Three washed away pipes and an eroding hill leads to $300K reconstruction.
The riverbank on the Coon Rapids campus was reconstructed this summer after the facilities department raised concern about an unsteady hill and after three sections of pipe were washed into the river. The river reconstruction has made the campus safer and protected the riverbank from further erosion.
The bend in the river was slowly eroding the riverbank on the south side of campus, hollowing out the ground beneath the hill and making it unsafe to walk on. The pipes, which carry the water out of the building into the river, were over 30 years old and had broken down.
“Three sections of pipe had been washed into the river” Steve Knight, a civil engineer on the project said. “Historically, until a few years ago nobody ever paid any attention to what was happening with those systems.”
When fishing on the river, an employee of the facilities department noticed the erosion. Facilities suspects that flooding the last few years helped to contribute to the erosion.
“When the campus was built there really wasn’t much for environmental regulations. Now, because of the PCA [Minnesota Pollution Control Agency] requirements for storm water management, we look at those structures four times a year,” Knight Said.
“It got almost to the point where it was dangerous to walk on the top of the hill because it was undermined, so we had to have all of it replaced,” Facilities Director Kenneth Karr said. Replacing it all cost the campus over $300,000.
Another benefit to the school is that a road was built down to the river. “We put a driveway down to the river so that students could go down to the river to do science experiments,” Karr said. A conduit was placed into the ground so in the future, they can have data link, lighting and power closer to the river’s edge.
Knight explained that they engineered a new structure with different types of rock and soil to create a sturdier pipe bedding, pinning the pipes in and stabilizing the river. That section of the bank had never been stabilized before.
“It should be the final solution for at least 25 to 30 years,” said Karr.