America is losing wetlands at an accelerating rate. The average annual rate of loss between 2004 and 2009 increased by 25% over the five-year period ending in 2004, a US Geological Survey study recently reported.
The USGS study included coastal wetlands on the Atlantic, Gulf, and Pacific coasts. All have been subject to wetland loss, although at varying rates and for differing reasons. The USGS found that Atlantic coast wetlands had net losses of 111,960 acres, the Gulf of Mexico coast lost 257,150 acres of wetlands, and Pacific coastal regions lost 5,220 acres. The watersheds of the Great Lakes region, however, experienced a net gain in wetland area of an estimated 13,610 acres.
Although the study does not discuss the quality or ecological functionality of the remaining wetlands, it does express particular concern for “the continued loss of vegetated wetlands to human-related causes. In some regards, our understanding of coastal processes and interactions has not kept pace with the cumulative impacts resulting from wetland loss due to human-induced actions.” Therefore, it probably goes without saying that quality matters at least as much as extent. And human activity has undoubtedly continued its intense pressure on the quality of wetland resources as development, industry, commerce, and recreation continue to favor coastal regions, not just in the United States, but around the world.
Paula Golightly, supervisor of the habitat restoration staff in the Arcata Fish and Wildlife Office in Northern California, said some of the most productive wetlands, such as estuarine systems housing the transitional interfaces from salt to brackish to fresh water, are under particular threat. “That interface has been lost in a lot of places,” she says.
While the rush to develop coastal areas for recreation, residential, and commercial purposes, along with sea level rise, might be the most well-known of current threats to coastal wetlands, there are whole swaths of wetlands that went missing generations ago, converted to farmlands to feed a ravenously growing young America. At the time, wetlands were simply called swamps and were considered unproductive wastelands and breeding grounds for miasma. It was long considered a service to the community or even to the nation to fill in a wetland.
However, two projects demonstrate that there is a lot to be gained by undoing some of these achievements.
De-Pasturizing
Giacomini Ranch was a dairy farm at the headwaters of Tomales Bay on the north coast of California. Cutting into the wetlands and high marshes feeding into the bay, Waldo Giacomini built levees and pumped the water out decades ago. The land added capacity to his dairy during the 1940s to supply more milk and help America get through World War II.
After the war, the Giacomini family pressed onward with their 550 acres of low-lying pastures and other holdings for at least couple of generations, steering their way to becoming one of the most productive dairy operations in Marin County. Doug Hanford, president of Hanford ARC, a California firm specializing in environmental restoration, says the ranch Waldo Giacomini built on Tomales Bay marshland, at least to the untrained eye, “would not have looked much different from many of the other dairy farms in the region. It was not at all evident that it was wetlands, just to see it.”
Hanford recalls that there were still a few cows roaming the meadows in 2000, when he first visited the farm at the completion of a 10-year-long site acquisition process, which, through a purchase agreement, transferred ownership to the National Park Service (NPS). Once the last phases of the dairy operations wound down, however, and a separate contractor had dismantled and removed the barns, manure storage, irrigation systems, and other farm infrastructure, the task of opening the gates to nature fell to Hanford.
This is just the kind of project for which Hanford says his company is well suited. “We do lots of wetland work, including freshwater wetlands, saltwater wetlands, and tidal wetlands,” he notes.
Hanford says what makes his firm so adept at wetland work is its in-house capability to handle nearly every phase of post-design construction engineering on restoration projects, “from earthwork to seeding and planting, right down to maintenance.”
He sees wetland restoration as a growing field of operations for his company. “When the company started 29 years ago, there was very little wetlands work, but over the past 20 years the jobs are becoming more frequent and bigger.”
Hanford, however, views wetland restoration as part of something bigger than just a good business proposition. “The value of wetlands and the role they play in the environment is becoming more evident and known,” he says. “They protect us from storm surges, they help clean our water-they’re incredibly complex. They provide habitat for fish, birds, and wildlife of many species.” Although he perceives an increasing willingness to fund wetland restoration, he says, “Money is still tight.” However, on the positive side, he adds, “We’re finding there is much more awareness about [wetlands] and much more pressure from the public and the agencies to create and preserve them.”
