Bayou Chene Flood Protection Structure

Location
St. Mary and Terrebonne Parishes, Louisiana, south of Avoca Island
Latitude 29°37’20.98”N Longitude 91°5’36.31”W

Scope of Work
In May of 2011, the St. Mary Levee District (SMLD) was faced with unprecedented high water elevation predictions threatening St. Mary, Terrebonne, Lafourche, St. Martin, Assumption and Iberville Parishes. SMLD constructed a temporary flood protection structure consisting of a barge floodgate, sheetpile floodwalls, rip rap, and hesco baskets to prevent the areas from flooding. The structure withheld an additional 3’ of water from the parishes mentioned above.

With the success of the temporary 2011 project, SMLD procured and contracted with APTIM in 2012 to design a permanent structure in Bayou Chene south of Amelia, Louisiana. The project is currently being designed for backwater flooding with the following features:
• Steel receiving structure +8.0’ and flood gate, +10.0’, 400’ opening
• Braced steel sheet pile floodwalls to elevation +8.0’
• Elevate the existing Avoca Road to elevation +8.0’
• An earthen levee from Avoca Road to the Structure along the existing borrow canal to elevation +8.0’
• An earthen levee with geotextile fabric from the south side of the closure structure to Tabor Canal to elevation +8.0’
• Earthen levees along Tabor Canal utilizing the existing berm and geotextile fabric to elevation +8.0’
• A weir structure at the end of Tabor Canal to an elevation of +6.0’

The design of the permanent structure is in the permitting phase.

In 2016, another high water event in the Atchafalaya River threatened the surrounding 5 parish area. APTIM was contracted to design an emergency structure to prevent backwater flooding. The structure was designed, bid, and constructed in 15 days, utilizing existing wing walls from a previous flood fight. The emergency structure was left in place until the removal was advertised in July 2016 due to a greater than 1’ water differential between the protected and unprotected sides.

Construction Cost Estimate
Permanent Structure $80,000,000
Permanent Structure Project Schedule
In February of 2019 Governor John Bell Edwards announced that The Coastal Protection and Restoration Authority (CPRA) using Gulf Of Mexico Energy Security Act (GOMESA) funds would fund the entire $80 million project that is the permanent Bayou Chene structure.  The estimated start date of the project is September of 2019.  The project has been phased out for bidding and funding purposes.  Phase 1A, Clearing and Grubbing of Tabor canal is expected to start in September of 2019.  Phase 1B, Dredging and spoil placement for new the new levee on Tabor Canal will start as soon as the 2019 emergency flood structure is removed.  Phase 2, flood wall and receiving structure along with phase 3, barge gate are expected to be completed by mid 2021.  Phase 4, earthen levee completion, is expected to be completed in the first half of 2022.  You can see the schedule below.

How and Why The Bayou Chene Project Works

Bayou Teche Flood Control Structure

This project consists of a flood control structure in Bayou Teche east of it’s intersection with the Charenton Canal.  It will consist of a levee section from the northward high ground across the old Bayou Teche through Victory Island and across to the east side of the Bayou Teche.  This project is currently under design and will begin construction in the 1st or 2nd quarter of 2019.  This project is being funded partially by a grant from the Louisiana Department of Transportation “Louisiana State Wide Flood Control Program”.  You can view a fly over of the future site in the videos section.

Northbend Phase B

The Northbend Phase B project is a USACE project.  The project is designed to tie together the west side of the Northbend project with the east side of the Wax Lake
West project.  There is a gap on the Gulf Intracoastal Water Way near Hwy 317 and the Cabot Carbon Black plant.  This is another closure of a low lying area in the system that will further complete the west end loop.

Yokely Levee Improvements

The Teche Ridge Yokely Levee is the western most part of the federal MR&T system.  Over the years this segment has settled to the extent that it was no longer useful.  Using CDBG moneys from the parish, this segment is being lifted from Yokely pump station to Industrial Road in Charenton.  It will bring the protection to 8.5′ throughout the segment.