New Alligator Bayou Floodgate nears completion, parish president says


A three-gated floodgate is close to complete on Manchac Road, said Parish President Mitchell Ourso, who said he expects to accept the project as substantially complete by early July and open by early August.

The floodgate, officially called the Alligator Bayou Floodgate, is located near the location where three parishes intersect – Iberville, Ascension and East Baton Rouge. When it is complete, Manchac Road and Bayou Paul Lane – one picks up where the other leaves off – will reopen to through traffic.

The project will cost about $2.5 million when complete, monies Ourso said will come from the federal government’s reimbursement to the parish from Hurricane Gustav.

The new floodgate will replace an antiquated single-gate floodgate built in 1950 and had the guillotine style gate had to be opened using a old school hand crank, Ourso said.

“This culvert isn’t anything but a six-inch box,” he continued, much less sophisticated than the new floodgate. Before the new floodgate is complete, the old one will be demolished.

“The new gate will have three gates and it’s all going to be automated,” Ourso said. “I’ll be able to push the buttons from here (his office in Plaquemine) to open the gates and to close them.”

The new floodgate is being constructed so that traffic on Alligator Bayou will pass over it on its way to Bluff Road, which connects to Perkins Road on the East Baton Rouge end and La. 74 on the Ascension side.

When the Great Flood of 2016 slammed south Louisiana, high water from East Baton Rouge Parish overtopped the roads between it and Iberville Parish, necessitating a number of cuts to allow the water to recede. The three road cuts were 25 to 30 feet wide and 10 to 15 feet deep.

“Our road cuts were probably made 300 or 400 yards on the other side of where the floodgates are being built,” Ourso said. “They were done because all this on the Iberville side was underwater,” referring to the area near Bayou Paul Lane, primarily the subdivision just off Bayou Paul Lane.

“When we need to let water out, we open up the new floodgate and water flows into Bayou Manchac and toward Lake Maurepas and the Gulf of Mexico,” he continued.

“We’re still at the mercy of Bayou Manchac because when the water is higher on that side, the parish can’t open their floodgate until the water recedes on the East Baton Rouge Parish side,” Ourso said.

In addition to the substantial increase in flood protection the floodgates will provide Iberville Parish residents, they will also gain a recreational area in the process.

“What’s going to happen is that this is all going to be cleared out,” Ourso said, pointing to an area on a map of the floodgate area.

The recreational area is going to include a picnic area and a boat ramp to provide access to Alligator Bayou and points beyond, he continued.