Corps of Engineers Releases Plan for Underseepage Control for Mel Price Locks and Dam

The Corps of Engineers has released its long-awaited plan for correcting a serious uncontrolled underseepage problem in the vicinity of the Mel Price Locks and Dam.  This was a problem uncovered by the Corps in July 2009.   A report outlining the plan, conceptual design, and cost estimate (termed a Limited Reevaluation Report in Corps parlance) can be downloaded here.  When the Corps built the new locks and dam two miles downstream of the old structure, it raised the navigation pool, which increased pressures on the existing levee and resulted in water and foundation material “tunnelling” under the levee during high water events.  This situation, if not corrected, could result in the failure of the levee and the loss of the navigation pool.  Aside from the possibility of significant flooding, commerce on the Mississippi River would be interrupted for a year or more, with economic losses that the Corps estimates at more than $1 billion.

The Corps is proposing to build a cutoff wall through the existing levee and additional relief wells to fix the problem.  The cost of this project is estimated at $31.8 million in April 2011 dollars.  The actual cost of the project, including inflation, will likely be higher, depending on when the Federal government appropriates funding for the project.  Because this problem resulted from the design and construction of the locks and dam by the Corps of Engineers, the entire cost of the project will be paid by the Federal Government.

Until such time as the long-term improvements outlined in the Corps’ plan can be funded and built, the Corps has in place a series of interim measures that can be implemented during high water events.  Unfortunately, this potentially “weak link” in the levee system could affect the Council’s ability to certify the system as meeting Federal Emergency Management Agency standards.  We will be working with the Corps to make the best of this situation and to outline the most effective plan to assure that FEMA standards will be met in time for completion of the remaining levee system improvements sometime in 2015.