|Environmental Review Toolkit|
|NEPA and Project
|Section 4(f)||Water, Wetlands,
|Water, Wetlands, and Wildlife|
Wetlands and Aquatic Resources
inside cover quote -- "When we try to pick out anything by itself, we find it attached to everything else in the universe."
WETLANDS AND HIGHWAYS: A Natural Approach
What do a fresh-water marsh, a prairie pothole, and a swampy forest have in common? They're all wetlands.
Wetlands can reduce flooding, control erosion, and improve water quality. They provide habitat for about one-third of all federally-listed endangered plant and animal species, and nesting spots for more than half of the nation's migratory birds. They offer recreation, beauty, and visual "space."
They're valuable. And they're vanishing.
Scientists estimate that colonial America had 221 million acres (895,000 hectares) of wetlands. Since that time, 22 States have lost at least half of their original wetlands. Three of these states--California, Iowa, and Ohio--have lost approximately 90% of their original wetlands.
The losses continue. Some states may lose more than 20,000 acres (8100 hectares) of wetland this year.
The vast majority of these losses result not from highway construction but from agricultural conversion, natural erosion, and urban development. Still, every sector of society, including highway departments, must do its share to reduce further losses.
What can be done?
FIGURE 1 -- States that lost more than 50 percent
of their wetlands between the 1780's and mid-1980's
(Listed States shaded)
Minimizing wetland loss and therefore maximizing wetland values and functions is the ideal solution. That means responsible land use for those who build, manage, and drive on highways. It means taking steps to avoid the need for new highways--highways that may have to cross a wetland. It means ridesharing, telecommuting, or simply driving less.
"We must work together to save wetlands, and at the same time explore transportation alternatives that reduce the need for more roads," says Federico Pena, Secretary of the Department of Transportation.
To help reduce the need for more roads, there are now more tools and incentives available, thanks to the passage of recent legislation. The 1991 Intermodal Surface Transportation Efficiency Act, or ISTEA, offers more funding for alternatives like transit, carpooling, and bike lanes, and it strengthens requirements for planning and for citizen participation. ISTEA also encourages management strategies such as congestion pricing, "smart highways," and congestion management systems.
Figure- Existing Wetland Mitigation Banks
map, WETLANDS MITIGATION BANKING CONCEPTS,
U.S. Army Corps of Engineers,
July 1992, page 11
Sometimes a community or state decides it needs to reroute or enlarge a highway or build a new one. Once highway departments have clearly established the need for a highway in a wetlands area (and after they've explored all other alternatives), they must develop plans to mitigate or "offset" any wetland losses.
Wetlands mitigation projects are usually described in terms of "avoidance," "preservation," "enhancement," "restoration," or "creation." In-kind mitigation refers to replacement of a specific wetland type with the same wetland type. For example, a lost marsh would be replaced by another marsh--not a hay meadow or an alder swamp.
Figure-Wetland Mitigation Banks Under Planning
map, WETLANDS MITIGATION BANKING CONCEPTS,
U.S. Army Corps of Engineers,
July 1992, page 11
Highway departments sometimes use mitigation banking to protect wetlands. Mitigation banking is a system for balancing wetland losses against wetland gains. In this process, wetlands are restored, improved, or created by cooperative efforts, usually with pooled funds. (Under ISTEA, wetland banking projects are eligible for federal funding support). The "bank" holding the funds has an account manager--often an inter-agency committee--who determines wetland "credits" based on the quality or capacity of the newly-created or restored wetlands.
Determining the quality and capacity of a banked wetland is more than a subjective process. Typically, it involves an acre-for-acre exchange or another area-based ratio. Or it uses a scientific method to determine credits based on the human-use value or the physical or biological function of the banked wetland. For example, the habitat for a particular waterfowl species may be assigned a certain number of credits.
The "credits" in a mitigation bank are like cash deposits in a regular checking account. Once the account manager has determined the wetland "credits," he or she subtracts the "debits"--the unavoidable wetland impacts--and leaves the remaining "balance" in the account.
