(e.g., U.S. Army Corps of Engineers), whereas restoration efforts are carried out by another (e.g., U.S. Fish and Wildlife Service or a state's natural resources department). Integrated water and land use planning is needed to restore the essential surface water elevations, flood cycles, water velocities, and (for coastal systems) salinity regimes so that the desired wetland ecosystem can be achieved.
Implementing the president's goal of no net loss of wetland acreage and function will not be cheap. Economic constraints will always limit the location, number, and types of projects that can be implemented. The techniques used to restore wetlands vary widely in cost. Wetlands that are near urban centers are the most expensive to restore because of the cost of land. For example, the city of San Diego recently paid $3.5 million for a 20-acre semitidal wetland that will still need hydrological restoration and topographic modifications. Restoring the 250-acre Ballona wetland (near Los Angeles airport) may cost $50 million, in part because a major roadway through the marsh would have to be elevated so that it would not be inundated by the restored tidal flows. At state and local levels, other demands for land use and funds usually take precedence. Thus, in general, the potential for major restoration projects is currently lower in urban than in rural areas.
Wetlands have been restored in several nonregulatory contexts such as the creation of waterfowl impoundments using water-control structures, the removal of dikes from coastal and estuarine marshes, the blockage of drainage on partially drained agricultural lands no longer used for agricultural purposes, and the grading of gravel pits and other strip-mined lands.
The majority of wetland restoration efforts, however, have occurred as a result of federal, state, or local regulatory actions. In these contexts, private or public landowners seeking permits for various types of development are required either to create, to enhance, or to restore wetlands on-site after damage or to restore wetlands at other sites to compensate for wetland damage at a development site. Few of the Clean Water Act, Section 404 mitigation projects have constituted wetland restoration as defined in this report, and COE and EPA—the two agencies responsible for implementation of the Section 404 program—do not have systematic information about the number of acres of wetlands restored or the effectiveness of particular restoration projects. In the few states for which Section 404 permit records have been surveyed by EPA, the general finding is that mitigation was not