New flood maps to raise questions for parish
MORGAN CITY, La. — Getting the new Digital Flood Rate Insurance Maps from FEMA is a major ongoing process for the St. Mary Parish Levee District that could require the parish to raise the levees or require residents to pay higher flood insurance premiums.
The levee district presented a report before the Coastal Protection and Restoration Authority of Louisiana on Wednesday at its meeting in Morgan City.
The levee district recently ended the Digital Flood Rate Insurance Maps Appeal with FEMA regarding the required increase in elevation of the levees to be certified, but the revised maps are not expected to be complete until 2014 at the earliest, said levee district consulting engineer Jason Kennedy.
The preliminary DFIRM analysis was released for St. Mary Parish in 2008. The parish’s federal levees did not meet the U.S. Army Corps of Engineers standard for 1 percent storm surge protection.
The corps based its standards on theoretical data and not on actual field data of events that have occurred, Kennedy said.
The Mississippi River and tributaries levees “were built for the 1 percent river flood, and the corps has told us the river flood event does not control it anymore, that the hurricane storm surge controls it,” Kennedy said.
One percent storm surge protection means protection against a 100-year storm.
Members of the district also did not think that the Morgan City backwater levees should be included in the levee system evaluation report because those are not federal levees, Kennedy said.
The district went through a process on the backwater levees with FEMA and made a lot of progress with FEMA, Kennedy said. The corps is willing to consider removing the Morgan City backwater levees from the levee system evaluation, which will help Morgan City, but not the rest of St. Mary Parish, Kennedy said.
The corps classifies the parish’s levees as river levees, which protect against a 1-percent riverine flood but not against a 1 percent hurricane storm surge, Kennedy said.
Hurricane protection accounts for wave overtopping of the levees, he said.
Raising the levees would be a “large, costly construction project,” he said. The levee district also needs to find out whether the levees could be raised before the new flood rate insurance maps are released, he said.
If the levee district chooses not to take any action concerning raising the levees that would cause flood insurance rates to increase and cause any new structure to have to be built at “extreme elevations,” Kennedy said.
“With the implications on flood insurance and so forth, projects we may have envisioned as being needed down the road may need to be moved forward,” said St. Mary Parish Levee District Executive Director Tim Matte.
As a local governmental official, his responsibility is to see that the levees are adequate to protect the public, but also to make sure living in the parish does not become unaffordable due to potential rising flood insurance costs, Matte said.