Coastal protection groups say levees alone not enough to protect La. coast
In November 2005, the U.S. Congress directed the U.S. Army Corps of Engineers to produce a plan - the Louisiana Coastal Protection and Restoration study - to outline a full range of hurricane protection measures to protect coastal Louisiana from Category 5 hurricanes. The LACPR report, or the "Category 5 plan" as it is sometimes called, was due to be completed by the end of 2007, but the Corps missed the deadline and the plan was not released until June 9, 2009.The long-overdue report, which was supposed to offer a comprehensive storm protection plan to address both coastal restoration and levee building, has since come under heavy criticism for failing to do just that. Last week the National Academy of Sciences peer review committee released a report blasting the Corps' study for not only missing the 2007 deadline, but for offering only "broad" plans and failing to provide clear recommendations. As the Times-Picayune reported, this group of renowned scientists and engineers said the Cat 5 study's lack of a comprehensive long-term plan -- and of projects that could be started immediately -- represented "substantial shortcomings." The Corps has since said it will try to incorporate some of the reviewers' recommendations into the final version of the Cat 5 plan, which will be delivered to Congress by the end of the year.
Coastal protection groups throughout the Gulf Coast have also stepped up to address some of the failings of the Corps' Cat 5 plan, and hope to see the Corps integrate some of their suggestions. A coalition of groups, including the Gulf Restoration Network, have joined together in the Coastal Lines of Defense project, to urge the Corps to include the Louisiana Coastal Lines of Defense strategy in its final report. At its core, Louisiana Coastal Lines of Defense is a strategy that would incorporate multiple coastal lines of defense (see image below) both man-made and natural through "integrating structural protection such as levees and flood gates, with non-structural elements such as home-elevation and evacuation routes along with restored natural defenses such as barrier islands, marshes, natural ridges and cypress swamps," according to the Coastal Lines of Defense project's website.
The groups are encouraging members of the public to send comments to the Corps explaining that levees alone are not enough to defend south Louisiana, and what is needed is a comprehensive approach including the lines of defense strategy. The coastal protection groups are asking the Corps to address the following concerns before the final Cat 5 plan is presented to Congress:
- The LACPR report supports the Coastal Lines of Defense strategy but falls short of applying it to the formulation process and alternatives evaluated. We ask the Corps to incorporate the Multiple Lines of Defense strategy into the analysis.
- The LACPR does not consider the full range of coastal restoration measures, such as using sediment from the Mississippi River, rebuilding barrier islands, restoring cypress swamps and natural ridges, etc.
- Some of the LACPR's levee alternatives could significantly increase storm surge and rely almost exclusively on levees that would enclose almost 1/4 of Louisiana's remaining wetlands. Wetlands behind levees cannot provide protection or a buffer for the levee system and communities inside. The Corps should focus on leaving wetlands outside of the levee systems to act as storm surge buffers.
- Nonstructural solutions (elevating homes, flood-proofing, etc.) are downplayed, despite the fact that they can be implemented quickly and provide cost-effective, environmentally sound risk reduction. The Corps should consider non-structural solutions more seriously.
- Evacuation is a critical element in keeping our communities safe and saving lives, but is not included in any alternatives. The Corps should incorporate evacuation, and all of the lines of defense into their analysis.
- The inevitable interaction of levees, flood gates, barriers, weirs, and leaky levees with diversions is not addressed. Habitat goals for a sustainable coast should be proposed so that the natural function of the estuary is supported.
(The last image illustrates the eleven types of lines of defense, such as barrier islands, ridges, levees, floodgates etc. The strategy also includes vital elements such as "non-structural" techniques, i.e. elevating homes above the potential surge levels. The last line of defense is evacuation routes which allow residents to move from harm's way. From mlods.com.)
