Planning for Sea Level Rise: U.S. Army Corps of Engineers Policy

Abstract

The U.S. Army Corps of Engineers (Corps) was involved with billions of dollars worth of hurricane and storm damage prevention, ecosystem restoration and other coastal engineering projects in 2001. Current public policy demands that the Corps evaluate the economic benefits and costs of its projects over a projected fifty-year life span. With the current trend in global warming and the resulting rise in eustatic sea level, public awareness of the importance of sea level change considerations has increased dramatically. Corps policy on how to assess and apply sea level change to coastal engineering projects is critical to proper economic analyss of projects as well as to project success. Recognizing that relative sea level change is potentially more important to coastal engineering projects than eustatic sea level change, the Corps bases its policy on an assessment of the risk of accelerated sea level rise as compared to observed historic trends. It applies these considerations to every coastal and estuarine (as far inland as the new head oftide) feasibility study that the Corps undertakes. In accordance with suggestions in the National Research Council's 1987 report on sea level change, Corps feasibility studies consider which design alternatives are most appropriate for a range of possible future rates of rise. The feasibility studies then use risk/sensitivity analysis to quantify the benefits and costs of design alternatives. These design alternatives should include those based on the observed historic trend in sea level change and those based on various possible accelerated rates of change. 1 Chief, Water Resources and Coastal Engineering, U.S. Army Engineer District, San Francisco, 333 Market Street, Suite 721, San Francisco, CA 94105 USA, kevin.knuuti@usace.anny.mil