NEW ORLEANS TO VENICE (NOV), LOUISIANA, HURRICANE RISK REDUCTION PROJECT, INCORPORATION OF NON-FEDERAL LEVEES FROM OAKVILLE TO ST. JUDE, PLAQUEMINES PARISH, LOUISIANA. [Part 1 of 1]

• Published in: EPA number: 110181, Final EIS--216 pages, Appendices--638 pages, June 10, 2011
• Format: Report
• Language: English
• Published: 10.06.2011
• Subjects: Borrow Pits; Coastal Zones; Dikes; Dredging; Emergency Supplemental Appropriations Act of 2006, Funding; Farmlands; Flood Protection; Hurricane Readiness Plans; Hurricanes; Louisiana; Mississippi River; Rivers; Section 404(b) Statements; Water Quality; Wetlands; Wildlife Habitat

PURPOSE: The replacement or modification of 32 miles of non-federal levee (NFL) system for incorporation into the New Orleans to Venice (NOV) federal project and the construction from ground level of two miles of earthen back levees in Plaquemines Parish, Louisiana are proposed. The project area is located 15 miles south of New Orleans on the west bank of the Mississippi River between Oakville and St. Jude. Plaquemines Parish has long, narrow strips of protected land on both sides of the Mississippi River between New Orleans and the Gulf of Mexico. Hurricane and flood protection is currently provided by a system of federal levees along the river and federal and non-federal back levees which border the Gulf of Mexico's coastal wetlands and protect the land between the gulf and river from tropical storm surges. The distance between the gulf-side back levees and the river varies, but is usually less than one mile. The NFL, which is currently maintained by Plaquemines Parish, was authorized for incorporation into the NOV federal project after extensive damage during Hurricanes Katrina and Rita. Key issues identified during scoping include the level of risk reduction, levee alignment, project cost and duration, and impacts to wetlands. Four alternatives, including a No Action Alternative (Alternative A), are considered in this final EIS. Under the proposed action and selected alternative (Alternative B), existing levee sections would be raised to a two percent design elevation, or approximately a 50-year level of risk reduction (LORR), and all five sections of the NFL would be incorporated into the federal hurricane and storm protection system by employing alignment alternatives which closely follow the existing levee alignment. The existing levee elevation would increase by three to four feet, National Geodetic Vertical Datum (NVGD), in the northern portion of the project area and by eight feet, NVGD, in the southern portion. Alternative B2, which is the locally preferred alternative, would be identical to the proposed action except that higher levee grades would be employed in Section 1. Under Alternative C, the levees in Sections 1 through 3 would be raised to a two percent LORR and incorporated into the federal system; and at the end of Section 3, the levee would be designed to turn 90 degrees to the east to tie in to the existing Mississippi River levee. The estimated fully funded cost of the selected alternative, including mitigation, is $456 million. Levee replacement and modification would be conducted over a three to five year period subject to weather and funding. POSITIVE IMPACTS: Implementation would provide enhanced storm surge protection and protect evacuation routes, thus reducing risk to public safety and damage from catastrophic storm inundation. NEGATIVE IMPACTS: Use of proposed government-furnished borrow areas could impact a total of 908.6 acres of farmland. Direct impacts to 46 acres of bottomland hardwood habitat, 24.9 acres of swamp habitat, 10.4 acres of fresh marsh, 16.1 acres of brackish marsh, and 144.9 acres of wetland pasture would require mitigation. Construction activities would cause temporary disruptions to traffic and generate noise and dust. Temporarily increased sediment loads would result in minor increases in suspended solids and turbidity in local waterways. LEGAL MANDATES: Emergency Supplemental Appropriations Act of 2006 (P.L. 109-234).