Property owners along the Ohio River near Olmsted, Ill., and the Corps of Engineers both agree riverbank erosion is occurring, but they disagree as to its cause.
Sandra Thornton, an Air Force veteran who has rallied her neighbors and begun a letter-writing campaign to the president, members of Congress and the media, among others, is adamant that the replacement of the former Locks and Dams 52 and 53 with the Olmsted Locks and Dam has sped up the erosion, along with the placement of four barge mooring cells and a relocated boat ramp moved due to the dam’s construction. She also believes the propulsion of passing barges has had an effect.
Col. Eric Crispino, commander of the Louisville Engineer District, and his team say high water in 2018 and 2019 is the cause and that it was coincidental to the dam’s opening, which took place September 6, 2018, according to a Corps of Engineers fact sheet on the dam.
Thornton bought her property near Ohio River Mile 966, just over 1 mile downstream of the dam, in April 2017.
“I used to have a gradual slope down to the water,” she said. “The entire slope is down now.”
It got much worse around the time the dam opened, she said. She thinks it is because the dam is forcing the water to move faster.
“The water has more than doubled in flow, and it’s directed to the Illinois riverbank,” she said.
Although she has spent $7,000 in purchasing riprap stone to try to halt the erosion’s progress, she said that has been unsuccessful, so she began speaking to others also experiencing problems.
That has included leaders of the village of Olmsted. Mayor Curtis Marshall did not respond to requests for comment for this article but told local television station WPSD of his concerns regarding Mill Road, where an embankment has subsided, leaving the road on the side of a cliff adjacent to the river.
“There’s a big safety issue,” he said. “Kids on four-wheelers, trucks, cars going down through there, and there’s a good chance they could fall off into the river.”
Thornton said she knows of four farmers who access their fields via Mill Road. One told her he no longer feels comfortable driving heavy farm equipment down the street for fear it could cause a landslide, so he no longer farms the acreage.
Thornton’s neighbor, Larry Heuerman, bought his property along the 13 years ago. He has similar complaints and also believes the erosion is due to the dam’s opening.
“It’s washing and eating my banks out pretty fast, and I can’t get anything done,” he said.
He said he has lost about 5 feet of land to the river, including some white oak trees that fell when the bank collapsed.
“It wasn’t eroding until they opened the dam,” he said, later adding, “When they let water out of that dam it shoots straight to my place and Sandra’s.”
Heuerman also said erosion is cutting away the soil beneath the pavement of Olmsted’s new boat ramp, accessed via Mill Road. The Corps of Engineers built the ramp downriver from the former ramp, relocating it because the old ramp was in the way of the dam’s construction.
Pulaski County commissioners wrote a letter to the Corps at Thornton’s urging in August. It says, in part, “With the rapid water velocity, increased levels of water flowing, significant amounts of ground from the shoreline have already disappeared, causing multiple landslides. Our county has been left with a potentially life-threatening situation.”
The letter asks the Corps to add riprap to the riverbanks in an attempt to stop or slow the erosion, noting that riprap to aid in riverbank stabilization was included in the 1985 plan Congress approved for the dam’s construction, but later removed.
Rex Wilburn, chairman of the three-person board of commissioners, did not return messages seeking comment for this article.
Corps Of Engineers Response
A team of Louisville District representatives met with Thornton and others in June 2020 to see the erosion on Thornton’s property and along Mill Road for himself. In a letter Crispino wrote to Thornton and copied to the village of Olmsted in January, he said the Corps has no indication that the dam has caused or sped up the erosion in any way.
“The Illinois riverbank in the vicinity of Olmsted has experienced soil and slope instability predating construction of the Olmsted project,” Crispino said in the letter. “This instability has been attributed primarily to the natural fluctuations in the river levels, combined with the erosion-prone soil types in this area.”
He added that hydrographic surveys performed annually between 1993 and 2018 encompassing the area of concern Thornton identified “show that the erosion and deposition patterns along the downstream Illinois bank around River Mile 966 remain consistent, and the bank in this area has been relatively stable during construction of the lock and dam. It is not evident from these surveys that any deep scouring has occurred that would be a cause of bank erosion near the area of concern. This conclusion was also reflected in additional hydrodynamic modeling conducted by the Corps’ Engineering Research and Design Center in 2015. Furthermore, as the area of concern is located downstream of the new facilities, it would not be affected by the operation of the dam at low flow periods to maintain critical water elevations upstream of the dam to allow for safe navigation.”
Olmsted Locks and Dam consists of two, 1,200-foot lock chambers adjacent to the Illinois bank and a dam with five tainter gates, 1,400-feet of boat-operated wickets that are raised and lowered as needed and a fixed weir. Even if the dam had somehow sped up erosion, Crispino said it would be unlikely for it to have done so in 2018 and 2019 because the dam’s wickets didn’t have to be raised, pooling the water behind it, from early September 2018 to mid-July 2019. High water made it possible for navigation with them lowered and the river flowing freely.
The four mooring cells—two upstream and two downstream of the dam—are unlikely to have affected the erosion since they were put in place in 2002, he said. The Corps is evaluating how industry operates in the area, Crispino said, but has no indication that the propulsion of passing tows is causing any problems, either.
