The Costs and Sustainability of Ongoing Efforts to Restore and Protect Louisiana’s Coast

Abstract

The coast is the most vital economic region in Louisiana and is being affected greatly by land loss. The Coastal Protection and Restoration Authority (CPRA) is an overarching agency responsible for planning, coordinating, and implementing restoration and protection projects in the Louisiana Coastal Zone. CPRA publishes the Louisiana Coastal Master Plan (LACMP), a living document that is revised every five years according to new information from science and models. We overview the major processes involved with coastal restoration planning in Louisiana and the various types of restoration approaches and tradeoffs between them. The LACMP has co-evolved with numerical modeling tools that allow managers to identify tradeoffs between objectives that are sometimes at odds, such as: restoring natural processes to sustain ecosystems in the delta, and promoting economic development in the working coast. Marsh creation and river sediment diversions are two contrasting approaches that have the greatest potential for land building within the coastal zone. Both marsh creation and river diversions require a vast amount of energy and capital during implementation. Marsh creation requires large amounts of fuel for each unit of sediment delivered to a marsh and the costs are subject to changes in energy prices. River diversions, however, use gravitational energy to move sediment and are more sustainable in the long term, especially in an energy-constrained future. There are significant financial limitations on the LACMP that could be exacerbated by fluctuations in energy markets. An appropriate next step for the CPRA would be to incorporate energy forecasts into the planning process. Doing so might illuminate sustainability risks not yet considered by coastal planners.