Coastal project aims to use river mud to build land

$750,000 in grant money builds speed bumps and new channels in the marsh to capture sediment
Updated: Sep. 4, 2020 at 10:13 PM CDT
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NEW ORLEANS, La. (WVUE) -Chris Macaluso reaches into Quarantine Bay on the east bank of Plaquemines Parish and scoops up a handful of river mud.

“Heavy mineral sediments with organics and stuff,” said Macaluso, the Center for Marine Fisheries Director for the Theodore Roosevelt Conservation Partnership.

“But it’s this that established the main headlands of Louisiana.”

While the Mississippi River has finally fallen from higher-than-normal levels of the last few years, coastal activists believe it has left behind the building blocks of a new portion of the delta.

It is taking shape in one of the few places where the river, free of levees, still connects to the marsh.

“Three years ago, we could run right through here,” said Ryan Lambert, a charter boat captain whose boat now gets caught up on sand bars in Quarantine Bay and nearby Bay Denesse.

“Now, it’s all complete land,” Lambert said.

“Every time you get a sediment bump in the river, it comes out here and hits these mudflats and hits this vegetation and builds more land,” Macaluso said.

In this case, man has given the river a little help, a $750,000 project to cut new channels into the marsh.

These crevasses feed river sediment into those areas, where sediment clings to new sandbars and vegetation.

“If I come out here and slow that water down with crevasses and terrace projects, it grows instantly,” Lambert said.

The project, paid for with grant money provided through the North American Conservation Act, also installed terraces to act as sort of speed bumps to slow the flow of river water through the marsh.

A similar effort 15 years ago has built significant land around those original terraces in Bay Denesse, Lambert said.

The newest effort, in which Lambert partnered with Ducks Unlimited and others, is designed to build about 2,800 acres.

“But it’s going to build a lot more than that because it’s already built that much and this is it’s first year that we got it complete,” Lambert said.

Not everyone is sold on the value of allowing the river run free in the marsh, including many commercial fishermen who fear fresh river water will damage existing fisheries.

Lambert, a firm disciple of diversions, points out this smaller project comes at a bargain price by coastal restoration standards.

“$600,000 for 2,500 to 4000 acres, that’s pennies compared to what we’re doing,” Lambert said.

While the grant money totaled $1,000,000, Lambert said the project came in a few hundred thousand dollars under budget.

Hurricanes Marco and Laura may provide a temporary setback, with a one-two punch that washed away aquatic vegetation which had been accumulating on the service.

Activists say, in the longer term, other projects over the last 15 years have converted open bays to marsh.

“It’s just incredible,” Lambert said. “It’s a miracle of nature to watch it work.”

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