Diversion could raise flood crest in Morgan City

Though the Atchafalaya River is projected to crest at 6.5 feet July 20, that crest could reach 7 feet if the U.S. Army Corps of Engineers approves a request to divert more water downriver, St. Mary Levee District Executive Director Tim Matte said.
At Thursday’s St. Mary Levee District Commission meeting, officials discussed the high water projected for the Atchafalaya River and the potential impacts.
The U.S. Corps of Engineers has been involved in its “phase one flood fight” for the past few months, which requires the corps to survey the rivers more often when the Mississippi reaches 11 feet in New Orleans and the Atchafalaya reaches 5 feet in Morgan City, Matte said.
On Tuesday, corps officials said the Atchafalaya River is projected to reach 6.5 feet by July 20, Matte said.
At 6.5 feet, the impact to industry would be generally minimal, but it’s possible a couple of floodgates may have to close on the river in Morgan City, he said.
However, state officials received a request from landowners near the Morganza Control Structure to divert more water downriver, he said. The request is aimed at keeping an area of land dry in order to harvest a crop, he said.
If granted, that diversion could raise the river level in Morgan City another 6 inches, bringing the crest to 7 feet.
Matte and other area leaders have explained to state officials that, at 7 feet, at least three floodgates in Morgan City and a couple in Berwick would probably have to be closed, which would probably affect some businesses, he said.
If the state grants the request, it would be unprecedented in that previous diversions of flow to the Atchafalaya have been due to requests downriver for more water to combat droughts in the Atchafalaya Basin, Matte said.
Additionally, the most the corps has ever modified the normal 70 percent-30 percent split of flow between the Mississippi and Atchafalaya at the Morganza structure is by 3 percent. The proposed increase would raise the flow to the Atchafalaya by 6 percent, he said.
Even at a 6.5 feet crest, high water could linger in the area for maybe a month or more, Matte said.
Matte believes the likelihood that the corps will grant the diversion request may be “fairly small,” and corps officials will likely make a decision this weekend, he said.
Also at Thursday’s meeting, Engineer Jeff Pena of CB&I said officials are working to revise the estimated cost of the Bayou Chene Flood Control and Diversion Project. The last estimate officials did was in 2012 when the project was estimated to cost $80 million. The updated estimate is vital to be able to know how much funding to pursue, Pena said.
The Bayou Chene project includes a permanent structure that will block Bayou Chene so that floodwaters cannot travel from Bayou Chene through Bayou Boeuf to Lake Palourde.
Matte referenced the recent BP settlement to provide Louisiana with $5.5 billion, as a result of the 2010 oil spill.
About $794 million will go into one of the “buckets” available to fund portions of the state’s master plan for coastal protection and restoration, Matte said. Of that money, $79.4 million will go into a parish matching program, which enables a parish to receive money if it puts up matching funds, Matte said.
The St. Mary Levee District may be able to use the matching program to fund some of its projects, Matte said.
St. Mary will have to compete with surrounding parishes for the funds. Terrebonne has a $465 million project and Calcasieu has a project for roughly $450 million, Matte said.
“You can see right away there’s not enough money to go around to do everybody’s project,” Matte said.
Still, the Louisiana Coastal Protection and Restoration Authority is working to identify other funding sources to pay for projects in the master plan, Matte said.
St. Mary Levee District officials have repeatedly emphasized to coastal protection leaders that the Bayou Chene project benefits five parishes, including St. Mary, lower St. Martin, Assumption, Terrebonne and Lafourche, Matte said.
St. Mary Levee District Commission President Bill Hidalgo, who’s also on the CPRA board, mentions the Bayou Chene project at every meeting in an effort to seek funds for the project, Matte said.
Funds may also come from the surrounding parishes, which will benefit from being able to close off Bayou Chene to stop floodwaters, Matte said. Terrebonne Parish has already committed to provide $500,000 toward a study on the project.
During the meeting, Blaine Crochet of Darnall, Sikes, Gardes & Frederick presented the levee district’s audit for the year ended Dec. 31, 2014. The auditor issued unmodified opinions, the most favorable opinion possible, on the district’s financial statements, Crochet said.
The only finding in the audit was a repeat finding for inadequate segregation of accounting functions due to the district’s small number of accounting personnel. The auditor said the cost of adding more accounting personnel may outweigh the benefit of achieving adequate segregation of accounting functions.
In other business, the commission:
—Approved the proposed levee alignment for Lake End Park to Justa Street portion of the Morgan City Levee Improvements Project.
—Authorized advertisement to repair levee slides on the former Atchafalaya Basin Levees, which are estimated to cost less than $40,000.
—Approved cooperative endeavor agreements with St. Mary Parish and Morgan City to provide sheet pile.
—Authorized Hidalgo to sign off on the purchase of mitigation credits.

This story was written by Zachary Fitzgerald of The Daily Review staff. Reach him at zfitzgerald@daily-review.com