Lafourche levee districts’ DFIRM appeals OK’d

The Lafourche Parish Council approved the North Lafourche and South Lafourche levee districts’ appeal of the digital flood insurance rate maps last week.

The NLLD includes all areas north of the Gulf Intracoastal Waterway, and the SLLD consists of all areas south of the waterway.

“We felt that it was important to bring up our specific issues, and keep it separate from the parish’s appeal to make our appeal be on behalf of the North Lafourche and South Lafourche levee districts,” said NLLD Director Dwayne Bourgeois.

Following the release of the DFIRMs earlier this year, local government officials held a series of public meetings to hear comments from area residents. Although the process is voluntary, the parish is required to adopt the maps to be included in the National Flood Insurance Program.

Through the NFIP, the parish receives federal grant monies through the Hazard Mitigation Grant Program and the Community Development Block Grant program.

The Federal Emergency Management Agency administers the NFIP, which designed the Flood Insurance Rate Maps to delineate flood-risk zones and serve as a key role in the defense against flood losses on a residential, parish and national level.

FEMA officials say the new maps give local lawmakers, community planners and builders the tools to make important determinations about where and how new structures and developments will be built to maximize safety.

However, many local governments see the new maps as an incorrect representation of land elevations causing several parishes, including Lafourche, to appeal the maps.

Parish President Charlotte Randolph said one of the main reasons Lafourche is appealing the maps is because FEMA does not recognize the South Lafourche ring-levee system, a structure that has protected the parish for nearly 45 years.

The Lafourche Parish Council hired Baton Rouge-based Shaw Group, Angellete-Picciola, Woods Hole Group and Drs. Joseph Suhayda and Roy Dokka to draft an appeal.

The group conducted a field study of the parish levee system. In their update to the parish, Shaw Group’s Lou Cutrera and Suhayda said, “In some instances, (DFIRMS) show levees where there aren’t any levees. In other places where they indicate levees, they’re at the wrong height. There is a substantial amount of information missing from the modeling.”

Bourgeois said the two levee districts dispute FEMA’s methodology used in its mapping process. They believe that FEMA corrupted its mapping process by removing non-certified levees before running wave analysis to produce scientifically sound DFIRM maps for Lafourche.

“We are not appealing FEMA’s mapping process because they do a very good job in detailing how they draw up the maps,” Bourgeois said. “The issue is that they have a policy that corrupts their science.

“Generally when drawing flood maps, two different models are used: a still water evaluation model and a wave runoff model,” he added. “But FEMA’s policy decision removed the non-certified levee instead of conducting a wave analysis and letting the science run it course.”

Bourgeois said by shaving the levees off before the wave analysis is complete, FEMA maps for Lafourche have areas with several variations of elevations.

“The maps don’t really look right and they can’t be right,” he said. “There are places where two people can be standing 800 feet apart from each other on perfectly level ground and there would be five different-based flood evaluations between them. That can’t be. There is something wrong with the modeling.

“FEMA is basically upfront and honest on how they develop the maps,” he added. “It’s just that we don’t exactly agree with everything that’s on the maps.”

The levee districts’ appeal was handed in with Lafourche’s Parish Government’s appeal on Sept. 30. Bourgeois said FEMA representatives will review all the appeals before making a decision.

“It could take months before a decision is rendered,” he said.