Crispino also clarifies in the letter to Thornton that after consulting a preliminary design drawing it is clear the riprap originally recommended to be placed along the Illinois bank in a feasibility study for constructing the dam was never intended to reach past the lock approach walls both upstream and downstream.
“No riprap was ever proposed to be placed beyond these limits,” he wrote. “The area of concern we viewed during our meeting with you is located approximately 8,700 feet downstream from the dam, well beyond these limits.”
Instead of preventing erosion near the lock approach walls using riprap, the Corps excavated soil and rock from a naturally occurring landslide where the locks were to be built and combined it with a toe berm to protect the shoreline as a more economic solution, said Steven Hite, chief in the Corps’ Geotechnical Design Section, part of its Engineering Division.
Crispino explained this in the letter, adding, “The Corps’ analysis determined that this method would provide effective stabilization at the project site and would not adversely affect the overall stability of the Illinois bank.”
Additionally, in looking at the erosion along Mill Road, Crispino wrote it appears to be “the natural product of the soil properties in the area and the regular and highly variable flooding that has historically occurred and will continue to occur in this area, which causes significant exchange of flow between the river and groundwater at all levels, resulting in erosion of sediment during lower river elevations as the groundwater returns flow back to the river. This process may have been accelerated in recent years by the high precipitation levels that have led to higher-than-average water elevations in the area, since sustained high water levels followed by a drop in the river can increase the bank loss; however, these are natural occurrences on the Ohio River and area not caused by the Olmsted Locks and Dam project.”
Ken Lamkin, a Louisville Engineer District hydraulic engineer, explained the Corps studies further.
“Prior to the construction of Olmsted and during construction a number of both physical and numerical modeling efforts were done to analyze the effects of the new construction in the general area around Olmsted for a number of different purposes,” he said.
Those purposes included determining any impacts to navigation as well as issues related to sediment movement, including deposition and scour, primarily for the purposes of maintaining the navigation channel.
“The model has limits,” he acknowledged, but added, “We did not see anything during any of those modeling efforts that would give us any sort of pause or concern that erosion was going to be accelerated based upon the modeling that we did.”
Since the Corps was unaware of Thornton’s complaint until last year, he said, no studies have taken place since then that would indicate the dam is having any kind of effect on erosion.
Hite said studies have also taken place elsewhere on the Ohio River and its tributaries over the past decades to see if locks and dams were having any impact on streambank erosion.
“The general conclusion was made over the years that, no, the operation of our structures has not caused streambank erosion,” he said. “It continues to be predominantly affected by natural conditions.”
Resolving The Issue
Corps officials had a teleconference with Marshall, the Olmsted mayor, along with Congressional staff members April 13.
Crispino said the Corps takes its relationship with the village of Olmsted very seriously, as it does the relationships with all the communities where it has projects.
“We have partnered with the communities where we have those projects,” he said. “In many instances our employees live in those communities, so we take those concerns very seriously and will continue to work with them to address their needs and concerns.”
Amy Babey, chief of the Civil Works, Planning, Programs and Project Management Division, said the Corps does have the authority to pursue projects when public safety is at stake, including bank stabilization projects.
Following a site visit, of the type already completed for Mill Street in Olmsted, the Corps has to determine if there is a federal interest in pursuing a project and, if so, what the least costly means of addressing it is. In some cases, she said, there isn’t a federal interest, but the Corps can help local governments look at other alternatives.
In Olmsted, Crispino said, the Corps recommended the village apply to the FEMA BRICs program for grant funding to address the problem along Mill Street. That could include erosion control or perhaps relocating the street at a lower cost. Congressional staff members on the call also offered to help connect village administrators with state resources to investigate the possibility of state grant programs as well.
Babey said village officials didn’t mention any problems at the Olmsted boat ramp, so no site visit has been conducted there.
As for the issues on Thornton’s property and that of her neighbors, the Corps considers it a private property matter.
“Because this is taking place on private property outside of our project limits, we don’t have a direct authority to address that concern and remediate that concern specifically,” Crispino said. “So, really, right now we’re committed to continue to help with information, resources and helping them make connections to the different means that may be out there that can allow them to remediate this.”
Thornton provided a letter dated April that was sent to her, signed by Dewey Rissler, project manager from the Corps’ Civil Works, Planning, Programs and Project Management Branch, giving guidance.
“It is highly recommended that you contact a professional engineer with experience in similar projects to determine an appropriate design for any repairs to the slope you wish to pursue, to increase your likelihood of a project success,” Rissler wrote.
He also cautioned her that a Department of the Army permit is required for any shoreline stabilization work that would result in the discharge of fill material below the ordinary high-water mark of the Ohio River and any adjacent wetlands, and said Louisville district regulatory division staff are available to assist her with the application permit review process, also providing a link to the online application form.
Thornton remains unsatisfied and plans to continue writing letters.
Caption for top photo: Property owners along the Ohio River in and near Olmsted, Ill., talk to investigators from the Corps of Engineers during a site visit in June 2020. (Photo courtesy of Sandra Thornton)