Balancing improving the roads you use and the environment

Wetland areaRoad and bridge construction projects, like most aspects of life, are a balancing act. On one hand, repairing, replacing, and building roads and bridges are essential to keeping life moving. On the other, we want to minimize impacts to our natural resources.

That balancing act can sometimes result in a revitalized wetland area for wildlife viewing, hunting, and other outdoor activities.

Why we do what we do

“Integrity without exception” is one of our core values at the Iowa DOT and we take our charge to value and protect the environment seriously. While part of the environmental protections we follow are mandated by Section 404 of the Clean Water Act, we are fortunate to have a passionate group of environmentalists working to go above and beyond the basic requirements to not only do what is necessary but do what is right to protect our environment for future generations.

Brandon Walls is a project manager in the water resources section of our Location and Environment Bureau. His job is to make sure that any impacts to waters such as wetlands, streams, and rivers, from a construction project are handled appropriately. He said, “By law, we are required to avoid and minimize impacts to water resources if we can. If that’s not possible, we will work to mitigate any impacts, often going above and beyond what is required if there is a cost-effective way to get that done”

So what does mitigation mean? Walls said, “In a nutshell, it means we can’t avoid impacts to water resources in the construction area, so we make up for the damage to the wetlands or streams in the construction area somewhere else.”

Steamboat Rock

Hoover RubyA DOT-constructed wetland mitigation site that Walls manages is located near Steamboat Rock in Hardin County. The site, called Hoover Ruby Wildlife Area, is owned by the Hardin County Conservation Board and was constructed to offset wetland impacts associated with two U.S. 69 Bridge replacement projects in Wright and Hancock counties. Walls said, “Because the impacted areas contained both emergent and forested wetlands we were responsible for re-creating those types of wetlands in this area owned by Hardin County.”

Woodland-graphicWalls said, “We also work with the Army Corps of Engineers on mitigation sites to ensure we are developing enough wetland areas of a certain quality to meet the permit requirements. This specific permit required us to build 1.76 acres of emergent wetland and 0.4 acres of forested wetland, but we thought it was necessary to go beyond those baseline requirements to provide an area that would be more useful.”


Walls noted that a successful forested wetland can be particularly challenging to reconstruct. Although the emergent wetland at Steamboat Rock is thriving, the trees originally planted in the forested wetland portion didn’t survive after the initial trees were planted. As the project manager for the site, the team and I decided to give tree planting another shot, but expand the area to one acre in an attempt to re-establish the forested wetland.

Planting Areas

To replant the forested wetland, Walls said, “We’re trying to keep as much of this work in-house as we can to keep the costs down. We worked with the State Forest Nursery to get seedlings, which cost less than $300. I asked for volunteers from our bureau to help me plant the seedlings. Nine of us planted 225 trees of four species that like to have their feet wet.”

Planting saplings
Iowa DOT planted 225 trees at the site.

In another cost-saving measure, Walls and the team recycled tree tubes used to support the young saplings and protect them from being eaten by deer. He said, “The saplings are very small and hard to see. We went out and collected protective tubes from another wetland mitigation site that had grown up enough to not need them anymore.”

Recycled tree tubes
Tree tubes were collected from another site that didn't need them anymore and reused at Hoover-Ruby to help the trees become established.

Walls will be responsible for monitoring this site for the next few years to make sure it succeeds and grows into a successful wetland area. “I have trail cameras out there and one of the coolest things I’ve seen is a pair of Sand Hill Cranes. They haven’t been spotted much in Hardin County, so seeing them use our site is exciting.”

Once the entire wetland is functioning as it should, the Hardin County Conservation Board will take over the monitoring and maintenance long-term. Walls added, “This is going to be a really nice resource for the public to hunt and view wildlife.”

Preserving the environment and providing places for recreation is just one more way the Iowa DOT is making lives better through transportation.

thank you for being so conscientious about our native habitats!

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