The structure will protect the eastern part of St. Mary Parish along Bayou Chene and is similar to the structure being built on the Houma Navigation Canal in Terrebonne Parish, said Hilary Thibodeaux, executive director of the St. Mary Levee District.
“The design or the method has been proven in that area for structural work (in Terrebonne Parish),” Thibodeaux said. “That’s why we’re moving forward or looking at alternatives similar to what’s going on there.”
The project entails building a backwater flooding structure, and the district is looking at possibly providing storm surge protection as well, Thibodeaux said.
Pena presented a 5-percent design level for the project at Thursday’s St. Mary Levee District meeting. “We just looked at a bunch of different concepts, got it to a level where we could do a good cost estimate,” Pena said.
Thibodeaux said a 5-percent design level means Pena has done initial calculations and information. “You take that and you do some real high-level calculations to get kind of a ballpark of what it’s going to take to actually go to construction.”
The levee district is working towards completing a 30-percent design level, Thibodeaux said.
The Bayou Chene project is a group effort by the engineers at Shaw Environmental and Infrastructure Inc., T. Baker Smith LLC, and Miller Engineers & Associates, Thibodeaux said.
The group’s current recommendations for the project include building a steel receiving structure with a 250-foot opening with a swing barge gate at 10 feet above sea level, a brace sheet pile wall at 10 feet above sea level and elevating the existing Avoca Road to eight feet above sea level, Pena said.
In addition, the recommendations include building an earthen levee from Avoca Road along the existing barrow canal, building an earthen levee with geotechnical style fiber from the south side of the closure to the Tabor Canal, building earthen levees along Tabor Canal utilizing the existing berm and geotechnical style fabric and elevating the weir structure at the end of the Tabor Canal to an elevation of six feet above sea level, Pena said.
Reid Miller of Miller Engineers & Associates gave an update on the Hanson Canal and Yellow Bayou projects.
“I spoke with the permit analysts with corps (of engineers) … Right now engineering is reviewing the drawings that we put together,” Miller said.
For both the Hanson Canal and Yellow Bayou projects, regarding the levees that run from east to west and run into the levees that start going north, the U.S. Army Corps of Engineers stops working at that point, Miller said. “So we’re going to pick up those points (where the corps stops) and tie those into our structures. So we’re going to have continuous, the same elevation all the way through,” he said.
In other business,
—The commission voted to accept an amendment to the Intergovernmental Agreement with the Coastal Protection and Restoration Authority regarding the disbursement of funds for emergency response to the 2011 Flood Fight.
—Voted to approve Thibodeaux to sign a letter of request for the U.S. Army Corps of Engineers to assist in levee certification.
—Voted to adopt the 2012 amended budget.
—Voted to adopt the 2013 budget.