WEST ALTON • Just upriver from the Melvin Price Lock and Dam, at least 1,000 acres of habitat sprout from the banks of what is essentially an artificial pool.
The occasional heron flies over the vast expanse of river grass, which would have sprouted naturally along the waterway before humans attempted to tame it. The habitat is thriving especially well this year under a practice known as “environmental pool management” that the Army Corps of Engineers has adopted and is trying to enhance.
“If we don’t do environmental pool management, then the riverbanks are pretty much bare,” said Gretchen Benjamin, associate director of water resources for the Nature Conservancy.
In the other two pools created by the locks and dams the corps’ St. Louis District operates, there are at least 2,000 more acres of river grasses and wetland-like ecosystem that have been nurtured back to life over the years.
The corps and environmental groups suspect there’s probably far more acreage they have yet to measure, the result of close collaboration that has nudged the corps to do as much as it can for wildlife in the pools without harming the barge operators who need the water at a safe depth.
Bringing back wetland ecosystems means keeping the water low enough in the lock and dam pools to let the water plants take hold. For decades, shoreline grasses and other river plants had essentially been drowned in the portions of the Mississippi River in between corps-operated locks.
The engineers had a mandate to keep the river at a certain height for navigation, and environmental concerns were not front of mind.
But about 20 years ago, the St. Louis corps began keeping the water a little lower when it could, maybe for around 30 days or so. Some of the taller, heartier river grasses began coming back.
“Now, we’re looking at if we can get it to 90 to 120 days,” said Dave Busse, the corps’ chief of engineering and construction. “Before we might have said, ‘OK, (the river grass is) five feet tall, let’s fill it back up.’”
Last year was the first time the corps really tried to keep the water levels low for an extended period, but unexpected heavy summer rain forced the corps to refill the pools to keep barges moving. This year, however, Busse said Mother Nature has cooperated exceptionally well, providing enough rain so the water levels are just right for the corps to manage the depths within the pools.
“I would put this as probably our best year ever,” Busse said.
While river grasses have been making a comeback for years, the extra time has just started to yield shorter, perennial river plants such as duck potatoes, Benjamin said. The hope is that healthier waterfowl and fish populations will follow.
“The system’s a little more degraded down here, so it might take a little longer to bring it back,” she said. “We have to reset the system first down here.”
And as the local habitat builds, it connects with a larger ecosystem up and down the Mississippi River watershed, amplifying the ecological benefits for birds, fish and other animals. The work in St. Louis could serve as an example that becomes standard procedure in other corps districts.
“You’re starting to piece together these projects and have these impacts throughout the whole system,” said Jordy Jordahl, president of America’s Watershed Initiative.
The project does mean extra work for lock and dam operators who have more to monitor to keep water levels just right, Busse said. But barge operators haven’t been affected by the lower levels.
“Navigation has never lost anything,” Busse said.
Indeed, the trade group representing barge operators expressed support for the program.
“Our members not only rely on the river for transportation, they fish, hunt, boat and enjoy the river’s recreational uses as well,” Paul Rohde, vice president of the Midwest Area for shipping trade group Waterways Council Inc., said in a statement. “It’s a multiuse resource that requires managing it in a more comprehensive and thoughtful way. The Environmental Pool Management program is a model for collaborative and innovative approaches among stakeholders.”
The collaboration on this project could result in more cooperation on other initiatives, Jordahl said, such as funding navigation infrastructure or reducing nutrient flow into the Gulf of Mexico’s dead zone.
There’s a recognition that all the river’s stakeholders — environmental and conservation groups, the barge industry, agriculture and the corps — are stronger if they work together and find areas where they can agree, he said.