How high's the water? Flood maps change, property owners need to act before Aug. 5

Flood Insurance Rate Maps for Eunice have changed and if you’re unsure whether you need to have flood insurance or to update what you do have, you need to act before Aug. 5.

That date is when new floodplain maps go into effect - the first substantive change in the zones since 1980.

According to Ronnie Simpson, FEMA hazardous water mitigator for Louisiana, people who purchase or upgrade a policy prior to the Aug. 5 implementation are grandfathered at a lower rate for a few years.

Eunice Code Enforcement Officer Gary Bult, who is the city’s floodplain administrator under an ordinance adopted last Friday, said the new maps alter boundaries of floodplains in the city, signficantly expanding the number of households and businesses within them.

There are two ways to find out if your property is now within a floodplain or if the designation of the zone has changed.

Maps can be viewed at Bult’s office from 9 a.m. until noon at City Hall.

A more precise way to determine your property status is to go to lsuagcenter.com, click on flood maps, click on St. Landry Parish, then search for a specific address.

A primary reason for changes in the zones is the use of new technology.

“Mapping technology is now leaps and bounds ahead of what we were using in the past,” said Simpson, who said the new maps incorporate GPS coordinates, laser-guided topography and computerized mapping.

“We now have a more detailed; a more granular view of St. Landry Parish and where flooding might occur,” he said in a telephone interview.

The floodplain designations govern what may be done in the way of new construction or substantial improvement and construction has to be elevated to or above the base flood elevations on a particular tract.

Simpson said the maps can help residents make informed decisions about protecting their property.

The FIRM is a pictorial representation of the results of hydrologic studies and historical flood and weather experience. In these studies, engineers determine how high water might rise and how often it could reach that height.

For the FIRM, they select the water surface elevation that has a 1% chance of occurring in any year and compare it with the ground elevation. That water surface elevation is called the Base Flood level.

When the water is predicted to reach, for example, 50 feet Mean Sea Level (MSL) in a certain area and the ground in that area is lower than 50 feet MSL, then the ground would be covered by water.

The area where the ground would be covered by water in a base flood is said to be in the Special Flood Hazard Area (SFHA).

When property is determined to be in the SFHA, there is a reasonable expectation that something built on the property below the expected flood level will have a 1% or higher chance of being inundated by floodwater.

One percent is five times the “acceptable” risk of fire and accumulates to a 26% chance of flooding over the 30-year mortgage period.

That is why, for buildings in the SFHA, the federal government mandates that mortgages secured by buildings in the SFHA be protected by flood insurance on those buildings.

There is a difference between “flood compliant” and “floodplain elevation.”

Compliance is achieved when a structure is built at elevation equaling or exceeding the Base Flood Elevation, say 45 feet MSL.

But that is not sufficient to remove the structure from the regulatory floodplain and therefore, avoid the mandatory requirement to purchase flood insurance.

In order to be removed from the floodplain, the construction standard is that the “lowest adjacent grade” or LAG, must be at or above the BFE. The LAG is the lowest point on the foundation where it meets the grade, where flood waters first meet the concrete.

The comparatively small difference in construction price to reach that level removes the structure from the flood plain. Though it is still advisable, the government says, to get flood insurance, it is then not a lender requirement and is much cheaper.