It is particularly critical of so-called "mitigation" provisions that allow developers and others to fill in or destroy wetlands by restoring or creating new wetlands in other locations, saying the government has fallen far short of the goal of "no net loss" set by President George Bush in 1989.
Further, it says, the government has failed to keep track of wetlands to see if losses due to development are properly mitigated.
Sponsors of the report included the 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 is a private, non-profit institution that provides scientific and technical advice under a congressional charter.
After reviewing hundreds of mitigation projects, the panel reported that many were never even started, others weren't completed, and those that were finished left much to be desired in terms of being functioning wetlands.
In drafting the original wetlands regulations, scientists noted that these complex ecosystems — including marshes, swamps, and bogs — serve to improve water quality, control flooding, diminish drought, and stabilize shorelines, as well as providing habitat for many endangered species of plants and animals.
By the 1980s, scientists estimated, the wetland areas in the contiguous U.S. were about half what they had been in the 1780s.
From 1986 to 1997, the annual rate of wetland loss in the contiguous U.S. dropped by 77 percent over the previous decade, the report says. In southern California, it is estimated that development has caused the loss of more than 90 percent of coastal wetlands.
"Some of this decrease may come from developers being deterred by the Section 404 permit process, but despite progress in the last 20 years, the goal of no net loss for wetland function is not being met."
It's hard to accurately assess the level of progress, the committee of scientists said, "since not enough data are kept."
Nearly two acres should have been gained during the period for every acre lost, they note, "but the lack of data prevented (us) from determining if the required compensation was ever initiated or if it resulted in wetlands that would be recognized as such under federal guidelines."
"On paper, it looks like there is a net increase," says the committee chairperson, Joy Zedler, professor of botany at the University of Wisconsin, "but in actuality, it appears there's a loss of acreage."
One thing's sure, the committee agreed: Many of the mitigation wetlands aren't designed to last and often bear little resemblance to those they were supposed to replace.
To better track the workings of the mitigation program, the Corps of Engineers should create a national database to monitor wetlands and functions that are gained and lost, the committee recommends. And it says the agency should "encourage the establishment of organizations" to monitor these sites.
Whenever possible, it says, restoration of a natural wetland should be chosen over creation of a new one, and new wetlands should be created, where possible, in areas "with proper water levels and flow rates…to achieve a self-sustaining wetland that will stand the test of time."
Some types of wetlands, particularly bogs and fens, "cannot yet be effectively restored, so the (regulating) agencies should not allow any part of them to be filled."
And, the committee says, restoration or creation of a wetland "should occur simultaneously or before the filling of the natural wetland, and according to established design criteria that can be better monitored and enforced."
To insure long term stewardship of the wetland "similar to that for other publicly-valued assets like national parks," the committee recommends that a stewardship organization, such as a state agency or a private organization such as the Nature Conservancy, be given an easement or title to the site and funds for long term monitoring and maintenance.
"It may take 20 years or more for some restored or new wetlands to achieve functional goals," the committee said. "Enforcement of these requirements by the Corps and other responsible agencies is needed to insure that mitigation projects begin on time, meet the design criteria outlined in the permit, and are monitored long term," said committee vice chairman Leonard Shabman, professor at Virginia Polytechnic Institute and State University and director of the Virginia Water Resources Center at Blacksburg.