St. Mary Levee District Executive Director Hilary Thibodeaux gave an overview of the district’s purpose to the St. Mary Industrial Group Monday.
The district was created to give one voice to the parish when facing flood threats. It provides service for 126 miles of levees that protect $4 billion of property within the parish. They protect 25,000 residences and 4,000 commercial properties.
The parish faces multiple flood threats from sources including the Atchafalaya River, storm surge, backwater and storm water. None was greater in recent memory than this past spring.
The district coordinated efforts in an emergency situation with the Bayou Chene barge sinking in order to protect St. Mary and several other parishes from flooding. It continues to work out “after the fact” permits as well as financing from the emergent situation.
Also, sinking the barge created political momentum for construction of a permanent structure in the bayou, Thibodeaux said.
In order to keep that momentum going, the district is working on every front from permitting, modeling and engineering so that the project is as close to being “shovel ready” as possible when funds are available.
There are four concepts currently on the drawing board for the Chene project:
—Two concrete barges that would be placed in the bayou.
—A poiree wall, which consists of inserts that can be removed or included as needed for flood protection. This option is limited in certain scenarios because it takes time to insert the wall segments. It would work well for situations like last spring, but not as well for a fast approaching hurricane.
—Sector gates are similar to the flood control structures at the locks. They work quickly but are expensive to build.
—A barge stored on the site that can be swung into place and sunk is the final option under consideration. It would be secured by permanent gates and sunk over a period of hours as it is flooded with water. It would protect up to +18 feet but is time-consuming to put into place and remove.
Work is ongoing to have St. Mary Parish’s master plan included in the state’s comprehensive plan. Thibodeaux announced Monday that the Coastal Protection and Restoration Authority has requested information from the district to include the Chene project in the state master plan.
To fund its many projects, the district must pull from a variety of sources. Thibodeaux said they include local taxes, cost shares with surrounding parishes, state capital outlay, Outercontinental Shelf funds, Water Resource Development Act funds, FEMA hazard mitigation grants, BP natural resource damage assessments and BP penalty funds.