Mitigation Study. Lake Pontchartrain, Louisiana, and Vicinity. Hurricane Protection Project.

Construction of the Lake Pontchartrain, Louisiana, and Vicinity Hurricane Protection Project caused habitat loss in the Pontchartrain Basin. There would be an annualized loss of 854 acres of brackishsaline marsh, 108 acres of freshintermediate marsh, 233 acres of marsh pond, and 134 acres of forested wetlands a total of 1,329 acres. There would also be a loss of 2,610 Average Annual Habitat Units AAHUs for seven wildlife species. Sixteen mitigation plans were considered. Two plans were selected for detailed study. Both plans mitigated over 80 percent of the wildlife acreage loss and over 95 precent of the AAHUs lost. Plan M protects the 6.25-mile shoreline of the Manchac Wildlife Management Area WMA with a non-continuous two-foot high rock dike. The 20-foot per year loss of shoreline would be eliminated and 1,200 average annual acres of wetlands would be preserved, compared to the without-project condition. Plan O would protect approximately 5 miles of the Manchac WMA from shoreline erosion, thus preserving 1,100 average annual acres of wetlands. Plan O has been chosen as the Tentatively Selected Plan since it more nearly achieves the planning objective of 100 mitigation of total AAHUs lost is responsive to all the project planning constraints is effective, economically efficient, and implementable of all plans is supported by State and Federal natural resource agencies and is on public land so it can be implemented in a timely manner.