Houma Navigational Canal flood gate one step closer to reality

With the final design of the interim barge floodgate at the Houma Navigation Canal being authorized last week, Terrebonne Parish residents are one step closer to having floodgate protection on what has been touted as Houma’s Achilles’ heel.

Barge gates are being built at the five major points outlined in the Morganza-to-the-Gulf Hurricane Protection System in lieu of sector gates, which are currently called for in the federally authorized system now being reviewed.

Although less expensive, barge gates require more manpower to use than sector gates, don’t operate as quickly and aren’t viewed to have the environmental benefits of sector gates. Nevertheless, the Terrebonne Levee and Conservation District (TLCD) has now authorized Shaw Coastal to complete the final barge gate designs on nearly all major waterways on the interim Morganza project.

“Sector gates are easier to operate, the problem is that they’re costing $40 or $50 million, and [barge gates] cost $10 or $15 million,” said Terrebonne Levee and Conservation District President Tony Alford. “We have to start sacrificing convenience for safety. We have to get flood protection on the ground to protect the residents as soon as we can, and these gates do that. If we have to work a little harder, so be it.”

The barge gate on the HNC faces an extra hurdle because the state is helping the levee district pay for the estimated $40 million structure.

“As the state sponsor, and since we’re providing state dollars for that, we have an agreement with the levee district to provide some oversight,” said Jerome Zeringue, deputy executive director of the Coastal Protection and Restoration Authority.

Although the Levee District has started building Morganza without direct federal involvement, they are hoping the work being paid for now will count towards their share of the federal project in the future.

The barge gate structure on the HNC will eventually be replaced by a lock complex – which includes a sector gate.

The state says it is doing its do diligence to make sure that a barge gate on the HNC will be given credit towards the federal Morganza system.

“Part of what we are doing is, we want to ensure, as best we can, that we’re meeting [Army Corps of Engineers] standards so we can apply for credit for what we do,” explained Zeringue.

Although the HNC barge gate would ultimately be replaced, it could still play a role in the lock complex currently in design. It would be built in the dry area next to the canal, and an earthen damn used to close the HNC. However, once the lock is functional, the interim structure could be welded shut to replace the earthen dam.

“I think the gates we will get credit for the earthen damn that will be placed in the channel. It has a tremendous cost and a 20-year construction period. So we could probably get credit for that,” said Reggie Dupre, executive director of the TLCD.

While the corps continues to clear up red tape, which could take decades, the barge gate on the HNC would protect residents of Terrebonne Parish from storm surges.

“Even in the best-case scenario, assuming that Congress changes the law and let’s them continue the design of the $400 million lock complex, the best case scenario is 2020 or beyond, because the last component of the lock complex to be done is closing the channel. The channel is going to be open through out all of that,” said Dupre.

The need to build a flood control structure for the HNC intensified after a recent ruling against the corps for its operation of the Mississippi River Gulf Outlet. A judge in New Orleans’ federal district court ruled that the corps was liable for flooding caused by the MRGO because they failed to properly maintain the channel. The HNC is a very similar waterway and has been known to cause flooding in Houma during hurricanes.

This has caused speculation that it could leave the parish and the corps liable for flooding caused by the HNC.

“The argument I’ve made is that it’s worth $4 million a year for a 10-year period to protect the city of Houma and the majority of the population of Terrebonne Parish from a devastating flood from the HNC during all the planning and raising money and building of the lock complex. We get to have protection 10 years earlier,” said Dupre.

The use of a barge gate on the HNC has also come under fire from environmental groups, who favor the proposed lock complex.

“I think their concern is that the barge structure is going where the lock complex is planned by the federal government. I think that they think once we get hurricane protection for the channel, all the players will lose focus on the lock complex, which has a tremendous environmental component,” said Dupre.

In spite of environmental and convenience concerns, the floodgates should provide protection from storm surges for parts of Terrebonne and Lafourche parishes. These structures will also tie into levees being built by the Levee District and eventually be an integral part of the interim Morganza system.

“It’s a big deal that these structures are going in place,” said Zeringue. “Anything that can be done to minimize or reduce the effects of storm surge or flood inundation is positive.”