At the same time, he says the projects themselves are becoming more complex. “The science behind it, the knowledge, the agency requirements-everything is getting more sophisticated as the knowledge base grows. There is a lot of science that goes into these projects and into these designs.”
Hanford brought in a hydrological team from Kamman Hydrology and Engineering Inc. to evaluate the Giacomini Ranch’s potential for carrying water.
“It’s a historic wetland, so we went back in and located all the historic channels and excavated them, got it all re-excavated and shaped so that when the water was reintroduced later it would function and flow in and out as it had historically,” he explains.
The 550-acre site, much of it below high-tide elevation, had for more than half a century been cut off from Tomales Bay by more than 10,000 linear feet of levees, with a series of tide gates and a network of constructed drainage ditches to keep the grassland dry enough for grazing. The planned restoration would backfill the drainage ditches, reassemble the watercourses to mimic their original configuration as a web of tidal channels, and ultimately take down the tide gates and breach the levees, allowing bay waters to once again ebb and flow naturally over the lowlands.
Don’t Pump It Up
Although the plan sounded relatively straightforward, Mark Cederborg, project manager who oversaw construction for the company, says, “Wetlands have some unique challenges. We were recreating a tidal wetland in a tidal zone, so the soil substrate can vary diurnally.” According to Cederborg, in the lowest areas the ground was between 1 and 2 feet in elevation. “There were different times of the day the soil would saturate from underneath as the tide rose on the other side of the levee,” making it impossible to accomplish much work with the heavy earthmoving gear required for reshaping the landscape. “There is a lot of pressure from the water building up on the far side of the levee,” he says. “It was not real evident. It’s not like the field flooded every day, but when you’re driving large equipment on something like that, a small change can affect the ability of the ground to support the equipment.”
He adds, “In some areas of the project the logistics were very challenging, and we were required to use an assortment of low-ground-pressure equipment, such as low-ground-pressure tracked excavators and tracked trucks, tracked bulldozers, and those kinds of things.”
Variable conditions meant it was important to have a variety of options to compensate and keep production going, he says. Efficiency on the job required having on hand multiple pieces of gear that performed essentially the same function that could be switched out depending, literally, on the weather and the tides.
“There are not many manufacturers of tracked trucks,” he notes. “We’ve used Morooka and Yanmar. It’s a little bit of a niche market.” He says the choice often depends on what’s available for rent in a given area.
Some sneaky little problems can crop up when working on a wetland site. Although there may be a dry layer of soil a couple of feet deep at the surface, there is often heavy moisture just below that. In such situations, Cederborg says, it’s important to be on the watch for a phenomenon called pumping, which occurs when a heavy truck follows the same track repeatedly, pulling moisture to the surface by pressurizing and releasing the soil below with each pass, “which reduces the ability of the soil to support the truck.”
One solution to this problem is to vary the haul routes, but Cederborg says the wetlands housed a number of sensitive habitats, and NPS made it clear “they didn’t want traffic traveling all over the site. There were designated haul routes, so that also concentrates your traffic, increasing the likelihood of pumping.” The other solution is to periodically change trucks. “There might be vehicles that you could use over time, but then you’d lose the ability to support that equipment, and then you’d have to switch.”
Cederborg says that when it came to logistics, “there was generally a collaborative decision-making process” among the project principals, including NPS, the contractors, and other partners. Cederborg says, however, that after a while intuition also began to play a role. “You knew in what areas you could or couldn’t do things and what type of equipment you’d have to use to get that work done.”
Niches in the Breach
“We were changing it from one type of jurisdictional wetland to another,” Cederborg says. That meant the wetland species onsite, particularly those with federally endangered status, would be due some accommodation.
Paradoxically, Cederborg says, transitioning from grasslands back to the more natural marshland situation would not necessarily be a welcome change for all the species in residence. In fact, two species-the California red-legged frog and the tidewater goby-had been found to inhabit ecological niches that were slated to be eliminated. The goby was found in living in the drainage ditches carved out generations earlier by the dairy farmers. And the frog inhabited lowland ponds in areas destined to be inundated by saltwater when the levees holding back the bay were finally breached. But even that had been taken into account in the project plan.
