Photo By Jordan Raiff | The initial outer wall of a cofferbox is constructed and installed on the Mississippi...... read more read more
As the Mississippi River winds from Minnesota to the Gulf of America, it undergoes significant transformations. Boulders, sediment, and changing currents made the river challenging to navigate for early mariners. Thanks to the 29 locks and dams between Minnesota and Missouri, the most treacherous sections of the river are now far more navigable for boats of all kinds.
But for fish, things have become a bit more complicated.
The U.S. Army Corps of Engineers’ Navigation and Ecosystem Sustainability Program (NESP) aims to integrate navigation improvements and ecosystem restoration efforts to enhance the river system and its many uses. The Lock and Dam 22 Fish Passage Improvement Project is one of the many projects supporting this cause.
According to Project Manager, Alaina Pfenning-Butterworth, the objective of this project is to restore upstream connectivity for a wide range of migratory warmwater fish species through the construction of a fish passage structure. The project will increase access to upstream habitats and improve the size and distribution of native migratory fish populations.
“By restoring these populations, NESP furthers its commitment to improving fish habitats in the Upper Mississippi River, starting with LD22,” said Pfenning-Butterworth.
Tara Taets, USACE technical lead, emphasized that this is no small project.
“The ladder extends 600 feet off the spillway,” she said. “It’s about 200 feet wide, and the entire ladder has a C-shaped curve. The entrance was very important because if it was in the wrong place, fish might not be able to find it. Multiple studies on our native fish species and their movement were incorporated into the models. We found that fish would congregate just to the side of where the water was most turbulent.”
Located just south of Hannibal, Missouri, Lock and Dam 22 is well known to boaters and tourists. Across the river on the Illinois side where the spillway is normally accessible to the public, the project staging area sits just outside Park-N-Fish Recreation Area, which has been temporarily closed to the public during construction.
According to Ty Jones, a contracting officer representative for the project, “Sturgeon and other fish species migrate from north to south. They need moving water to do so, but our locks and dams have disrupted that process. The water flowing out of the dam differs from the constant inflow and outflow of water at the lock, which rises and falls as water traffic moves. Fish don’t always like that and don’t always travel that way. They would get stuck.”
Jones elaborated, “This project allows fish to bypass the dam. It’s the first of its kind on the Mississippi. Similar projects have been successful out west. The design uses flowing water creatively, flowing through rocks to create divots, like the dimples on a golf ball, known as pools. In each pool, areas of calm water allow fish to rest before continuing their climb. It takes a lot of energy to move from one area to another.”
Jones also noted that this design also creates a pattern that can help deter the spread of invasive carp, which is a concern for USACE and other waterway experts trying to prevent the species from reaching the Great Lakes.
“The pattern of the weir stones was designed similar to an old water navigation chart or sine wave,” Jones said. “Between each rock, there are gaps of different sizes. Some gaps are too small for fish to pass through, while others are too big, forcing them to find an alternative path. It won’t solve the issue entirely, but it will serve as a deterrent.”
Taets emphasized that the fish passage will significantly benefit fish migration in a healthier way.
“The big picture is that we want to give our native fish a fighting chance to migrate as they originally did. Before dams, the river was open with no barriers. A fish ladder gives them a chance to move through a series of pools to rest and riffles where they can burst through rushing water. It forms a stair-step design for them to get over the spillway.”
While construction began in September 2024, initial planning for the project dates back to the early 2000s, according to Jones. This has led to the design and current construction of the fish ladder, one of four Congress approved to be installed on the Mississippi River.
Taets is optimistic about the project’s long-term benefits.
“We intend to increase native fish populations. They’ll have better opportunities for spawning, which will benefit local fishermen in the long run. Although the construction site will limit fishing, we expect the fish populations to thrive once the ladder is operational.”
In a sort of trickle-down effect, Taets said, “We don’t want all the fish that make it upstream to be caught and consumed. We want them to repopulate and continue their natural cycles. Ideally, this will first boost fish populations and then benefit local communities.”
Both Jones and Taets share a deep passion for the project. Jones’ grandfather worked on the initial planning, and Jones himself helped with some of the design work during college. Taets is impressed with the project’s longevity and academic rigor.
“They’ve been planning this for over 20 years,” she said. “Seeing it come to fruition is incredible. Many smart people have done remarkable research and modeling to support the fish and the Mississippi River system. I’ve been fortunate to work with such talented individuals. Seeing the payoff has been incredibly rewarding, especially after so many years where it wasn’t the core focus.”
| Date Taken: | 07.16.2025 |
| Date Posted: | 07.17.2025 07:01 |
| Story ID: | 542932 |
| Location: | HULL, ILLINOIS, US |
| Web Views: | 26 |
| Downloads: | 0 |
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