Plaquemines Parish looks to change coastal plan

During Hurricane Katrina, what was left of Earl Armstrong Jr.’s cattle in lower Plaquemines Parish took refuge from the flood waters on a ridge of land that had been built after Hurricane Betsy in 1965, 40 years before.

But when Hurricane Gustav struck in 2008, a coastal restoration ridge in the same area that had been built just six months earlier completely washed away.

The difference was that in the 1960s, the ridge was built to an elevation of 20 feet while in the more recent example, the ridge was only 4 feet high, Plaquemines Parish officials said this week.

As Plaquemines looks to protect the parish from storm surge, parish leaders want to return to the past, presenting the idea of building more substantial ridges to the state’s coastal restoration agency at a meeting Wednesday. They hope the Coastal Protection and Restoration Authority will include this concept as part of the state’s next coastal restoration and protection master plan in 2017.

With a requested deadline of Aug. 21 approaching for local governments to submit their plans, Plaquemines isn’t the only parish hoping to tweak the overall master plan. All of the projects submitted for consideration will have to go through the same computer modeling and study to make sure they don’t conflict with the overall goals in the battle against coastal land loss, said Jerome Zeringue, the CPRA’s chairman and the governor’s chief coastal adviser.

The master plan is limited to $50 billion in projects over 50 years, and it has to keep the overall goals of providing tropical storm protection and wetland restoration in sight.

“The plan is based on what we think we can realistically build within 50 years,” Zeringue said.

However, even if a project isn’t included in the master plan, it can still be built as long as it’s consistent with the goals and intent of the plan, he said. But parishes would need to find most of the money themselves, perhaps by tapping funds received as a result of the Deepwater Horizon oil spill in 2010 or from an increase in offshore revenue sharing expected in the next few years.

For Plaquemines Parish leaders, the locally developed concept of ridges meshes with what is already in the state’s master plan, which also includes ridge construction. Officials expect the ridges they want to build, which would be constructed along existing ridges, would help cut down on storm surge.

“The barrier islands protect the marsh, and the marsh protects the levee. It’s that simple,” said P.J. Hahn, administrator of the coastal zone management program for the parish.

The parish worked with the U.S. Army Corps of Engineers to model how much storm surge reduction can be expected from the plan, and they believe the results show a reduction of up to 5 feet.

The parish then took that information to the Federal Emergency Management Agency and got a letter that said such ridges could be included in the calculation of flood risk for an area.

“We’ve now got a plan. It’s simple, it works, it’s got the Corps’ blessing and FEMA’s blessing,” Parish President Billy Nungesser said.

The current plan initially includes seven ridges along the west side of the parish. These “speed bumps” would complement smaller diversions of river water the parish also would like to see.

The state is currently planning a large diversion of Mississippi River water and sediment to be constructed in the area of Myrtle Grove. The state is doing computer modeling to see exactly how such a diversion should be built and operated and to see whether the costs would outweigh the benefits.

In the meantime, there has been controversy surrounding these large diversions, with much of the criticism coming from fishermen who worry that the diversions will destroy the fishing areas they rely on for their livelihoods.

“Our wish in Plaquemines Parish is for smaller diversions that don’t affect negatively the shrimp, oysters and the fishery,” Nungesser said. “We’ve got to protect all that.”

The state and many conservation groups counter that even though diversions may move fisheries around, they won’t destroy fisheries. They point to current diversions, like Wax Lake Outlet, where fisheries have done well over decades.

The Coastal Protection and Restoration Authority meets at 9:30 a.m. Wednesday at the LaSalle Building, 617 N. Third St., Baton Rouge.

Follow Amy Wold on Twitter, @awold10.