Big Louisiana coastal restoration projects shore up hurricane defense

Big Louisiana coastal restoration projects continue

A dredge in the Mississippi River near Venice, La., pumps sediment from the bottom July 21. A pipeline carries the sediment to create 7 miles of new marshes and ridges, starting near Venice. (AP/Janet McConnaughey)
A dredge in the Mississippi River near Venice, La., pumps sediment from the bottom July 21. A pipeline carries the sediment to create 7 miles of new marshes and ridges, starting near Venice. (AP/Janet McConnaughey)

BELLE CHASSE, La. -- Louisiana has completed one of its biggest coastal restoration projects yet and is at work on even bigger ones.

The dredge used to suck up sediment from the Gulf of Mexico to add 1,000 acres of habitat to sites in the Terrebonne Basin is now at work in the Mississippi River, doing the same for a 1,600-acre project that's further east and named for a historic Plaquemines Parish outlet called Spanish Pass, officials said recently.

"These are key examples of our frontline defense" against hurricanes, said Bren Haase, executive director of the state Coastal Preservation and Restoration Authority.

They had been eaten away by erosion and subsidence -- and by sea level rise, which, like hurricanes, is made worse by climate change.

On July 26, the authority announced completion of another project -- the addition of about 256 acres of beach and dune and 143 acres of marsh on West Grand Terre Island.

Barrier islands and marshes slow storm surge, so the work protects people and buildings on shore while providing habitat for plants and animals.

The Spanish Pass project starts just outside the Plaquemines Parish town of Venice.

The fragility of the wetlands fringing Louisiana's coast was illustrated less than a minute by seaplane from the project's west end. In that spot, trees grow in parallel lines on relatively high ground in open water. They mark the banks of canals dredged through marshes that no longer exist.

The state's biggest restoration project so far was 1,200 acres completed in 2010 in the upper Barataria Basin, the authority's deputy director, Greg Grandy, said in an email. And work began in January on the nearly 2,800-acre Lake Borgne Marsh Creation project near Shell Beach in St. Bernard Parish.

"The more land I have between me, wherever I'm standing, and the Gulf of Mexico as a hurricane is approaching, the better I feel, the better off we are," Haase said. "Those natural barriers are very, very important."

The Terrebonne Basin project increased the size of Timbalier and Trinity-East islands and West Belle Headland as well as creating 8.6 miles of beach. It took about two years, partly because of hurricanes in 2020 and 2021.

Hurricane Zeta in 2020 and Hurricane Ida last year both crossed the work area, Haase said.

He said work to enlarge Trinity East Island was completed before Ida hit on Aug. 29, and it stood up well to the storm. However, Ida damaged incomplete work on West Belle Headland -- an area that also had been worked on in 2018 to repair damage from Hurricanes Katrina and Rita in 2005.

The dredge is now working to create 7 miles of marshes backed by ridges in an area of the state west of Venice. The ridges, high enough to be planted with trees, are designed both to protect the new marshes from erosion and to slow storm surges heading toward shore.

The project will take 10.8 million cubic yards of sediment -- enough to fill the Empire State Building nearly eight times.

Money paid by BP LLC after the 2010 oil spill is funding the current projects.

The Terrebonne Basin project cost $166 million. The Spanish Pass and West Belle Terre projects are about $100 million each; the Lake Borgne project is about $61 million.

The Barataria project, completed about a month before the spill, cost about $36 million.

  photo  The southwestern end of West Grand Terre Island in Louisiana's Barataria Bay is shown July 21. The Coastal Protection and Restoration Authority has announced the completion of $100 million worth work to restore 251 acres of beach and dune and 147 acres of back-barrier marsh on the island. (AP/Janet McConnaughey)
 
 
  photo  Bren Haase, executive director of the Louisiana Coastal Protection and Restoration Authority, talks with reporters July 21 at Southern Seaplane in Belle Chasse, La., before a seaplane tour of barrier island and marsh creation projects. (AP/Janet McConnaughey)
 
 
  photo  This photo shows Timbalier Island on July 8, 2021. It is one of two barrier islands and a headland where the Coastal Protection and Restoration Authority recently added 1,000 acres of land and 8.6 miles of beach. (AP/Coastal Protection and Restoration Authority)
 
 
  photo  This photo shows work underway on Jan. 18 to create marsh and ridges in the Spanish Pass area of Terrebonne Parish. The 1,600-acre project is the Coastal Protection and Restoration Authority's largest project so far. (AP/Coastal Protection and Restoration Authority)
 
 
  photo  Part of Venice, La., and behind it part of the area where the state Coastal Protection and Restoration Authority is building 7 miles of marshes and ridges is seen July 21. The straight line that zigzags at the right will be part of a ridge, relatively high ground where trees will be planted. (AP/Janet McConnaughey)
 
 

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