The U.S. Army Corps of Engineers studies the potential costs and benefits of flood risk management projects—such as levees, floodwalls, or building relocation—to inform decision makers about their potential economic effects.
The Government Accountability Office reviewed 8 Corps studies and found they followed many best practices. But the analyses were not always transparent. For example, only one study considered the limitations of the computer model used in a flood damage analysis. Without that information, reviewers can’t make the best decisions on which projects would be most beneficial.
GAO recommended the Corps strengthen its internal review process to ensure decision makers have all the information they need.
In the eight studies GAO reviewed, the Corps typically recommended the alternative plan with the greatest net benefit, but also relied on other analyses in certain cases, as allowed under Corps guidance. Corps officials said they relied on other analyses to determine the best project design, help make decisions, or respond to local sponsors’ preferences. For example, in one study, the Corps recommended a plan that provided a levee 3 feet higher than the plan with the greatest net benefits, in response to the nonfederal sponsor’s request.
The Corps’ economic analyses in the eight studies were generally consistent with best practices, but did not fully adhere to practices for transparency. For example, most analyses did not discuss the implications of key limitations in the models and data used. Corps officials acknowledged that transparency could be improved through their review process. By having future analyses align with transparency best practices, the Corps can better inform decision makers about potential economic effects of flood risk projects.
GAO was asked to review the methodology the Corps used in feasibility studies. This report examines, for 2015 through 2017, (1) the Corps’ process for identifying and evaluating the benefits, costs, and effects of project alternatives; (2) the analyses the Corps used to recommend projects; and (3) the extent to which the Corps’ economic analyses of benefits and costs are consistent with best practices.
GAO recommends that the Corps strengthen its feasibility study review process by including steps to ensure consistency with transparency best practices. The agency concurred with the recommendation.
