The integration of nonstructural methods into flood loss reduction programs:an evaluation of a remaining obstacle

Current U.S. Army Corps of Engineers water resources planning guidance directs the planners to consider all design alternatives with economic efficiency as the primary criterion. Recent criticism of the flood loss reduction planning is directed at the Corps. One criticism is that the traditional design practices of the Corps address only large flood events. The emphasis on large flood events precludes the use of nonstructural methods, whose economically feasible range is at smaller scales. However, the advantage of having nonstructural measures available to federal water resources planners is widely recognized.

This study seeks to demonstrate that nonstructural means are at a disadvantage in the Corps planning process. It examines the institutional framework that directs the planning of these projects. Using data from Corps reports, the economically feasible ranges and optimal sizes are determined for selected nonstructural measures through a series of case studies. The resulting optimal sizes are compared to those recommended in the Corps reports.

The optimal sizes of the nonstructural alternatives developed for this study are smaller than the recommended levels. In the current budget climate, the implementation of flood loss reduction projects may occur more frequently with the increased use of nonstructura1 measures since they require less investment.