To accommodate the frogs, the restoration created two new freshwater ponds totaling 0.73 acre upland of the saltwater marsh. These, along with a newly constructed freshwater marsh of 5.2 acres, would allow them to continue their sojourn in the region relatively unperturbed by post-breach salt concentrations, which research had reported could upset their reproductive cycles.
Similar measures were taken to protect habitat for the federally endangered tidewater goby, a small brackish-water-resident estuarine fish. The goby, NPS noted in its project summary, “tends to thrive in muted tidal zones or impounded conditions and off-channel habitats rather than in areas open to the full flood and ebb of the tide.”
Among other measures benefiting the goby, several features of the old farm were specifically maintained at the site to provide muted tidal habitat, including the East Pasture Old Slough Pond. In addition, a feature known as the former Tomasini Creek channel, where goby were first documented, was maintained as a backwater slough feature.
Cederborg says that overall, once construction began, the site bore no real surprises, “a testament to careful the planning and excellent hydrological analysis beforehand.”
Grade-A Wetland
In addition to removing levees, filling drainage ditches, and creating new tidal channels, other highlights of the project included realignment of leveed creeks, removal of tide gates and culverts, enhancement of creek banks along Lagunitas Creek through riprap removal and creation of floodplain terraces and benches, and lowering of adjacent creek bank elevations. The project also restored the Dairy Mesa area to more natural contours similar to those of the adjacent Point Reyes Mesa. And finally, the project achieved the initial restoration of Olema Marsh by lowering a section of berm and excavating to improve hydraulic connectivity of the marsh interior with a main creek channel known as Bear Creek.
Although he notes it’s essential to have top-notch hydrology to back up a wetland restoration, Cederborg says, “The other thing that’s cool about restoring wetlands is that it’s not as precise a science as some other types of environmental restoration work, such as urban stream restorations,” which are often highly constrained by preexisting infrastructure. On a wetland project, once the process of breaching a levee is set in motion, the natural processes take over.
“Removing the levees has actually benefited a lot of people who were previously at risk of flooding after heavy rains,” he says. Relieving the pressure against the walls of the channels and freeing the floodwater from the artificial constraints imposed by the levees means that the water can now disperse over the wide expanse of terrain of the marsh plains, rather than backing up into residential areas.
With the breaching accomplished in 2008, Hanford ARC’s marsh restoration contract came to conclusion. The Giacomini Wetland has been integrated into the National Parks System’s Point Reyes National Seashore in California. Recently, NPS released a report covering five years of post-construction monitoring, indicating that wildlife has indeed returned to the site at a feverish rate. And the Giacomini project is now rated as one of the most resilient on the West Coast.
Cederborg, too, has returned the site on a separate Hanford ARC contract to set up trails to make the park more accessible to for the park’s other new visitors: tourists, who migrate in droves to the newly restored expanse of rare habitat just 30 miles from San Francisco.
He says it’s a real pleasure now to come out to the site, which he does from time to time not in a professional capacity, but like most of the other 2.5 million visitors to Point Reyes National Seashore, just for fun. He says it’s illuminating to watch the renewal process unfold on the former rangeland. “For me it’s about the change. The average visitor would never know it was ever a dairy; it’s growing the marsh vegetation.”
“I don’t think it was ever very high-quality dairy land. It was always pretty wet,” Doug Hanford says. But sharing Cederborg’s fascination as the marshes spring back to life, he adds, “We haven’t done a lot of planting; a lot of these projects, when you return them to what they were doing before, restore themselves quite rapidly. You’re just putting it back to the way nature wants it-the function returns quickly. Tides going in and out bring in the species. The maturity is not there yet, but the complexity is growing year by year.”
Old McDaniel Was a Farm
Coastal wetland restorations might not be a good business idea if you’re in a hurry to get results. Like the Giacomini project, the city of Arcata’s McDaniel Slough wetland restoration project, which just completed levee breach last September, had been a long time in coming. Mark Andre, project manager for the city, says it took about 10 years simply to acquire the target property, and that was with “a willing seller.”
