San Francisco Chronicle
Despite a decade-old pledge, the U.S. government is failing to ensure
that developers who destroy wetlands are restoring or creating
replacement habitats, according to a recent report by a science
The panel, an advisory council to the National Academy of Sciences, found that construction of substitute wetlands has often been delayed or never completed. Many projects that were finished have failed to serve the function of natural wetlands, and there has been little follow-up to insure that the artificial wetlands do not silt up or become weed-choked.
The report casts doubt on the effectiveness of a 1989 program of the U.S. government that allows landowners to fill natural wetlands in exchange for a commitment to restore degraded wetlands or create artificial ones. The goal of "no net loss" has not been met, the report concluded, and the country continues to lose more of its valuable swamps, bogs, tidal marshes, and ponds each year.
Meanwhile, many projects to create artificial wetlands have not been successful, the panel said. "So many of these projects fail because nature never intended for there to be a wetland there, or a particular type of wetland there," said Suzanne van Drunick, director of the study prepared for the National Academy's National Research Council.
Natural wetlands filter pollution, aid flood control, and provide wildlife habitat for many plants and animals, some of them rare or endangered. The report found that many substitute wetlands built in exchange for filling in natural ones lack those important functions.
Since the late 1700s, the United States has lost about 50 percent of its wetlands in the lower 48 states, historically to farmland and more recently to development. But overall, the panel found that the rate of wetlands destruction had dropped sharply since the 1970s. Still, the nation lost nearly 60,000 acres of wetlands a year from 1986 to 1997.
It's a similar story in the Bay Area, where San Francisco Bay has shrunk by about a third from its size prior to the Gold Rush. The bay was losing about 350 acres a year before tougher environmental protection laws were passed in the 1960s. Now, dozens of restoration projects are being planned or are under way throughout the Bay Area to return thousands of diked and filled acres to a natural state.
Nonetheless, the state of the region's wetlands has come under intense scrutiny recently.
In what would be the largest public works project in decades, officials at San Francisco International Airport are studying a project that could fill in another two square miles for new runways. To compensate for the loss, San Francisco officials have pitched the idea of paying hundreds of millions of dollars to restore wetlands currently used for salt production, mainly in the South Bay.
But the report highlights a nationwide problem in attempting to create or restore wetlands. When carving out a wetland, "the easy thing to do is to create an open-water pond with cattails around it," said van Drunick. "That's the trend."
"[The ponds] are pretty to look at and have some function, but they don't have the same functions as the ones that were lost," she added.