UL model shows Fresh Water District’s plan helped lower Vermilion River in storms

The University of Louisiana at Lafayette’s Flood Center is helping local governments make decisions during storms by modeling the impact on water level as it aims to model flooding across Acadiana.

To illustrate the help modeling local conditions can offer, the center’s director, professor Emad Habib, presented a study to local parish presidents Tuesday, showing that the Teche-Vermilion Fresh Water District’s efforts to lower the Vermilion River ahead of Hurricane Barry in 2019 helped to bring water levels down by 0.14 feet at the Surrey Street bridge in Lafayette during the storm.

“In order to do the best job possible, our board discussed our procedures with the staff at the UL Flood Center to see if they could create a model to demonstrate the effects of our procedures on water levels in the Vermilion River,” TVFWD Director Donald Segrera said.

During dry weather, the district pumps fresh water from the Atchafalaya River in Krotz Springs into headwaters of the Vermilion River and the Bayou Teche to keep them from becoming stagnant.

But it turned off the pumps feeding the river and closed a downstream canal connecting the two rivers in advance of the July 2019 storm to help lower the amount of water in the Vermilion, a decision that Habib’s researched backed up.

“We found that the operational plan the district follows actually can reduce the water-surface elevation of the river,” Habib said. “However, the maximum reduction was about four-tenths of a foot, and that significant reduction was limited to the north reach of the river, north of the (Cypress Island) Swamp.”

While the impact of shutting off the freshwater pumps into the Vermilion River may not sound massive, Dredge the Vermilion leader Dave Dixon pointed out during Tuesday’s presentation that many of the homes that flooded in 2016 saw less than a foot of water inside.

“A 0.2 or 0.4 reduction in the level is something,” Dixon said. “I had some in my neighborhood that had only 3 inches, and they wouldn’t have flooded.”

While the Flood Center’s model confirms what some have long expected about the impact of turning off the freshwater pumps, the model stands to have a far greater impact locally as a guidestone for broader decision making going forward.

Acadiana Planning Commission CEO Monique Boulet, whose agency is coordinating the push to house a regional watershed flooding model at UL, told the presidents of Acadiana’s parishes Tuesday that the Flood Center’s modeling gives the region a “head start” over the other watersheds in the state who are by and large waiting for action from the state government.

“In Acadiana, we have an asset that the rest of the state doesn't have, and that is very specialized research in the (Bayou) Teche, the Vermillion and the Mermentau rivers,” Boulet said.

Full article: Daily Advertiser by Andrew Capps - https://lnkd.in/ekXSDNT5