Army Corps of Engineers Wants to Deepen 445-Mi. Stretch of Arkansas RiverView Source
Headed down the Arkansas River, a barge locks through at the Ozark-Jetta Taylor Lock and Dam in Franklin County, Arkansas. Located at mile 308 of the river, the Ozark lock and dam is just one unit of the McClellan-Kerr Arkansas River Navigation System (USACE photo).
The Little Rock and Tulsa districts of the U.S. Army Corps of Engineers (USACE) are seeking input for a project to deepen a 445-mi. section of the Arkansas River, increasing the amount of cargo that can be shipped along the waterway.
The effort, which aims to deepen the McClellan-Kerr Arkansas River Navigation System's channel by just a quarter of its current minimum depth, has been in the works for at least two decades.
The Northwest Arkansas Democrat-Gazette reported June 12 that construction on the project is projected to begin in 2025, and noted that Eric Larrat, a biologist with the USACE's Regional Environmental Center, said his office estimates it will take about a full decade to complete.
The Corps said the project will lower transportation costs, a benefit to "producers and consumers throughout the region and nation." Currently, about $5 billion in goods are moved annually along the river system, which travels east-southeast from Tulsa, Okla., through Arkansas, to the Mississippi River.
Before that construction can start, though, the USACE needs to conduct a "supplemental environmental assessment" to examine the potential effects of the project, as well as how to mitigate any negative consequences it identifies. The analysis would follow up on a lengthy 2005 environmental impact statement, and is necessary to ensure the project complies with environmental laws.
Edmund Howe, chief of hydrology and hydraulics of the USACE's Little Rock district, said it took months just to learn what was in the 18-year-old study. Further complicating the issue, the waterway has changed in the years since the earlier analysis was first completed.
"You can't just take that book off the shelf and go build it," he told the Democrat-Gazette. "We've got to modernize it. What's different? What's changed?"
Kelly Dobroski, another biologist, and a colleague of Howe's said the assessment is also required under the National Environmental Policy Act (NEPA).
"It's really the umbrella law that guides the work that we do as the government," she explained.
The assessment helps those in charge of the project identify best practices before moving forward.
"It's basically outlining what we're anticipating those effects to be, [and showing] how we are going to mitigate for those impacts [and find] alternatives," Larrat said.
From those alternatives, the Corps will select the least damaging options and consider how those strategies might even be of some benefit to the natural world, according to the biologist. Additionally, the study will look closely at the limitations imposed by the environment and the funding.
The USACE noted that the study, which must be finished before construction on the project can begin, should be complete late this year or early in 2024. According to Larrat, though, it can be amended even after it is finished.
Earlier in June, the USACE held public workshops in Fort Smith, Little Rock and Pine Bluff, Ark., as well as in Catoosa, Okla., during which people were invited to ask representatives questions and to leave comments about the project.
While at the recent workshop at the Port of Little Rock, the third stop in the tour, Dobroski told the Democrat-Gazette that few people had attended the events. She added, though, that that was not surprising since the project was not very controversial
However, the Corps expects to get more digital comments as people have adjusted to submitting information online, according to Dobroski. Comments can be left at www.swl.usace.army.mil/Missions/Planning/MKARNS-12-foot-Channel/Comment-Card/. They are due by July 8.
Construction to Deepen, Constrict River Channel
Once construction begins, the massive Arkansas River project will involve placing rock structures, known as "weirs," into the channel, along with performing dredging operations. Disposal sites for dredge material also will be used throughout the project area, and the river locks will be strengthened to better allow for barges with a draft greater than 9 ft.
As much as 90 percent of the channel is already at 12 ft., Howe said. The hydrologist described the remaining percentage of the 445-mi. length of the system, though, as "quite a bit of material."
The USACE will start by prioritizing current "trouble areas," rather than beginning at one end of the waterway and working its way downriver, Howe told the Arkansas news source.
"If we have an area that's giving the navigation industry problems at the nine-foot depth, that's something we want to address first," he said.
