purchase the current issue at bookstores and other retailers in the San Francisco Bay Area.

John Hart is the author of a dozen books on environmental issues in Northern California, including San Francisco Bay: Portrait of an Estuary (UC Press, 2003) with photos by David Sanger, and Legacy: Portraits of 50 Bay Area Environmental Elders (Sierra Club Books, 2006) with photos by Nancy Kittle. His articles have appeared frequently in Bay Nature.

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