Wetland mitigation isn’t working; reports calls for tough reforms


COLUMBUS – Allowing developers to fill in wetlands in exchange for restoring or creating others nearby isn’t helping the United States meet its goal of “no net loss” in size and function of wetlands.

A new report from the National Research Council says 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.

‘Kidneys’ of landscape.

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.

By the 1980s, the wetland area in the contiguous United States was about half what it had been in the 1780s.

Real loss unknown.

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. The report 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.

In addition to poorly implemented mitigation, wetland monitoring “is seldom required for more than five years,” said William Mitsch, director of the Olentangy River Wetlands Research Park at Ohio State University.

“Up to 20 years may be needed for some restored or created wetland sites to achieve functional goals.”

Mitsch served on the advisory committee for the report.

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.


The report outlined several recommendations for stopping the loss of wetlands including:

* creating or restoring mitigation wetlands before filling the original wetland in;

* choosing wetland restoration over creation;

* designing and constructing individual mitigation sites to maximize the likelihood that they will make an ongoing contribution to the watershed; and

* securing the replacement of lost wetland function by providing effective legal and financial assurances for long-term sustainability and also monitoring all compensatory wetland projects.


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