are no data on how much of the mitigation was by created or restored wetlands. Therefore, one cannot draw firm conclusions about such changes in wetland area.

For every 100 acres of permitted fill, 178 acres of wetland were to be restored, created, enhanced, or preserved. However, these data report the mitigation required as a condition of the permit. There are no data on whether the required compensation was initiated. Nor are there data on whether the initiated compensation resulted in a wetland that would be recognized by the jurisdictional criteria used by the Corps or by FWS approach to wetland identification.

Assuming that most mitigation that has been required by the Corps was initiated and resulted in jurisdictional wetlands, the Section 404 program has achieved no net loss of wetland area. This would mean that wetland losses to urban and rural development, as reported by FWS, are occurring outside the scope of the Section 404 program. If this is the case, the program may be discouraging wetland-damaging activities (see above) and is more than replacing the wetlands when such activities are permitted. From this perspective, continued wetland loss to urban and rural development would have to be addressed by expanding the Section 404 program or by some other means. If, by contrast, it is assumed that little of the required mitigation is undertaken in a way that replaces lost wetland area, the acres permitted by the program are about equal to the acres lost to urban and rural development.

The committee is unable to determine the precise extent to which compensatory mitigation is initiated and results in wetlands that would be identified by the FWS inventory process. Indeed, there are no data that would support such an assessment. However, the preceding paragraph does highlight the importance of effectively implementing the required compensatory mitigation when wetland permits are issued. The committee recognizes that the Corps districts now do routinely require mitigation. Hence, this report focuses on increasing the likelihood that this legal requirement will be implemented by those responsible for compensation and that their efforts will result in wetlands that provide important functions in the nation's watersheds.

THE COMMITTEE'S TASK

The Committee on Mitigating Wetland Losses (see Appendix J) was established by the National Research Council, Division on Earth and Life Studies, under the aegis of two boards: the Board on Environmental Studies and Toxicology and the Water Science and Technology Board. The committee's Statement of Task, in the context of Section 404 of the Clean Water Act, is the following:



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