RISK REDUCTION IN LOUISIANA'S COASTAL MASTER PLAN: LAKE PONTCHARTRAIN BARRIER

Abstract

The State of Louisiana (LA) Coastal Protection and Restoration Authority (CPRA) conducts extensive analytical modeling and project evaluations across an expansive coastal region along the Gulf of Mexico as part of updates to the State's Comprehensive Master Plan for a Sustainable Coast (CMP) on 5-year recurring intervals. The 2017 CMP includes a combination of 45 risk reduction and 79 coastal restoration projects with projected construction and implementation over a 50-year period through 2065 at a projected cost of $50 billion dollars. Risk reduction includes 13 structural and 32 non-structural projects. Structural risk reduction projects consist of continuation of new construction and maintenance of an extensive system of earthen levees, flood walls, flood gates, and pump stations. Non-structural projects consist of a combination of acquisition, elevating, and flood-proofing of residential and commercial structures within projected coastal storm flood risk areas. The Lake Pontchartrain Barrier structural risk reduction project has projected one of the highest cost-effectiveness (CE) values of all CMP projects. This paper will focus on hydrodynamic and risk reduction modeling performed to evaluate a series of conceptual design alternatives for the Lake Pontchartrain Barrier (LPB).