Howe explained that weirs "constrict the river channel," harnessing the river's energy and concentrating its flows in "problem" areas where material often deposits, ensuring the channel stays open.
He estimated that 200 structures will either need to be modified or built to constrict the channel. Many will require raising existing structures to "contain more flow for a longer duration of time, so we have more scour potential that's coming through on the crossings," according to Howe.
Meanwhile, dredging involves removing sediment and debris from the channel to allow ships to pass and keep a consistent flow to the river.
Disposed material from the dredging effort will also be used to improve natural habitats. In the past, for instance, the Corps has built island habitats for terns, noted Dobroski.
One of the reasons the USACE believes the project will take about a decade to complete is that these structures are sometimes thousands of feet long.
"There's obviously only so many contractors out there that can do that kind of work," Howe said.
Another reason the hydrologist cited for the project's duration is that while "some measure of predictability" exists, the strategies of scientists and engineers must adapt to an ever-changing river. For example, areas that are currently causing problems for waterway navigation might not be so difficult to navigate in five years, he explained.
To meet that adaptive requirement, Howe said the Corps will lean toward "under designing" aspects of the project, rather than "over designing." Doing so allows the river to "talk back" to the engineers, who can then decide if their initial efforts were enough or if further work is necessary.
They could finish the project more quickly by dredging the entire system, but Howe described that approach as "riskier" because a sediment supply to the river would just fill it back again. Instead, the USACE must ensure the correct flows last for the right durations, all under the appropriate conditions.
Corps of Engineers Expect Many Benefits From Deeper River
The increased depth of the Arkansas River channel will allow barges to carry more cargo, reducing the number of trucks and trains needed to haul goods across the region, said James H. Woods, a USACE spokesperson. He added that congestion along these roads and railways is expected to diminish as a result.
That is because each additional foot of draft allows barges to carry another 200 tons. Once the channel has a consistent 12-ft. channel, it will be able to accommodate as much as 45 million tons.
Howe said transportation down the navigation system also is less costly than other methods.
"Folks that are [transporting] their agriculture can move more of it cheaper," he explained to the Democrat-Gazette, "and it puts more money in their pockets." Those savings, Howe noted, may be passed down to the consumer.
Moving more cargo using the navigation system, as opposed to trucks and trains, would also improve air quality, according to a USACE news release, and barges produce "far less" emissions on a ton-per-mile basis than trucks and trains.
Currently, about 10 million tons of cargo are moved along the waterway every year, according to the Corps. It estimates that tonnage to be "the equivalent of 437,287 semi-trucks, or 109,322 railcars."
Bipartisan Infrastructure Law Sparked Newest Efforts
Securing adequate funding has been a significant obstruction to the project since Congress first approved the 12-ft. navigation channel in 2003. By 2005, the USACE was poised to go ahead with the project, according to earlier Democrat-Gazette reporting.
At the time, environmental groups worried that material dredged to deepen the shipping lane would fill in the river's meandering curves and backwaters, spoiling Arkansas' treasured bass-casting spots. Budget observers believed that the financially strapped federal agency could better spend its money shoring up levees to protect people from flooding, rather than on a commercial navigation project.
But in 2012, a coalition of Fort Smith and Northwest Arkansas area business, civic, and elected leaders banded together to make another push for the project. A University of Arkansas at Little Rock economist also estimated the effort would cost more than $68 million.
Howe said the Corps had been able to make some modifications to the system over the years, though he described the progress as "limping along, mostly due to intermittent appropriations from Congress."
Then, last November, the White House announced the USACE had awarded over $200 million "to maintain and improve" the McClellan-Kerr system through the Bipartisan Infrastructure Law. That funding sparked the current push to carry out the river deepening project, Howe told the Democrat-Gazette.
In February, the Corps' Little Rock District received an added $4.1 million in the Fiscal Year 23 Work Plan, part of which could go toward deepening the channel. Of that, $3.3 million in operation and maintenance funds were to improve navigation along the river