Usually, debiting is only allowed
Some wetlands managers and scientists prefer mitigation banking to project-by-project mitigation. Here are a few of their reasons:
TIPS FOR POTENTIAL MITIGATION BANKERS
To get the best results from mitigation banking:
SUCCESS STORIES IN MITIGATION AND MITIGATION BANKING
Many states have successfully used mitigation banking to save or improve wetlands. Other states have used different methods of mitigation to protect wetlands. Here are details about nine mitigation projects which have received acclaim for their success, conscientiousness, and innovation:
west of Hazel, Arkansas
Preventing incompatible development along a bayou. Creating additional space for floodwater storage. Designing safer havens for wetland wildlife.
The mitigation plan for Pine Bluff, Arkansas's US-65 Bypass -- the region's only southern east-west arterial -- will accomplish each of these goals.
The bypass will be 11.6 miles (18.7 kilometers) long and will roughly parallel Bayou Bartholomew (the longest bayou in the United States). Although approximately 26 acres (10.8 hectares) at four locations will be filled during construction of the bypass, about 200 acres (83.3 hectares) will be created and restored later, and an additional 200 acres of much higher quality wetlands will be purchased and preserved. These human-made replacement wetlands will restore natural water flow, prevent flooding, and enhance adjacent wetlands.The project's mitigation plan also features these innovative measures:
These innovative measures and others will save taxpayers more than 12 million dollars.
Throughout the planning and approval process, the Arkansas Highway and Transportation Department (AHTD) kept in constant touch with the public. "We participated in town meetings, and we invited local environmental groups to go on field trips with us," says Bill Richardson, assistant chief of the Environmental Analysis Division at AHTD. "We also held a joint public hearing with the Corps of Engineers."
Pine Bluff's planners are optimistic about the project's success, yet they're also realistic. "We've got to do something different and see if it'll work," says Bill Kirschner, EPA life scientist (and Corps of Engineers environmental specialist at the time of the project's conception). "We can replicate the look of a wetland, but only time will tell how well it functions."
Clio Wetland Replacement Project
On Highway 89 in Plumas County, along the Middle Fork of the Feather River, engineers filled an acre (0.4 hectares) of meadow adjacent to the river as part of a project to improve highway safety. To compensate for the loss, they created 1.9 acres (.77 hectares) of in-kind "wet meadow habitat" next to the filled area.
The project challenged all those involved, because scant published data existed about similar state projects in non-wooded areas near a river.
Careful planning and attention to detail were key to the project's success. Contractors were required to
More than 10,000 sod plugs were planted, each containing at least one shoot of Nebraska sedge (a plant species characteristic of this kind of wetland). The sedge survived and grew so well that after two years, it could not be distinguished from the sedge in undisturbed areas.
"The Highway 89 project is the most successful wetlands mitigation project i've ever worked on," says Craig Martz, a botanist at California's Department of Fish and Game.
Photo Credits - California Department of Transportation
How do you build a bridge over a wetland without bringing in environmentally-damaging heavy equipment?
"End-on" construction is one answer. In 1991, the Louisiana Department of Transportation and Development used this ingenious method to extend Interstate 310 across a wetland near New Orleans.
End-on construction is a "top-down" technique. Heavy equipment is not placed on the ground--it's placed on top of work platforms mounted on concrete piles. From these platforms, a crane drives piles and pushes the bridge viaducts forward one bay at a time. Once a bay is completed, the crane "crawls" forward onto the next work platform to repeat the cycle.
Building nearly two miles of twin elevated highways over a southern Louisiana swamp was no easy task. The subsurface wetland in this part of the state provides little frictional resistance to piles, and test piles could be driven at only one end of the route. The contractor hired a consultant from Houston to recommend the pile lengths as they were driven, and a geotechnical consultant to help plan the other pile-driving operations.
Delivery of precast construction materials was another challenge for the I-310 contractor. The nearest commercial suppliers were three to five hours away, and the two bridges lacked space for stockpiling such materials. So the contractor bought a vacant maintenance yard a few miles away and built a precasting plant.
