Hilary Thibodeaux of APTIM engineering firm points to a screen Thursday while discussing the temporary Bayou Chene closure during a St. Mary Levee District Commission meeting. (The Daily Review/Zachary Fitzgerald)
Focus shifts to permanent Bayou Chene fix as flood fight wanes
Though the 2019 flood fight isn’t over yet, the worst may be done. Now area officials are turning more attention to the long-term solution to prevent backwater flooding in the region.
The St. Mary Levee District Commission met Thursday at the parish courthouse.
Officials completed temporary closure of Bayou Chene in Amelia on June 4, and the barge has already held back up to 2 feet of flood waters at the peak, said Hilary Thibodeaux of the APTIM engineering firm.
Corps officials have indefinitely delayed opening the Morganza Spillway as the thresholds to operate the structure haven’t been met as previously expected. The Atchafalaya River is projected to crest at 8.1 feet Monday in Morgan City. The Atchafalaya reached near 8.8 feet just last week. At one point, forecasts showed the river could reach 10 feet in late June. Authorities still expect the river stage will linger around 8 feet for a while, though.
Regardless of whether the Corps opens Morganza, the increased frequency of high water validates the need for the permanent structure that’s planned, Thibodeaux said. Officials hope to have the permanent structure operational in two years.
At Thursday’s meeting, the levee district commission authorized Commission President Bill Hidalgo and District Executive Director Tim Matte to sign a cooperative endeavor agreement with the Louisiana Coastal Protection and Restoration Authority for construction of the permanent Bayou Chene Flood Control and Diversion Project. CPRA has committed to providing $75 million to fund the project.
On July 1, $50 million will become available for the project through the federal Gulf of Mexico Energy Security Act.
After eight years of planning for the permanent Bayou Chene structure, “we’re now on the cusp of actually going to work,” Matte said.
The initial clearing and grubbing phase for the permanent Bayou Chene project should go out for bid in July, Thibodeaux said. Dredging of Bayou Chene was originally supposed to be part of the project’s initial phase. But officials separated that segment, because the temporary structure will prevent that dredging from taking place as scheduled, he said. The board authorized the district to advertise for bids on these phases.
But the temporary structure shouldn’t delay the overall schedule for the permanent project. Officials should have plans for the floodwall and receiving structure portions of the project ready by November and advertise bids in December, Matte said.
Discussions began May 22 about the possibility of opening Morganza, which led to state and area officials to make the decision to temporarily close Bayou Chene with a 400-foot wide barge. Commitment from the CPRA to fund the roughly $7 million project was the key to convince the levee district to proceed with the project.
Design and procurement of the temporary Bayou Chene project began May 24 followed by the commencement of pile driving May 27. The barge was in place May 29, and placement of rock around the barge completed the closure June 4.
Hidalgo thanked all the St. Mary Levee District’s partners that helped quickly facilitate the temporary Bayou Chene closure.
In addition to sinking a barge in Bayou Chene to block flood waters, officials also placed limestone on the road on Avoca Island, placed sandbags along Tabor Canal and blocked pipeline canals there in Terrebonne Parish to prevent the flow from bypassing Bayou Chene. The Corps provided the limestone on Avoca, and Terrebonne Levee Conversation district did work on Tabor Canal.
A crew is still on site at the Bayou Chene structure to handle any emergencies, and the state Department of Wildlife and Fisheries is providing security at the site, Matte said. The commission also approved the district to advertise for bids to remove the temporary structure when deemed appropriate.
Authorities were able to use lessons learned from the 2011 and 2016 Bayou Chene closures to ensure the 2019 closure went as smoothly as possible. In 2011, there was no frame for a structure on site before officials decided to make closure. In 2016, officials used the materials left at the site in 2011 to expedite the closure, Thibodeaux said. The Corps opened Morganza in 2011 but not 2016.
In other business, the commission
—Authorized the form and content of an intergovernmental agreement with the district’s partners to provide funding for operation and maintenance and other costs associated with the Bayou Chene permanent project.
—Authorized the district to expropriate three parcels of land along Tabor Canal and Hidalgo to sign agreements relating to land acquisition for the permanent Bayou Chene project.
—Amended a task order with APTIM for work on the temporary Bayou Chene project.
—Declared sand hoppers as surplus property to be sold at auction.
—Adopted a sexual harassment prevention policy.
—Approved an endorsement letter regarding a Corps permit for Birla Carbon.