WASHINGTON, D.C., June 27, 2001 — A government program that allows developers to fill in wetlands in exchange for restoring or creating others nearby needs to be improved to meet the goal of 'no net loss' in size and function of wetlands, says a new report from the National Academies' National Research Council.
Before granting permits to fill natural wetlands, regulators should give greater consideration to how restored or newly created wetlands can replicate the ecological functions of naturally occurring wetlands and become a sustainable part of the larger watershed, said the committee that wrote the report.
"A broader geographic area needs to be considered when deciding which wetlands to restore and where to place new wetlands so they continue to serve the ecological needs of the entire watershed and have a higher chance of long-term survival," said committee chair Joy Zedler, professor of botany and Aldo Leopold Chair of Restoration Ecology, University of Wisconsin, Madison.
Wetlands are complex ecosystems such as marshes, swamps, and bogs that sometimes serve several ecological functions including improving water quality, controlling floods, diminishing droughts, and stabilizing shorelines. They also are home to many rare and endangered species of plants and animals as well as species of commercial and recreational value. Before the ecological value of wetlands was recognized in the 1970s, they were often destroyed indiscriminately to promote agriculture, build homes and businesses, and control mosquitoes. By the 1980s, the wetland area in the contiguous United States was about half what it had been in the 1780s.
The Clean Water Act prohibits the discharge of soil and sand into waters of the United States — which by definition include most wetlands, according to the U.S. Army Corps of Engineers and U.S. Environmental Protection Agency (EPA) — unless authorized by a permit issued under Section 404 of the act. Only the Corps and some EPA-approved state programs can issue such permits. The Corps requires permit applicants first to steer clear of, and at least minimize damage to, wetlands. If unavoidable damage cannot be minimized, the Corps requires the permit holder, or a third party paid by the permit holder, to restore, create, enhance, or preserve nearby wetlands as compensation for the damage. This "compensatory mitigation" is intended to comply with the general goals of the Clean Water Act, and the more specific goal of "no net loss" of wetlands that the White House called for in 1989. An agreement between the Corps and EPA emphasizes that no net loss means no loss in acreage or ecological function.
From 1986 to 1997, the annual rate of wetland loss in the contiguous United States decreased by 77 percent from the previous decade, and some of this decrease may come from developers being deterred by the Section 404-permit process, the committee said. However, despite progress in the last 20 years, the goal of no net loss for wetland function is not being met. From scientific literature, expert presentations, and site visits, the committee found that some required mitigation projects are never undertaken or are not completed. Of those completed, most are not fully evaluated, and in the ones that are, the committee and other scientists found shortcomings compared to nearby natural wetlands. The magnitude of the loss of wetland function is not precisely known since not enough data are kept on the ecological status of wetlands that are lost or those that are restored or created.
Likewise, because of insufficient data, it was impossible for the committee to determine whether there has been no net loss of wetland acreage. From 1993 to 2000, about 24,000 acres of wetlands were allowed to be filled, and 42,000 acres were required as compensatory mitigation, meaning nearly 2 acres should have been gained for every 1acre lost. However, the lack of data prevented the committee from determining if the required compensation was ever initiated or if it resulted in wetlands that would be recognized as such under federal guidelines.
To better understand the efficacy of the mitigation program, the Corps should create a national database to track the wetland area and functions gained and lost and to encourage the establishment of organizations to monitor mitigated sites, the committee said.
Whenever possible, restoration of a natural wetland should be chosen over creation of a new one, the committee said. It emphasized that wetland restoration or creation will be most successful when properly integrated into the larger watershed. Current federal guidelines express a preference for putting new wetlands as close as possible to degraded ones, however the committee concluded that this is not always the best choice. Rather, creating new wetlands in areas with proper water levels and flow rates is the key to achieving a self-sustaining wetland that will stand the test of time. Adaptive management practices should be followed, allowing changes to be made to the wetland based on results of early monitoring.
Some types of wetlands, particularly bogs and fens, cannot yet be effectively restored, so the agencies should not allow any part of them to be filled, the committee said.
Whether mitigation is carried out by the permit holder or a third party, restoration or creation of a wetland should occur simultaneously or before the filling of the natural wetland and according to established design criteria that are better monitored and enforced, the committee said. To ensure long-term stewardship similar to that accorded to other publicly valued assets, like national parks, the permit holder or third party should provide a stewardship organization, such as a state agency or private organization like the Nature Conservancy, with an easement on or title to the wetland site and funds for the long-term monitoring and maintenance of the site. It may take 20 years or more for some restored or new wetlands to achieve functional goals, the committee noted.
"Enforcement of these requirements by the Corps and other responsible agencies is needed to ensure that mitigation projects begin on time, meet the design criteria outlined in the permit, and are monitored long term," said committee vice chair Leonard Shabman, professor, Virginia Polytechnic Institute and State University, and director, Virginia Water Resources Research Center, Blacksburg.
The report was sponsored by the U.S. Environmental Protection Agency, the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service, and the National Marine Fisheries Service. The National Research Council is the principal operating arm of the National Academy of Sciences and National Academy of Engineering. It is a private, nonprofit institution that provides scientific and technical advice under a congressional charter. A committee roster follows.
Read the full text of Compensating for Wetland Losses Under the Clean Water Act for free on the Web, as well as more than 1,800 other publications from the National Academies. Printed copies are available for purchase from the National Academy Press Web site (http://www.nap.edu) or by calling (202) 334-3313 or 1-800-624-6242. The Academies' Web site also features supplemental information and an extended Web treatment at http://national-academies.org/webextra/wetlands.