Planning the end-on construction project was the biggest challenge, however. "It took us a whole year to think it out," says O.V. "Ole" Krasts, Operations Manager at T.L. James & Company, Inc., the I-310 contractors. "Our advance work paid off. We were prepared for every circumstance, and we finished the job way ahead of schedule."
The end-on work took only 485 days.
Hurricane evacuation route and home for alligators
I-310 is the primary hurricane evacuation route for the coastal areas south of New Orleans, connecting I-10 and U.S. Highway 61. The new highway crosses part of LaBranche Wetlands, an important nursery habitat for marine-dependent fish and shellfish species, wintering habitat for migratory waterfowl, and foraging habitat for wading birds.
The construction work did not appear to disrupt animal life. Visitors to the site report that the two resident bald eagles are still there and alligators still forage and rest under the bridge.
Photo Credits - Louisiana Department of Transportation
Sometimes, when a new wetland can't be created off-site because the chosen mitigation site is too expensive, it can be developed on private property, as a no-cost benefit to the property owner.
This was the approach used in a Highway M-53 mitigation project, after the Michigan Department of Transportation had tried unsuccessfully to purchase a mitigation site from a willing seller at a reasonable price. Highway officials were unwilling to pay the high price demanded by the seller, so they found a property owner, Roger Gustafsen, who was willing to have a wetland created on his land, at no cost to him.
The agreement signed by the property owner and the transportation department stipulated that the property owner would preserve the 2.2-acre (0.9-hectare) wetland in perpetuity for the benefit of fish and wildlife. Michigan's Department of Transportation was responsible for all construction costs but would not be charged for the land.
"The highway people were so thorough in their planning, I knew the project would be a success," says Roger Gustafsen, the landowner.
Gustafsen describes the land before mitigation as "pretty useless" for wildlife. After mitigation? "All of a sudden we had thousands of frogs," he says, "and ducks and geese now spend the winter here." Gustafsen adds: "The pond is also great for ice-skating!"
Photo Credit - Michigan Department of Transportation
Minnesota's largest wetland mitigation site, 670-acre (271-hectare) Rice Lake, is also its most successful, thanks to the funding and planning of the Minnesota Department of Transportation.
Rice Lake is located four miles south of Staples, Minnesota, in Todd County. The lake is actually a lake "basin" filled with water, monitoring wells, dikes, and 30 "islands"--islands created as safe havens for nesting waterfowl.
The wetland was "prime" for restoration. In 1905, Rice Lake was drained, and within a few years, the lake basin became simply Todd County Judicial Ditch Number 20. Incomplete drainage forced farmers to abandon their plans to cultivate the area, and in 1961, the county board sold the land to the Department of Natural Resources (DNR) for only $1 an acre ($2.47 a hectare).
In 1970, the DNR sought the help of the Soil Conservation Service to begin restoring Rice Lake, but limited funds and 120 acres (48.5 hectares) of private land remaining in the basin stalled the project.
The Minnesota Department of Transportation (MNDOT) entered the picture in the mid-80's, and prospects began to brighten. Under the state's newly-created Mitigation Habitat Banking program, MNDOT arranged to purchase the 120 acres and transfer ownership to DNR.
Public involvement and inter-agency cooperation were key to the project's success. A local citizens' group called the Staples Sportsmen's Club persuaded the Todd County Commissioners to grant the necessary construction permits. And the U.S. Army Corps of Engineers joined forces with four state and federal agencies (MNDOT, MNDNR, the Federal Highway Administration, and the U.S. Fish and Wildlife Service) to get the necessary funding.
Rice Lake was restored and visibly successful even before most of the mitigation losses had taken place. Within days, Canadian geese, egrets, spotted sandpipers, and other waterfowl returned to the lake basin. Unexpectedly, non-waterfowl species such as songbirds and muskrats also swarmed to the area. "We witnessed a tremendous biological explosion," says Larry Foote, Director of Environmental Services at MNDOT. "Even declining species, like the sandhill crane, came back."
