NEW ORLEANS — A federal-state coastal restoration task force voted Wednesday to rescind its 2010 decision to close the West Bay diversion coastal restoration project in lower Plaquemines Parish.
The decision to keep the project running came after new information became available about the effectiveness of the diversion of freshwater and sediment from the Mississippi River in building land.
“It appears the diversion is working better than expected,” said Col. Edward Fleming, New Orleans District commander and chairman of the Coastal Wetlands Planning, Protection and Restoration Act task force. “When the task force made the decision a few years ago to close this, we didn’t have all the information we have today.”
One of the biggest reasons the task force previously decided to close the West Bay Diversion, which was never actually closed, was the cost of dredging additional sediment that collected in a nearby navigation anchorage area.
The anchorage and project area, which is south of Venice, was first dredged during construction. However, continued accumulation of sediment in the anchorage area since the construction, also known as shoaling, meant that the anchorage had to be dredged by the task force program twice, and the cost of the dredging became more than the program could bear.
However, a study from the U.S. Army Corps of Engineers’ Engineer Research and Development Center showed that only about 25 percent, give or take 15 percent, of the additional sediment that collects in the nearby navigation anchorage area could be attributed to the diversion project. The task force paid for 100 percent of the anchorage dredging operations since the project was built.
In addition to letting the West Bay diversion project remain open, the task force unanimously agreed to dredge the nearby anchorage area one more time at a cost of $15 million, with all of the material to be put into the West Bay project area.
“An additional (dredging) cycle buys us time,” said Garret Graves, chairman of the state Coastal Protection and Restoration Authority and a member of the Coastal Wetlands Planning, Protection and Restoration Act task force.
He said the state has asked the congressional delegation to specifically address the need for dredging in the anchorage area.
There’s no doubt the anchorage area needs to be dredged for the safety of navigation, Graves said, but added that coastal restoration money handled by the task force shouldn’t be used to do the work.
“It’s not legal for us to do so beyond what the study says is attributable to the project,” Graves said.
The finding in the corps study is similar to a study the state offered the task force in 2009 that stated shoaling in the anchorage area was occurring even before the West Bay project was built in 2003.
“The diversion is working. We’re sending the wrong message in closing something that is working,” Graves said before the vote.
However, he said, the discussion in the future will be whether West Bay is the best location to use the limited resources of Mississippi River water and sediment. The state and federal partners are considering a number of possible diversions along the Mississippi River for coastal restoration purposes.
There are ways to make the river more stable for navigation while also meeting coastal restoration goals, he said.
Although the shoaling in the anchorage area after this next dredging cycle is a concern, Sean Duffy, executive director of the Big River Coalition, said the navigation industry wants to work to find a solution that helps both ship traffic and the coast.
“We understand this is a complicated situation,” he said. “I’m concerned because it’s (the dredging) a temporary measure, but we have three years to work it out.”
Coastal nonprofit groups and Plaquemines Parish officials applauded the decision by the task force to keep the project open.
“I want to thank you guys for hopefully making this decision,” P.J. Hahn, director of coastal zone management with Plaquemines Parish, said before the vote.
After Hurricane Isaac damaged many of the other coastal restoration projects in the parish, Hahn said, the West Bay diversion came through the storm well.
“We ask you, we beg you, to keep this diversion open,” he said.