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Posted on March 31, 2019
The state Coastal Protection and Restoration Authority will provide $80 million over the next three years to build a major barge floodgate on Bayou Chene at Amelia that is aimed at blocking backwater flooding of large parts of Morgan City and St. Mary Parish and five other parishes during high water events on the Atchafalaya River.
The funding commitment was announced by Gov. John Bel Edwards at the Port of Morgan City on Wednesday (March 27).
The money nearly covers the remaining cost of designing and building the permanent barge gate, which could be under construction by the St. Mary Levee District as soon as April 2020. The new gate will take the place of the temporary sinking of barges in the same location during high river events, which have occurred since 1973.
The levee district received approval of permits for the new structure in October, more than five years after proposing the project.
The other parishes that would see reduced flooding with the gate in place are Terrebonne, Lafourche, St. Martin, Assumption and Iberville.
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“Backwater flooding in St. Mary and neighboring parishes has increasingly been a problem over the past decade as the Mississippi River and in turn, the Atchafalaya, has reached flood stage,” said Gov. John Bel Edwards in a Wednesday (March 27) news release announcing the funding agreement. “Thanks to heroic, emergency efforts by the St. Mary Levee District, the worst was averted in both 2011 and 2016. Today, we are investing in this flood protection project to provide a permanent, long-lasting solution for the people of St. Mary’s Parish and the surrounding region.”
During high river events, such as the one occurring on the Mississippi in south Louisiana now, 30 percent of the river’s flow continues to be transferred into the Atchafalaya River system at the Old River Control Structure north of Baton Rouge. The high water in the Atchafalaya begins backing up through Bayou Chene, moving from west to east around Morgan City and then north, where it can overtop existing levees or wetland buffer areas, causing flooding.
The CPRA had been reviewing the potential for a permanent gate at the Amite location since just before a similar high-river event in 2011, and the project was included in both the 2012 and 2017 Coastal Master Plans.
Earlier this year, CPRA made $5 million available from its present budget to complete design of the project. Wednesday’s announcement calls for another $75 million to be used for construction, with the money coming from funds the state will receive from its share of oil revenue from federal waters under the federal Gulf of Mexico Energy Security Act. That law requires the state to use the money for coastal restoration or for projects that protect coastal areas from flooding.
CPRA’s proposed fiscal year 2020 annual plan, which projects how money will be spent on Master Plan projects, calls for $50 million for the lock project in 2020, $20 million in 2021 and $5 million in 2022.
“CPRA primarily looks to the GOMESA revenue stream to provide flood protection to coastal communities,” said CPRA chairman Chip Kline in the news release. “When projects like this one can reduce risk for multiple jurisdictions and parishes, we know we are making the right investment.”
The 400-foot-long barge gate will swing into place between braced steel sheet pile floodwalls. When sunk, its top will be 10 feet above sea level.
The project also calls for Avoca Road to be elevated to 8 feet, and 8-foot-high levees on both sides of the structure. A six-foot-high weir structure also will be built at the end of Tabor Canal.
Source: nola.com