Estimating Surge-Based Flood Risk with the Coastal Louisiana Risk Assessment Model

The Coastal Louisiana Risk Assessment model (CLARA) was designed to facilitate comparisons of current and future flood risk under a variety of protection system configurations in a wide range of environmental, operational, and economic uncertainties. It builds on previous studies of coastal risk by incorporating system fragility and a larger number of future scenarios than previously analyzed. Flood depths and direct economic damage from a wide range of simulated storm events are aggregated to produce a statistical summary of coastal risk under different assumptions about future conditions. CLARA's estimates of project-level effects on flood risk reduction were used as one of the key decision drivers in selecting the risk reduction projects included in the Master Plan. Depending on the scenario, the final alternative is projected to reduce expected annual damage by approximately 60 to 80% during the next 50 years relative to a future without action and, at the same time, balance other decision criteria.