LSU researcher believes simply filling in oil field canals reverses some coastal land loss

Dr. R. Eugene Turner points to examples where land was restored

LSU researcher believes simply filling in oil field canals reverses some coastal land loss

NEW ORLEANS (WVUE) - R. Eugene Turner believes the solution to at least some of Louisiana’s coastal land loss is staring officials in the face: backfill many of the oil field canals that dissect the coastal marshes.

To get equipment in place and tap into Louisiana’s riches, the industry carved 35,000 oil canals through the marsh beginning nearly a century ago.

“It’s enough to go around the earth three-quarters of the distance around the earth at the equator,” said Turner, a professor in the LSU College of Coast and Environment.

In the vast majority of cases, the canals leading to abandoned and capped wells were never plugged or backfilled.

"It really interferes with the water movements in and out of the marsh,” Turner said.

A graphic depicts oil and gas drilling permits dating back to the 1930s.
A graphic depicts oil and gas drilling permits dating back to the 1930s. (Source: R. Eugene Turner)

The issue is not so much the canal itself as the canal banks, which block the inches of water flow that move over and through the marsh. The water, driven by tides, must find a way around those canals, which leads to the marsh alternately flooding, then going through dry periods.

“Below ground, it’s compressing the soil," Turner said. "So, the water doesn’t go below ground like it used to either.”

Like a sponge compressing, the spill banks press down on parts of the marsh, blocking the water flow below the surface.

Turner and University of Central Florida coastal ecologist Giovanna McClenachan studied some exceptions in 33 canals that have been filled in over the years.

“Some of them have worked. I mean, they clearly have worked," said Turner, noting that the canals over a period of years filled in.

The mud is not enough to fill the canal, and Turner cautions it will take time, maybe a couple decades, for land to naturally build back.

Two images below show a before and after look at one of the canals Turner and McClenachan studied.

An oil field canal before backfilling
An oil field canal before backfilling (Source: R. Eugene Turner)
Land accretion around an oil field canal that has been backfilled
Land accretion around an oil field canal that has been backfilled (Source: R. Eugene Turner)

By coastal restoration standards, Turner argues simply backfilling the canals, dragging the spoil backs down to the height of the marsh, would be cheaper.

“You could do it for $330 million,” Turner said. "That’s pretty small compared to the amount of money that people have gotten out of these wetlands.”

In contrast, the state spent more than $200 million building one 13-mile beach and wetland project west of Grand Isle.

Turner’s idea amounts to less than one percent of the state’s 50-year master plan for restoring the coast.

“Backfilling of canals is certainly a legitimate form of restoration,” said Bren Haase, executive director the Louisiana Coastal Protection and Restoration Authority.

Haase noted a project in the Barataria National Park and Preserve on the West Bank involves dragging down 16 miles of canal banks, paid for with settlement money from Transocean, the rig owner involved in the 2010 Gulf oil spill.

While the state is open to looking at similar projects, Haase argues that canal projects involve challenges such as finding and dealing with land owners who often enjoy the access the canals provide.

"I don’t think it’s unanimously accepted as the best thing since sliced bread, I guess,” Haase said.

Some people also consider the canal banks, which can rise to 6 or 10 feet, an artificial ridge that provides a degree of hurricane protection.

Turner points out some marshy areas near canals have disappeared entirely.

"But for the areas that have some marsh around them and have a canal around there, it’s still a good thing to do,” he said.

He stops short of attempting to answer who should pay for it, a politically-sensitive question given the lawsuits that seek to force the oil industry to pay for alleged damage to Louisiana’s coast.

Turner believes the state could start small with 100 canals or so and see what happens.

“It would’ve been a lot better in 1930 to fill them in,” he said,

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