The National Academy of Sciences has appointed a committee of the country's top scientists to peer review the coastal protection and restoration plans of the Army Corps of Engineers in Louisiana. The National Academy of Sciences is the scientific adviser to the federal government.
At a meeting on Thursday April 3, 2008, the National Academy peer review committee and the Corps held a public meeting concerning the peer review committee's work. The peer committee was critical of the Corps' plans in a number of respects.
The question being considered at the meeting was whether the Corps plans to protect and restore the Louisiana coast will work. The National Academy scientists began by questioning the Corps basic strategy which is to maintain the coast as it currently exists. The National Academy scientists questioned why the Corps was not considering other alternatives such as creating new land and allowing some areas to erode.
The National Academy scientists also questioned whether the Mississippi River carried enough sediment today to maintain the coast as the Corps suggests that its plan would do.The scientists seemed surprised and upset that the Corps' representatives did not have a basic knowledge of how much sediment the river carried and had not taken steps to determine if the available sediment was sufficient to achieve the Corps' objectives.
One of the National Academy scientists questioning the Corps was Robert Meade. Meade is retired from the United States Geological Survey. Meade is well known in the scientific community for his knowledge of sediment transport in rivers and particularly in the Mississippi River. The representatives of the Corps might serve themselves well to read some of the scientific articles that Meade has previously published on sediment transport in rivers.
The question of sediment supply in the Mississippi River is critical to the success of any coastal protection and restoration project in Louisiana. The sediment load in the Mississippi River has declined sharply since the 1930's as a result of the extensive construction of dams and locks in the Mississippi River drainage system. Dams trap sediment in the reservoir behind the dam and the locks trap sediment in the slack water pool behind the lock. The most significant sediment transportation reductions have occurred in the Missouri River and Arkansas River which are tributaries of the Mississippi River.
For navigation purposes, sediment in the Mississippi River is a nuisance that requires dredging. Much of the Corps operations in the Mississippi River drainage system are centered upon navigation. This means that for most purposes north of Louisiana on the Mississippi River and its tributaries, the Corps would like to see as little sediment transport in the river as possible. This desire, however, runs counter to the needs of coastal Louisiana. These navigational needs have in the past and continue today to trump the coastal restoration and protection needs of Louisiana. When the Corps considers how it will build and operate projects north of Louisiana in the Mississippi River drainage basin, the sediment transportation needs of Louisiana's coast are not typically considered.
Congress had asked the Corps to deliver the Louisiana Coastal Protection and Restoration Plan in December 2007. Now the plan will not be delivered until December 2008. Further, Congress had asked the Corps to identify a set of coastal protection and restoration projects that could be started quickly. Instead, the Corps has now stated that its December 2008 plan will not "include the specific identification of a detailed plan." Instead, the Corps' report will include aspects that require additional study before Congress can fund and the Corps can begin construction of the projects ultimately included in the plan.
The National Academy scientists led by Robert Dalrymple, a civil engineering professor at John Hopkins University also questioned this "further study" approach. Dalyrmple suggested that Congress might have been trying to create a sense of urgency after Hurricanes Katrina and Rita for more immediate action.
The National Academy scientists also questioned why the Corps report did not include a major diversion of the Mississippi River south of New Orleans as many scientists and environmental groups have recommended. Instead the Corps report will suggest a number of smaller diversions.
For a more detailed description of this meeting, see Mark Schleifstein's article in the New Orleans Times Picayune of Saturday April 5, 2008 entitled: Reviewers Grill Corps on Coast Plans.
Erich P. Rapp.
