Expert Report

Final Report from the NRC Committee on the Review of the Louisiana Coastal Protection and Restoration (LACPR) Program (2009)

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This second and final report from the National Research Council on the Louisiana Coastal Protection and Restoration (LACPR) Program reviews a 2009 draft report from the U.S. Army Corps of Engineers on hurricane protection and coastal restoration for southern Louisiana. The National Research Council finds that the lack of a comprehensive protection and restoration plan for southern Louisiana constitutes a major shortcoming in the Corps' report. It recommends that, before the end of 2009, the Corps and the State of Louisiana agree on the elements of a long-term plan and on a number of high-priority protection projects (such as levees and zoning plans) and restoration measures (for example, the creation or enhancement of wetlands or barrier island) projects for immediate implementation.

Key Messages

  • There is a need for more detailed description of sediment availability, including better justification for the assumption that the current shoreline can be maintained in place.
  • LACPR draft final technical report does not adequately demonstrate how these principles will be a prominent part of hurricane protection and coastal restoration actions. Discouraging development in particularly vulnerable areas, whether or not they are protected by levees, is a fundamental principle of flood risk management and reduction.
  • Multi-Criteria Decision Analysis is a potentially useful approach to evaluate projects with important environmental, social, and cultural impacts; however, flaws in the application of these methods to the LACPR study have prevented any convincing results. As applied, the methods do not support the identification of a preferred alternative for any of the planning areas. Furthermore, they do not support the rankings of alternative plans as presented in the LACPR report.
  • The LACPR report should provide a better and more quantitative explanation of the scientific uncertainty associated with projections of marsh and wetlands restoration (including diversions), surge attenuation by wetlands, numerical modeling efforts, and the implications of Mississippi River diversions.
  • The high level of uncertainty of the effects of proposed river diversions suggests the need for careful monitoring and evaluation of existing diversions.
  • The multiple authorizations that govern ecosystem restoration and hurricane protection in southern Louisiana represent a piecemeal approach and may hinder integrated, adaptive restoration and protection improvements across the region.
  • There should be a more explicit acknowledgement of ongoing and future coastal erosion trends and their implications for restoration priorities.