Maj. Gen. Philip Anderson has officially approved a Mississippi River mainline levee enlargement and seepage control project plan recommended by the Memphis, Vicksburg and New Orleans Districts. Maj. Gen. Anderson, who is Commander of the Mississippi Valley Division and President of the Mississippi River Commission, said he concluded that the recommended plan was the best of all plans considered.

"I find the recommended plan to provide the necessary flood protection, to be the environmentally preferable plan, in the public interest, and in compliance with all federal, state and local requirements," the general said.

The recommendation came after an 18-month study of work remaining to be completed for successful handling of the Project Design Flood. The Project Design Flood is a hypothetical flood having the greatest probability of occurrence. It was developed from past data after the flood of 1927, which was the nation's most disastrous flood. The 1927 flood occurred when Mississippi River levees were breached after storms and prolonged rainfall, flooding 26,000 square miles and causing an estimated 500 deaths.

The flood led Congress to pass the flood control act of 1928, which authorized the Mississippi River & Tributaries project. As a part of this act, all deficient mainline Mississippi River and tributary levees are to be enlarged to protective heights and strength. The MR&T project is scheduled to be completed by 2031 and could be completed as early as 2020, depending on the availability of budget funds.

The plan approved by Maj. Gen. Anderson consists of 128 remaining work items to enlarge and raise almost 263 miles of levees and to construct almost 132 miles of seepage control features along the 1,610-mile mainline Mississippi River levee system from Cape Girardeau, Mo., to the Gulf Coast.

In signing the Record of Decision, Anderson said, "all practicable means to avoid and minimize environmental harm have been adopted. I, therefore, approve the recommended plan for construction."

He said environmental protection measures include "relocating borrow areas from bottomland hardwood forests to less environmentally sensitive areas, where practicable; constructing levees with material obtained from existing berms and utilizing dredged material from the Mississippi River to reconstruct the berms; and using relief wells and cutoff trenches instead of berms to control seepage."

The approved plan also would reforest over 3,000 acres of borrow areas and design 6,727 acres of borrow areas to provide productive aquatic habitat. Compensatory mitigation for unavoidable environmental impacts will be accomplished by the reforestation of about 5,863 acres of frequently flooded agricultural lands.

Anderson said, "the combination of avoid-and-minimize and compensation features will significantly reduce construction impacts that will result in no net loss of wetlands and a net gain of approximately 4,070 acres of bottom-land hardwood forests and approximately 6,727 acres of aquatic habit in the project area."

A monitoring plan will be implemented to assure and document the effectiveness of the reforestation mitigation feature and to evaluate the restoration of wetland functional values. The approved plan was one of several considered by a team of specialists from the Memphis, Vicksburg and New Orleans Districts. Alternative plans that were considered but rejected included a no-action plan, a nonstructural plan and two structural plans.

The no-action alternative avoided negative environmental impacts, but did not provide protection of the human environment and area's economy. The nonstructural plan would have involved purchase of flowage easements on over 16 million acres in lieu of levee enlargement and seepage control measures. Although the nonstructural plan would have been environmentally sound, costs would have been prohibitive.

One construction plan called for the use of borrow material on the land side of levees for construction, but it was eliminated because of higher costs and adverse environmental considerations. The other construction plan used traditional construction techniques but was not recommended because of the greater magnitude of adverse environmental impacts. The Record of Decision was signed on Monday, October 5, 1998.

Mississippi River and Tributaries Project, Mississippi River Mainline Levee Enlargement & Berm Construction Project, Supplemental Environmental Impact Statement Newsletter, October 1998.