North River Road between 15th Street Northeast and 10th Street Northeast remains closed to through traffic.
The River’s Edge Trail also remains closed.
The road and trail were closed Sept. 23 due to sinkholes near North River Road, one between the Missouri River and the River’s Edge Trail just east of the old 9th Street bridge, the other behind the curb radius at the intersection of North River Road and 10th Street Northeast, County Public Works Director Les Payne told The Electric last month.
Portion of North River Road closed indefinitely
Jim Wingerter, Great Falls district administrator for the Montana Department of Transportation, told The Electric that his office is researching documents and agreements to determine ownership and responsibility for the storm drain.
MDT is taking the lead to expedite materials and repairs, Wingerter said, and the failed storm drain impacts MDT, the City of Great Falls and Cascade County.
They’re working on a temporary fix to prevent further erosion and the permanent design process is underway, Wingerter said.
State funding will cover initial costs and additional funding options may be pursued as the project progresses and responsibilities are determined, he said.
The storm drain pipe is located about 8 to 10 feet below the ground surface and has been corroding for a long period of time, degrading the pipe structure, causing storm water runoff to erode the surrounding soils, he said.
The erosion created a void, causing the two sinkholes, Wingerter said, and there was no indication of the drain pipe failure or the voids until the sinkholes appeared and were noticed by city staff on Sept. 23.
There’s been no damage to the road or trail at this point and both were closed as soon as the sinkholes were discovered for safety reasons.
The void under the River’s Edge Trail was filled, Wingerter said.
Steve Herrig, Great Falls Park and Recreation director, said that his department is waiting for a second pour on Nov. 1 and plan to reopen the trail to food and bike traffic early next week.
North River Road will remain closed for now, Wingerter said, as they’re not confident of existing conditions under the roadway.