Gary Johnson, Area Wildlife Manager at the DNR, urges those involved in wetland mitigation to "repeat your message over and over," and to "keep an open mind." "Trust DOT to do its job," he says." "Don't worry about procedural differences (for example, a different bidding process)." Johnson also urges transportation planners to be willing to do environmental monitoring after mitigation is completed.
Photo Credits - Kueberg
State Line Bog, Dead Dog Bog
Bogs are decaying, muddy, swampy places, right? Not State Line Bog and Dead Dog Bog in southern Mississippi.
These two bogs cover 360 acres (146 hectares) in Greene County. Thanks to a successful wetland mitigation banking project, they're anything but "dead". They're filled with fresh, clean water and they harbor eight rare and endangered animal and plant species.
The wetland on which the bogs are located used to belong to Scott Paper Company. The Nature Conservancy took advantage of tax benefits available to "in-kind" exchange of property and traded an Alabama tree farm for the company-owned wetland. "Our wetland was useless as timberland, so this was the perfect solution," says Charlie Manogue, operations manager at Scott Paper. "They got the bogs, and we got a nursery site for 19 million seedlings."
In 1990, the Mississippi Highway Department bought the bogs, which needed to be restored, and in cooperation with the Nature Conservancy and the Department of Wildlife, Fisheries, and Parks (DWFP), set up a bank to offset wetland losses along Highway 98 and future road projects. Once the bogs have been restored, the land title will be transferred to the DWFP, and the bogs will remain a state-owned nature area held in trust for the public.
Graceful, leather-like pitcher plants, which attract and feed on insects, are the mainstay of the bogs. Had the bogs not been restored, these blooming plants might have disappeared, because overgrowth blocked necessary sunlight and drainage ditches removed water from the soil. Engineers had to fill ditches and burn off the pine trees and scrub brush surrounding the bogs. "One year after burning, it didn't look like the same place," says a pleased Ken Gordon, Coordinator of the Mississippi Heritage Program.
Gordon doesn't think the restoration would have happened without inter-agency cooperation. It's the kind of cooperation in which people don't just give in to the 'popular' thing,' he says. "They ask, 'Isn't there another way?'"
Blackfoot Waterfowl Protection Area
A 1000-acre (404.7-hectare) Montana ranch in the Blackfoot River floodplain was the focus of a 1988 cooperative mitigation agreement involving The Nature Conservancy, the U.S. Fish and Wildlife Service, the Montana Department of Fish, Wildlife and Parks, and Ducks Unlimited, the Montana Department of Health and Environmental Sciences, the Montana Department of Transportation, the Federal Highway Administration, and the Environmental Protection Agency.
The meeting occurred at just the right moment. The U.S. Fish and Wildlife Service wanted land for waterfowl production, the Federal Highway needed a site for mitigation of wetland impacts caused by Montana Highway 200, and the owner of the ranch wanted to sell his property. A development company was interested in buying the ranch, so quick action had to be taken.
The parties who sat at the table came up with an ingenious and innovative solution:
"Inter-agency cooperation was critical to the project's success," says Steve Potts, an environmental engineer at the Environmental Protection Agency. "Without it, we wouldn't have received the necessary funding."
Bob Kiesling, co-founder of American Conservation Real Estate and former director of Montana's Nature Conservancy, agrees. "We built a consensus by identifying the need--the threatened wetland, our different priorities, and the best available mitigation plan."
Duck population doubles
The sagebrush-covered ranch, bounded on one side by the Blackfoot River, was an ideal site for waterfowl production, because it was made up of shallow marshes, natural springs, and grassy uplands (necessary for bird nesting cover). The Ducks Unlimited contractor enhanced the area and enlarged the wetlands by adding dikes and by revegetating the uplands, at a cost of only $1,000 an acre.
In all, more than 100 acres (40.5 hectares) of existing wetlands were restored or enhanced (far and above what existed at the start).
The result? Ducks swarmed to the area, and their numbers doubled. Other wetland-dependent wildlife has also flourished. For example, greater numbers of deer, elk, and other species have returned to the revegetated upland areas. The Blackfoot Waterfowl Production Area has also become a popular recreation spot for bird-watchers, photographers, hikers, and others.
