Louisiana Coastal Protection and Restoration Authority

Louisiana 2017 and 2023 Coastal Master Plans

The Water Institute has been involved in nearly all aspects of Louisiana’s $50 billion, 50-year, Coastal Master Plan (CMP) updates. Between each CMP cycle, The Water Institute leads modeling tasks to improve the functionality, resolution, and performance of the suite of models used for ecosystem restoration and flood risk reduction analysis. The CMP, updated every six years, advances a comprehensive, integrated approach to prioritize projects and investments to make Louisiana’s coast resilient and sustainable.

The Approach

In each CMP, The Water Institute provided CPRA with the coordination, scientific expertise, and numerical tools needed to evaluate and prioritize large-scale restoration efforts for coastal Louisiana. The Water Institute worked collaboratively to co-develop the Integrated Compartment Model (ICM), Louisiana’s custom tool for predicting environmental changes within its delta and chenier plain wetlands. The ICM allows the state to look decades into the future through the use of interconnected hydrodynamic, geomorphologic, and ecologic (both vegetation and species habitat suitability indices) sub models. The Water Institute also updated the input datasets and boundary conditions, conducted an uncertainty analysis, and managed improvements to seven modeling components (sediment distribution, marsh edge erosion, vegetation, barrier shoreline, ecosystem outcomes, storm surge and wave, and risk assessment).

For the 2017 CMP, in addition to its model development and technical analysis role, The Water Institute managed the contracting and technical activities of the entire modeling team, which was comprised of a diverse set of academic, non-profit, and private institutions. The Water Institute enhanced existing and developed new and innovative numerical tools to yield a deeper understanding of Louisiana's current and future 50-year coastal environment.

For the 2023 update, the Institute is supporting all risk reduction modeling (storm surge and waves) utilizing coupled ADCIRC and SWAN models. The Water Institute is applying its storm surge expertise to explore nuisance/high frequency flooding in Louisiana’s low-lying areas given the combination of rising seas and subsiding wetlands. The Water Institute assists CPRA in the operation of the ICM and is leading the creation of the Barrier Island System Management (BISM) model, which will be an ICM companion model framework focused on Gulf barrier shoreline morphology prediction over decadal timescales. Through The Water Institute’s multifaceted involvement in the 2023 CMP, we are uniquely positioned to understand the feasibility and alternatives analyses aspects of nature-based solution proposals aimed at increasing the resilience of coastal Louisiana in the coming decades.