Adding in the environmental design, the search for funding, and construction, implementing the project in total engulfed close to 15 years.
Intended to reestablish 280 acres of wetland habitat on farmland at the fringes of the city of Arcata, CA, the McDaniel Slough project would restore ecological function to lands that had been “reclaimed” from swamp by the construction of levees, pumps, and drainage channels as far back as the 1880s, a time when California was seen as a land of dreams.
Andre says the McDaniel Slough restoration didn’t really start out as a big dream, but rather had its inception in a small, but good, idea he had for improving water quality on Jane’s Creek, a stream that ran through town. Andre explains what he was thinking when he first approached the land owners: “We have a pretty active urban streams program, and the original motivation was to see if we could create a cattle exclusion area as a buffer along the creek.” But he said the Hunt family, owners of the farm, upped the ante and “suggested we just buy the entire ranch; that allowed us to think bigger, not just of restoring a sliver of riparian habitat for fish, but more importantly restoring an estuary that had been cut off from access to Humboldt Bay for over 100 years. Any chance you can restore an estuary-you’ve got to look at that.”
Shedding a bit more light on what the city began to envision, Andre explains, “Ecotourism is a significant part of our economic development strategy; we already have a wildlife area that has lots of visitors for bird watching and passive uses such as trails.” A restored, ecologically functioning wetland, bringing nature back to life in place of the farm at McDaniel Slough, would “greatly enhance that opportunity.”
Marshland Homecoming
Andre says the plan was literally to let the farm go under-underwater, that is. The city would dismantle the levees, remove the tide gate water control structures designed to keep the tides from rushing into the low-lying fields, and instead invite the tides to inundate and saturate the former pastures.
After acquiring the properties, lining up the funding with the help of the US Fish and Wildlife Service, and performing the appropriate hydrological and engineering studies, one of the first orders of business, ironically, was to build not fewer but more levees, this time to protect properties landward of the wetland project site. But Andre says these new setback levees, which he termed “eco levees,” based on a concept pioneered by the influential San Francisco engineering firm Phillip Williams Associates ESA, would be something different from the ordinary.
Employing a 10-to-1 gradient on the bayward side, the eco levees’ structure would “mimic the gradual slope of the run-up zone of a natural salt marsh colonized by vegetation.” The gentle slope would allow sediments to accumulate along the gradient as the tide moved in and out, and “by growing biomass out there on the urban fringe,” Andre says, the levee system could become stronger as time passed. “It’s a big part of our climate adaptation strategy,” he notes. The levees were designed not only to hold out water, but also to integrate habitat into their structure, with the vegetation serving as an anchor and as a mechanism for dissipating wave energy.
Philip Williams, founder and former president of Philip Williams Associates ESA, explains further: “We’ve really begun to appreciate the transitional habitats-those in the zone between the intertidal, which are regularly inundated by tides, and the upland habitats. It’s these areas, which might be inundated occasionally by storm-surge-event extreme tides or wave action, that are among the most productive. A lot of the ecological processes that are valuable occur in that zone. The idea was to try to expand that transition zone, within the design of a levee transitioning to a natural wetland. Instead of just having a flat wetland against a steep embankment or even a riprap embankment, you’ll start to see much more attention focusing on designing these transitional habitats.”
Additionally, Williams says, distributing a levee over a wider footprint can help counter the tendency of highly plastic mud earthworks to deform under the load imposed by the force of rising water behind them. However, he says that the degree to which the plasticity of the mud would be a concern depends on the soil characteristics of any particular project site.
Got Time?
The work did not proceed swiftly. The challenge of moving more than 100,000 cubic yards of material to demolish the old levees while building new levees further back, and carving out channels and borrow pits to supply material for these levees, proved epic, requiring the better part of five years to complete. According to Andre, part of the challenge involved the logistics of working with heavy equipment so close to sea level. Construction would have to wait until the water had “dropped to a certain point before the machines could even work,” he says.
In addition, he notes, the soil moisture content had to be just right to get proper compaction on the soil for building the new levees. “We get plenty of rainfall here, so the construction season is very short.”
