NCHRP Report 379, "Guidelines for the Development of Wetland Replacement Areas," describes a process for locating, designing, constructing, maintaining, and monitoring wetland replacement areas. This report is supplemented by appendixes that describe various aspects of wetland creation and restoration. The Guidelines will be of interest to those involved with wetland replacement areas (e.g., engineers, environmentalists, planners, and regulators), both as a concept and as an actuality, once it is obvious that the creation of a replacement wetland is necessary. Although not explicitly within the scope of this study, the Guidelines also will be useful to those involved with wetland banks -- the development of wetlands that could be used to compensate for future takings elsewhere.

Planning for highway projects frequently involves consideration of several mitigative alternatives to address adverse impacts to wetland resources. One alternative often used requires the development of wetland replacement areas as compensation for wetlands lost because of highway development projects. Although considerable information was available on the subject of wetland replacement -- both in documented form and in undocumented experience and practice -- much of this information was fragmentary and dispersed throughout the country, or it had not been fully evaluated. Therefore, current information could not easily be used for locating, designing, constructing, maintaining, or monitoring wetland replacement areas. To ensure effective implementation of this important mitigative alternative, transportation planners, designers, environmental staff, and other users needed ready access to this information. Therefore, there was a need to synthesize the state of the art and, from this synthesis, to develop a recommended process for replacing wetlands.

Accordingly, URS Consultants, Inc., along with Environmental Concern, Inc., developed recommended guidelines. The Guidelines contain a well-defined wetland replacement process. The Guidelines also will be helpful to those wishing to create wetland banks that could be used for trade at a later date when the elimination of an existing wetland is unavoidable. The Guidelines are not intended as commentary on the merits of wetland banking to mitigate the unavoidable elimination of wetlands; however, if a decision is made to implement a wetland bank, the Guidelines will be useful in the physical creation of the compensating wetlands.