Photo Credits - FHWA
Imagine a large lowland forest filled with red and silver maple, water oak, cypress, persimmon, American elm, sycamore, and other trees--many of them 80-100 feet (24-30 meters) high. Then imagine that same forest populated with wood ducks, mallards and 12 other species of waterfowl. Picture a floodplain on the wet forest chock-full of striped bass, blueback herring, and shad.
One high-quality hardwood forest fitting this description is Company Swamp, located on 1031 acres (420 hectares) in the North Carolina Coastal Plain, along part of the Roanoke River. Today, it's the largest intact and least disturbed example of bottomland forest in the Mid-Atlantic region, but in 1985, it was in imminent danger of being cut for timber harvest.
Together with three other agencies, the NC Wildlife Resources Commission, the U.S. Fish and Wildlife Service, and the NC Nature Conservancy jointly created a mitigation bank to preserve the endangered swamp. The bank allowed the Conservancy to act as a go-between--to negotiate with the landowners (Allegheny International) on the purchase of the wetland and to buy the property at less than its appraised value. The NC Department of Transportation contributed $500,000 to the purchase price of $863,330. Company Swamp remains under ownership of the Conservancy and is available for public use.
Bank provisions are strict. They specify the bank can be used only for mitigation of impacts to threatened bottomland hardwood forests and only for unavoidable impacts where on-site mitigation is not possible. The provisions also include these two specifications:
Photo Credits - North Carolina Department of Transportation
Rogers Interchange, Drayton Interchange
Seasonal ponds or "Prairie potholes" have sometimes been discounted as wetlands, because they aren't wet year-round. Yet they support a wide variety of wildlife, including shorebirds, pheasants, partridges, grouse, and the red fox.
Wetlands like these were formed by receding and melting glaciers. They often look like shallow "pits" or "gouges" in the earth, and they're usually wet in the early spring or after a heavy rainfall.
In North Dakota, a state dotted with prairie potholes, improving an existing highway or building a new one often involves filling or draining one of these wetland areas. When highway engineers replace these potholes, they use designs which enhance such biologically-important features as cover for duck broods, grassy sites for nesting and "loafing," and irregular shorelines for better "edge."
The Rogers Interchange ponds on I-94 are an early example of successful wetlands mitigation in North Dakota. The ponds, built in 1976, have been successful because they contain both deep and shallow water--deep water for diving waterfowl like Canvasback ducks and shallow water for pair and brood habitat. A large natural wetland to the north across the Interstate provides nesting habitat for the divers, who later "walk" their broods into the created ponds through an underpass.
The Rogers Interchange project was part of a study done to evaluate constructed ponds as a means of replacing natural wetland habitat affected by roadwork.
Similar to the Rogers wetlands, the Drayton Interchange pond along I-29 in the Red River Valley is just as important, since there are few wetland habitats in this part of the state.
This project is part of an "easement"--an agreement entered into by a landowner and the U.S. Fish and Wildlife Service (USFWS). And it's part of an easement banking agreement which requires the North Dakota Department of Transportation to replace USFWS wetlands affected by highway construction at a 1:1 ratio, or greater, and then deed the wetlands to USFWS for waterfowl habitats.
Photo Credits - North Dakota Department of Transportation
Carroll Besadny, former Secretary of Wisconsin's Department of Natural Resources, called it "the state of the art in minimizing overall environmental impacts from highway construction."
He was referring to Madison, Wisconsin's four-mile (6.4-kilometer), six-lane South Beltline Freeway. The freeway, which crosses more than 1,000 feet (304.8 meters) of open water and 1,000 feet of restored marsh on a twin 33-span bridge, aroused controversy for two and a half decades. The fact that it got built at all is a tribute to inter-agency cooperation, public participation, and everyone's dogged determination.
The original plan for the South Beltline called for destruction of 71 acres (28.7 hectares) of wetland--and with no mitigation requirements. In 1976, Madison voters approved a referendum requiring the city to oppose the project.
