Anyone who calls the Atchafalaya Basin his or her home away from home knows how this fishing paradise can change from year to year.
It’s the country’s largest overflow swamp, and that means it captures spring’s annual floodwaters from three river basins, including two of North America’s major rivers, the mighty Mississippi River and the Red that meet up north of here and form the Atchafalaya River.
Those floodwaters carry loads of sediment, some of which flows south past the last inhabited locations in St. Mary Parish and is creating the nation’s only building delta.
But not all the sediment winds up in the Atchafalaya Delta. Lots of it stays in the Basin, and most times finds a place to drop in places where fishermen wish it wouldn’t — like Grand Lake.
There’s not enough room in this sports section to document the demise of Grand Lake.
Know that what you see today is about a third of what this expanse was two generations ago. Siltation is among the forces that have reduced its size.
Moves by the U.S. Army Corps of Engineers a decade ago hastened sediment deposition in the lake’s southern end, and that project was removed and the Corps replaced it with something called “a channel training blockage.”
That didn’t work: The “blockage” was breached three years ago and this year’s extended high-water period extended a sand bar from the lake’s south end farther north almost to the point of blocking access to the southwest portion of the lake.
Almost as soon as the water receded three weeks ago, fishermen complained about this new above-the-water ridge, and the state’s Atchafalaya Basin Program director Don Haydel took time to read and listen.
Haydel said the program staff traveled to the location and inspected “the land that has emerged from this year’s high water,” then filed this report:
“A breach in an Atchafalaya River Channel Training Blockage levee is allowing large amounts of sediment to enter and settle in Grand Lake. The sediment is rapidly forming a delta and filling in what was previously open water.
The filling of Grand Lake is a threat to access and aquatic habitat. This project is the number one priority in the (fiscal year) 2016-17 Annual Plan process because of the importance of preserving the remaining deep water habitat.”
Noted here is that Haydel identified Grand Lake as a “deep-water habitat,” and it’s important Grand Lake remain that way. It was one of a few areas fish survived the onslaught of hurricanes.
Haydel said the Corps plans to restore the block “in about six to nine months. After the blockage is restored, the ABP will remove the land that has built in Grand Lake, and dredge the lake in that location to the pre-breach depth.”