Army Corps share early construction timeline of Lock and Dam 25 expansion
View SourceArmy Corps share early construction timeline of Lock and Dam 25 expansion
FarmWeek Now – Bloomington, IL – 6/23/22 – Timothy Eggert
A major expansion of one of the most vital — and oldest — parts of the Upper Mississippi River inland waterway system is progressing, according to officials involved with the project.
The initial construction phases of a new 1,200-foot lock chamber at Lock and Dam 25, located just north of the confluence of the Mississippi and Illinois rivers, could start in spring 2023, said Jose Lopez, project manager with the U.S. Army Corps of Engineers.
“Phase one is out for solicitation, in fact bids are due June 24, so that phase is scheduled to be awarded in September, with mobilization starting in the winter and actual work probably early spring time,” said Lopez, who detailed the project’s timeline at the Upper Mississippi, Illinois and Rivers Association’s annual meeting in Quincy.
The first phase involves crews modifying the existing river wall of the site’s original 600-foot chamber so that it can receive the new, larger 1,200-foot chamber next to it, Lopez explained.
“It’s a lot of dynamic work because it’s in the river and that sort of open river definitely comes with its challenges, but we’re excited to have that awarded in September,” Lopez said. “The rest of the project is definitely in early design stages.”
Lock and Dam 25’s facelift is finally moving forward because of $732 million available for it in the Infrastructure Investment and Jobs Act, which in total will allocate $14 billion for U.S. waterway and port projects over the next five years.
The funding was announced earlier this year and is part of a larger $1.3 billion investment the Corps received from the law and will use to update the severely aging river system. It also includes a $97.1 million fish passage at Lock and Dam 22, and $50 million in various repairs to Locks and Dams 11, 13, 14, 15, 17, 20 and 21, according to Corps plans.
At Lock and Dam 25, the new 1,200-foot lock is necessary, officials have said, because the current 600-foot chamber isn’t large enough for standard, 15-barge tows to travel through without disassembling first.
The disassembly can take two to three hours and requires a mariner to be out on a barge deck, putting their safety at risk. With the larger chamber, a barge can move through without decoupling, and passage can take less than one hour.
For Illinois farmers, that difference in time can translate to a difference in profits on corn, soybeans and other grain commodities transported along the river toward other ports, according to Illinois Farm Bureau District 9 Director Gary Speckhart, of Quincy, who farms within 10 miles of the river.
“Depending on how much traffic comes through there, the time is going to be cut significantly. It’ll be a great improvement,” Speckhart told FarmWeek.
“The integrity of the whole process is just amazing,” Speckhart added. “We’ve waited so long, talked so many years, lobbied so many years to get some money to do this and now it’s finally starting to happen. It’s pretty neat.”
Informed design, efficient construction
Once the new lock chamber is built, the old, smaller lock will remain in service for smaller, recreational vessels, Lopez said.
But before major construction can take place, the Corps needs to complete its design phase, which includes bathymetric and topographic surveys and a range of modeling, Lopez said, adding the design phase is about 35% complete.
A large part of the design, and eventually the construction, is a series of massive concrete pile foundations that will form the base of the 1,200-foot lock chamber. And there’s the upstream and downstream approach walls as well as control houses and other permanent structures.
Engineers are also investigating how best to remediate a large riverbed scour hole, leftover from a 2010 barge accident, that is in the foot path of the new lock.
“That is a big technical risk and a big cost risk for us,” Lopez said, explaining how earlier designs of the expanded lock didn’t account for that feature.
Other risks at hand for the Corps include building the lock without completely disrupting river traffic — barges will need to keep moving through the existing chamber — and higher material costs because of inflation.
“As designs change we’re constantly looking at our cost estimates to make sure we’re tracking where we need to be,” Lopez said, adding he’s confident the project will remain within the $732 million Congress budgeted for it.
Previous feasibility studies have pegged the project, from design to full completion, at 10 years. Lopez said that timeframe isn’t unrealistic.
“Definitely a large engineering feat,” Lopez said. “The team, however, is hyper-focused. We understand the urgency and this is not a time for us to go into science fair mode. This is a time to go and design the features that we need to and go execute that.”