The project was shelved, but not for long. In 1981, rapidly-increasing traffic and congestion and growing numbers of accidents led local officials to pass resolutions supporting highway improvement. Work on the freeway resumed later that year, after the Wisconsin Departments of Transportation and Natural Resources agreed on an innovative mitigation plan which would reduce the wetland requirement by more than two-thirds and would replace lost wetlands with new or restored wetlands (25 acres in all).
According to earlier designs, the half-mile bridge across the marsh would have been built on an earthen embankment. Instead, contractors used less-invasive end-on construction. The approach not only spared waterbirds--it actually attracted them. Ducks and other birds even became a nuisance as they landed on worksite platforms.
A less-invasive lake-dredging technique was also used--a procedure in which dredged fill material was pumped through temporary pipes to the road construction sites. The technique saved taxpayers $1.6 million. Contractors stationed themselves on a filled-in area near the lake and pulled dredged material forward with draglines. Much of the dredged material was then recycled into road embankment. And the lake? a corner of it was deepened to 25 and 30 foot (seven and nine meters) to create diversity and provide a haven for walleye and other fish that need deep water and "slope."
Strict water-control measures were another reason for the South Beltline project's success. For example, engineers dug wells to monitor ground water flow. And they constructed diked "holding ponds" for sediment and piped the water out through a "weir" and an aerator which reoxygenated it. Nothing ecologically-damaging was returned to the wetland.
Throughout the project, not-so-common environmental inventories were taken for baseline information and to measure environmental impacts. One year, in both spring and fall, a university student hired by project designers stood on the site for days at a time, counting the animal and plant species he observed.
During construction, project managers were in constant communication with the public. This proved to be no easy task for George Meyer, construction supervisor at the Wisconsin Highway Department. "Thousands of motorists had no place to go, because the old freeway had no detour," he says, "so we had to do construction in stages, and we had to make frequent Public Service Announcements on the radio telling people which lanes were closed during which hours." Meyer also used a constructed model of the project, several table-lengths long, to show the public what the project would eventually look like.
"I haven't heard a single negative comment about the project," says Meyer. Neither has Mary O'Brien, president of Transportation Environment Management, Inc. and a key player in the drafting of the project's second Environmental Impact Statement. "The local residents I know tell me it's the best project they've ever seen."
Photo Credits - Peggy Lison
Successful mitigation takes time. "Results aren't instantaneous," says Allen Ensminger, owner of Wetlands Wildlife Management Company in DeRidder, LA. "Restoring or creating a wetland takes awhile. Be patient."
Successful mitigation also involves partnerships with resource and regulatory agencies. According to Mickey Heitmeyer, Director of Conservation at Ducks Unlimited, "we need as many partners as we can get."
And successful mitigation requires a holistic view. "Laws and techniques aren't enough," says Calvin DeWitt, professor of Environmental Studies at the University of Wisconsin, Madison. "We have to consider more than just how to get from Point A to Point B. We have to look at behavior and values." "After all," he says, "we're members of a larger community -- an entire ecosystem."
Carol Browner, Administrator of the Environmental Protection Agency, shares DeWitt's view on protecting wetlands. Says Browner: "Look first to the ecosystem itself, evaluate its needs based on risk, and then tailor workable solutions to those needs through the participation of stakeholders in every phase of the process."
Wetlands scientists and environmental experts stress the same ethically-based approach to protecting wetlands from highway impacts. They ask those who build or use highways to consider the reasons for driving from one location to another. And they recommend strategies that reduce the demand for more cars and more car trips. "We've got to adjust our...development habits and the way we build roads, to co-exist with everything that's out there," says Bruce Babbitt, Secretary of the Interior.
"Look first to the ecosystem itself, evaluate its needs based on risk, and then tailor workable solutions to those needs through the participation of Stakeholders in every phase of the process."
Administrator, Environmental Protection Agency
for more information...
U.S. Department of Transportation
Environmental Protection Agency
U.S. Army Corps of Engineers
Department of Commerce
U.S. Fish and Wildlife Service
Questions and feedback should be directed to Mike Ruth (Mike.Ruth@dot.gov, 202-366-9509).