Last Friday, when we arrived at the boat launch, the water level was so low that we feared the tour would have to be cancelled. Fortunately, though, the airboat managed to slip off the trailer into the water, and we glided into the wetlands of Jean Lafitte National Historic Park and Preserve – Barataria Unit. Our guide for the day, Dusty Pate, the park’s Natural Resource Program Manager, was taking us to see the canal reclamation projects that the park started last year. Along with stunning landscapes and some beautiful birds, Aaron, Matt, and I were able to see firsthand the results of successful coastal restoration efforts.
As we motored through Pipeline Canal on our way to Tar Paper Canal, Dusty stopped to point out the characteristics of most canals dredged through Louisiana’s wetlands. A canal is a man-made waterway, and they have been created for decades in Louisiana to drain water from adjacent swamps and wetlands for development, provide navigable routes for boats and ships, and to bring oil and gas pipelines and exploration equipment through the marsh. Canals stick out since they’re the only straight lines in a land of curving bayous and odd-shaped ponds and lakes.
As heavy equipment digs a watery trench through the wetlands, the soil that’s dug up, or “dredge spoil”, is simply deposited next to the canal. The mounds of dirt that then line one or both sides of the canal are called “spoil banks”.
Unfortunately, this process wreaks havoc on the wetlands in two ways. The straight water pathways allow for saltwater from the Gulf to penetrate inner marshes where it kills the plant life that holds the land together. Plus, the spoil banks act as dams that disrupt the natural flow of water leading to some areas being permanently flooded while others remain too dry. The spoil banks are also prime habitat for nasty invasive plants, like Chinese tallow, that crowd out the wetlands' natural inhabitants.
In Jean Lafitte Barataria Preserve, the National Park Service has successfully backfilled, or reclaimed, about 3 miles of these damaging canals. The reclamation process, put simply, involves knocking the spoil banks back into the canals. This immediately creates more land. More impressively, by leveling the dams and partially filling in the canals, the system becomes able to heal itself. The canals fill up with sediment, the water flows naturally, and the wetlands slowly rebuild.
After seeing the signs of success from projects started just last year, Dusty pulled some daring airboat maneuvers to get us to a pilot project that had been done in 2002. The old canal was almost unrecognizable next to the natural marsh ponds that flanked it. The marsh birds certainly didn’t seem to notice the difference.
With what the park service has done, Dusty estimates there’s a total of around 15 miles of reclaimed canals in all of coastal Louisiana. That’s 15 reclaimed miles versus almost 10,000 miles of canals. We’ve got a long way to go.
Canal reclamation isn’t a silver bullet to cure our coastal wetlands crisis in Louisiana, but it is definitely a good tool . We commend the National Park Service for providing a model, and we’d like to see a lot more of these efforts throughout our coastal wetlands.
