ST PETER — When the snow melts and rains come in the spring, tons of soil can be churned off of ravines and stream banks along Seven Mile Creek, located between Mankato and St. Peter.
With the recent installation of hard plastic liners in some of the steepest ravines coming into the creek inside Seven Mile Creek Park, environmentalists and county officials hope to cut the amount of sediment going into the designated trout stream, which empties into the Minnesota River.
“So much of the data is telling us that fast waters are eating away at the bluffs and blowing out the sides of these small tributaries like Seven Mile,” said Scott Sparlin, a New Ulm conservationist who’s long worked on water quality issues.
Working with the Friends of the Minnesota Valley and Nicollet County, and using state Legacy grant money, the plastic liner was installed in several channels. The SmartDitch product (SmartDitch.com) uses black plastic panels to line ditches or streams. The liner not only protects the bank by covering it, but is outfitted with deep ribs that slows the water flow as it enters the creek.
The Seven Mile project incorporated other techniques, such as installing rocks in certain areas to create pools that further slow water flow.
“It’s probably over-designed, but we wanted to see what happens and how well it works,” said Sparlin of the test project, which was installed by Ground Zero Services of Courtland.
The project can be seen by parking in the last lot at the park, walking across the bridge and taking the trail about 100 yards.
Friends of the Minnesota Valley was awarded an $80,000 grant from the state’s Legacy fund, which uses dedicated sales tax money for water quality and other projects. About $8,000 was spent on the Seven Mile Creek project.