Between the vagaries of the weather and the regularities of the tides, the entire project had to be squeezed into the brief moments when site conditions would allow work to proceed efficiently, which Andre estimates amounted to just two to three months each year.
“I’m not complaining,” he says. The five-year construction cycle, he notes, made the outcome of the entire project better. “We were able to amend the project to add about 60 acres in the middle on newly acquired land, which was really a nice feature.” The long timeframe also facilitated some thinking about additional interesting habitat types that could be worked into the project.
For instance, during the construction interim, the city of Arcata was able to get its wastewater plant’s discharge permit changed to allow the outflow from that plant to go into McDaniel Slough rather than directly into Humboldt Bay. The possibility of feeding treated water from the wastewater facility “into the mix of marshlands,” Andre says, “created an opportunity for a brackish marsh habitat component in the matrix of the larger salt marsh, and freshwater ponds.” This allowed the city to “get more ecological bang for the buck for the treated wastewater before it goes into Humboldt Bay.”
He says, “That’s a big feature that wasn’t even thought about early on.”
Marveling at the serendipity, Andre adds, “It just looked like a perfect match” to meet a designated goal of “creating a variety of habitat types.”
Rowing Together
Paula Golightly oversees the Partners for Fish and Wildlife Program and the Coastal Program on the north coast of California with a team of four scientists and specialists from the US Fish and Wildlife Service. The agency was one of many partners in the project, providing technical assistance, including consulting on regulatory compliance; providing assistance with hydraulic monitoring, design, and planning; and overseeing construction. In fact, Golightly says, the partnerships formed were some of the most outstanding features of the McDaniel Slough project.
According to city of Arcata environmental programs manager Julie Neander, in addition to federal support and the involvement from the California Department of Fish and Wildlife, “the McDaniel Slough project’s success depended upon area nonprofits, private landowners, and citizen volunteers.” Golightly adds, “Without that community support it would not have been possible to pull off a project like this.”
Doug Hanford says it’s helpful if contractors, too, can see themselves as part of the partnership during wetland restoration work. “Unlike conventional construction, where developers move from one building and on to the next,” he says that when it comes to wetlands restorations, “often your client is highly invested in the project-they are invested in the success of the project. Often the people you’re working for, like refuge managers, are located at the site; they have a great concern for what’s happening. You have to understand that when you’re working with them. And sometimes they are not that experienced in construction. You need a certain amount of sensitivity and understanding and foresight to be able to explain to them what’s going to happen to avoid issues down the road.”
Cederborg agrees, but adds that the commitment to the Giacomini project became a two-way street. “We worked out there since 2000. We were really vested the project; I gave talks to tour groups, going to meetings to educate the public about the project.”
Portrayed in photographs made by a local pilot who has been flying over McDaniel Slough making images is a transformation Golightly finds nothing short of astonishing. Although she says the recovering wetland seems to be unfolding almost precisely as planned, “It’s one thing to anticipate what it’s going to look like, but during some of the high tides, it’s really powerful to see how much of the area is inundated with water.
“The project partners put a lot of enhanced topography out there so there would be diversity of low areas and raised areas for roosting sites for shorebirds and things like that. So it’s been really neat to see those areas look like they’re functioning,” she says.
For Golightly, the project is much bigger than just adding wetland acreage to a farming district. “When you restore the mouth of an estuary” she notes, “you are restoring the food web; restoring the mouth is restoring the function of the watershed. It’s really important as a migratory corridor for things like salmonids, but there are a lot of other species as well that would want to be able to move up and down the system.”
A couple of months after the breach at McDaniel Slough, Paula Golightly says she loves to go out to the site, which for her is just a 10-minute drive, every chance she gets just to watch what develops. She is not the only one mesmerized by the transformation taking place. She feels the city of Arcata planned it that way. “They were immersed in the idea that you could appeal to a lot of different kinds of people with a project like this. When I drive out, there are always people walking around looking, just really curious-looking at birds, looking at things, very intrigued by it all.” And sharing in the spirit of wonder, Golightly says, “We still have a lot to learn from this as far as what actually happens through time.”
