Dakota County will save $440,000 by making creative use of excess soil and rock from Spring Lake Park Reserve trail near Hastings.
A new trail that will take bikers and hikers to the top of Schaar’s Bluff for a sweeping vista of the Mississippi River will be started this summer in the Spring Lake Park Reserve near Hastings.
The $10.9 million, 6-mile bluff trail will nearly complete the 27-mile Mississippi River Regional Trail that Dakota County is building along the river between South St. Paul and Hastings.
The county recently used its powers of eminent domain to gain control of land for the new trail, promising it will have “unique and memorable’’ views of the river that will make it a destination draw.
The bluff segment is scheduled to open in the fall of 2015 or spring of 2016.
Construction of a final stretch of the regional trail — in Inver Grove Heights near Flint Hills Resources — is awaiting funding.
The bluff construction will be challenging. Workers will curve the trail to the top of the bluff along a 3 to 6 percent incline, making a “bench” cut along the bluff face for a 10-foot-wide paved trail. In two locations, bridges will be built to carry the trail over ravines.
The trail and the bridges will have overlook stops to take in the river view.
“This will be a significant undertaking for us simply because of the terrain we are working in,” said Taud Hoopingarner, director of operations management for Dakota County.
It’s likely that explosives will be used to cut into the limestone rock, said Chuck Howe, chief engineering geologist at the Minnesota Department of Transportation (MnDOT). “Typically, a person would blast this out, and it would be done with a careful type of blasting that we call pre-splitting.” That calls for a row of parallel holes to be drilled for sticks of explosives. When the explosives are set, the rock face is blasted away all at once, Howe said.
The cut will extend into the side of the bluff to make room for the trail and a parallel catch area deep enough to catch 90 percent of any rock that falls in the future, keeping it off the trail.
The project will create 196,000 cubic yards of leftover dirt and rock, county Parks Director Steve Sullivan said in a recent briefing to the County Board.
For savings of about $440,000, the county plans to make creative use of the excess soil in the park and sell the rock rather than pay someone to haul it away.
Rock cut from the bluff will be crushed for use in the base of the paved trail. The rest will be crushed and stored on a 6-acre area near the park entrance now used for flying model airplanes. The spot will be fenced and closed for two to three years to allow the contractor to sell the rock, Sullivan said.
The excess dirt will be formed into hills on the east end of the park in what is now 88 acres of pasture that will be restored as prairie.
The hills will be 5 feet high and are meant to hide two houses from the trail and vice versa, Sullivan said. Clumps of oak trees will surround the hills.
Dakota County received $198,000 in Legacy fund money from the Department of Natural Resources for the prairie restoration. Minnesota Legacy funds were created by a constitutional amendment approved by Minnesota voters in part to protect the state’s natural resources.
The prairie restoration is scheduled to begin with the trail construction and be finished next year.