LAFAYETTE - A new flood map for Lafayette Parish is expected to offer a mixed bag, shrinking flood zones in some areas while making large tracts of vacant land more difficult to develop.
The final version of the Federal Emergency Management Agency flood map - the first update for the parish since 1996 - has not been released, but city-parish officials say it should be in their hands within a few weeks and could be in place before the end of the year.
The map is used to determine flood insurance rates, to set elevations for new construction in flood zones and to regulate development to reduce flooding impacts.
Based on preliminary information on the new flood zones from FEMA, some communities might see a drop in the amount of land designated as a flood zone.
“We actually have less acreage in the flood zone than before,” said Broussard Mayor Charles Langlinais. “We were quite pleased.”
He said the flood zones might be reduced even further after the completion a project to clear and enlarge a 4-mile stretch of the Cypress Bayou Coulee, one of the main drainage canals for the Broussard area.
The $5 million project is scheduled to be complete this year, said City-Parish Associate Director of Public Works Pat Logan.
“It will definitely give some drainage relief,” Logan said.
The prospects for some areas are not so favorable.
The most noticeable change with the new flood map is expected to be the amount of land that is classified as a floodway, a designation that can make future development difficult.
Floodways are generally areas along a river, coulee or other waterway.
Unlike a flood zone, where development is generally allowed if buildings are elevated, a floodway can bring strict requirements for engineering studies to ensure a new development will not worsen flooding.
Those requirements can make development nearly impossible in some areas, but other developments could move forward if developers do drainage work or other improvements to offset flooding impacts.
“It’s somewhat restrictive, but not something that can’t be done,” said Larry Broussard, an engineer with the City-Parish Public Works Department.
The preliminary FEMA flood map classifies large tracts at the Interstate 10/Louisiana Avenue interchange as a floodway for water from the Vermilion River, including the retail center anchored by Target.
That development will be grandfathered in, but the floodway classification could affect other undeveloped land in an area where Louisiana Avenue was extended in part to spur commercial growth.
The draft FEMA maps also classify as a floodway a large swath along Vermilion River running from Interstate 10 north to the parish line, as well as land along major drainage coulees in and around Scott.
Scott Mayor Purvis Morrison said the city plans to appeal some of the floodway designations.
City-Parish government has already appealed the overall map and was successful in changing FEMA’s initial flood classifications in an area along Verot School Road in the southern part of the parish.
Most other areas of the draft maps are expected to remain as proposed with minor tweaks, according to city-parish officials.
Morrison said despite the expected floodway classifications in the Scott area, the city is still ripe for new development.
“We will have a lot of prime property that is not affected in the city of Scott,” he said.
Morrison said the biggest impact is not in the city itself but in unincorporated areas of the parish where Scott might grow in the future.
City-parish planners and Scott officials are embarking on a study that could offer guidance on how to develop in the flood-prone areas along Coulee Ile des Cannes, even if the land falls under the restrictive floodway classification.
Possible strategies for development include digging ponds to absorb flood water and using the excavated dirt to raise the surrounding land above flooding heights, said Mike LeBlanc, a planner with city-parish government.
Some of the low, flood-prone land could also be used for recreation, such as sports fields or parks, LeBlanc said.
He said the project could serve as a model for developing in other flood-prone areas.