La. parish aims to save itself by building land

BELLE CHASSE, La. (AP) - To save Plaquemines Parish from disappearing into the Gulf of Mexico, leaders in this sparsely-populated citrus and ranch country south of New Orleans want fight hurricanes by building new marsh land and forested ridges. Officials want to use Mississippi River sediment and pump it into the open water surrounding their towns and businesses.

The Plaquemines Parish Council voted 9-0 on Thursday to approve a bond issue valued between $50 million to $65 million so the parish can hire contractors to pump sediment to buffer Plaquemine's 23,000 people against hurricane waves.

"We can't wait," said Parish President Billy Nungesser. "We decided to go it alone. It's an emergency."

Plaquemines is a 70-mile-long strip of land that hugs the Mississippi River.

The plan is to lease an electric-powered dredge designed specifically for Plaquemines so it can take coarse sediment lying 90 feet deep in the Mississippi's channel and pump it through pipelines into open water just outside levees. Once ridges are built, the parish wants to plant trees on them to slow down hurricane surge.

The parish is working with federal and state agencies on getting permits for the first ridge, which they want built between Boothville and Venice, two towns at the end of La. Highway 23 not far from the mouth of the Mississippi.

Once berms are in place, Nungesser said Army Corps of Engineers modeling has shown storm surge would be reduced by 5 feet.

The bonds would be backed by a steady stream of offshore oil and gas revenues the parish expects to get starting in 2017 and from other sources, such as money BP PLC is expected to pay for damage caused by its 2010 oil spill which hit Plaquemines hard. Plaquemines expects to receive millions of dollars in compensation from BP.

There are still many hurdles - including concerns that the work will harm wetlands by creating what in effect would be levee-like structures where there are currently bays, marshes and other natural features.

"It's totally well-intentioned, but we have to make sure that we don't get in the way of natural processes that desperately need to be re-established," said Aaron Viles of the Gulf Restoration Network, a New Orleans environmental group that monitors coastal restoration plans.

The parish still does not have the federal permits from the Army Corps and other agencies. Also, the Plaquemines plan may be at odds with a new 50-year, $50 billion state master plan designed to coordinate efforts to restore coastal Louisiana, where about 1,900 square miles of land have been lost since the 1930s.

Regardless, Plaquemines officials say their land is too at risk.

Over the past five decades, Plaquemines has become increasingly exposed to the Gulf's hurricanes because it has lost more than 250 square miles of marsh and wetlands. It's under assault from sea-level rise, subsidence, oil and gas development, hurricanes and salt water intrusion.

Katrina devastated the parish, too. The catastrophic storm made landfall in the parish at Buras and most of Plaquemines south of Belle Chasse saw flooding that washed away entire towns. Belle Chasse, the seat of the parish government, lies behind federal levee protection but the rest of the parish's levee protection falls below federal standards.

Nungesser said building the existing levees higher is not much of an option because that would mean taking away what little land people and businesses have in Plaquemines.

Mining the river of sediment is seen as a must.

"It's more necessary than it is innovative," said Mark Davis, the director of Tulane University's Institute on Water Resources Law and Policy. "It's the latest chapter in the same book."

Louisiana has experimented with river sediment before as a land-building tool. One well-known example is a 1995 marsh creation project at the LaBranche wetlands near New Orleans where some 300 acres were constructed in three months with sediment taken from the Bonnet Carre floodway.

Although the project was successful, state and federal delta managers since then have moved in other directions and stayed away from using river sediment as a land-building tool, said Joseph Suhayda, a longtime coastal oceanographer and consultant who helped develop Plaquemines' plan. He said in the past 25 years, delta engineers have focused more on rebuilding the coast with big river diversions designed to restore ecological balance and flush much-needed sediment into starved marshes.

"There is no doubt that dredging makes land," Suhayda said. "The drawback over the years has been the cost."

Plaquemines officials think they can cut those costs in half or more by developing a specialized dredge. Typical dredges in use are run by fuel rather than electricity, are equipped to house work crews and are not designed to grab material deep down in a river, all of which makes them more costly than what Plaquemines is proposing, Suhayda said.

Nungesser said plans to build up land with river diversions wouldn't do enough to help Plaquemines quickly.

"To think you're going to open up a diversion to combat the Gulf of Mexico is ludicrous," he said. "I want a dredge in that river by the end of next year."

(Copyright 2012 by The Associated Press. All Rights Reserved.)