Battling erosion in the Porkies
ONTONAGON — An emergency shoreline project is underway to protect the main entry road on the east end of Porcupine Mountains Wilderness Park from erosion aggravated by high Lake Superior water levels and storm damage.
The Michigan Department of Natural Resources and the Ontonagon County Road Commission have teamed up to protect Ontonagon County Road 107 to ensure continued east access to the 60,000-acre park and its signature attractions.
The DNR is not typically involved in county road projects but is in this case because of the road’s importance to the park.
“Without this main accessway, should a road wash out or undermining occur, visitors to the park’s east end may be required to take an 80-mile detour, via west end entry, or be prevented altogether from reaching numerous points of interest,” said Eric Cadeau, DNR regional field planner.
The estimated $550,000 project is focused at protecting critical roadway assets along the 107th Engineer Memorial Highway, or County Road 107, including the Union River Bridge and shoreline along the road west of the bridge.
“This shoreline protection project is an immediate-response effort intended to keep wave action and storms from further eroding or undermining the bridge or roadway that collectively serves as the eastern gateway to the park,” Cadeau said. “The DNR Parks and Recreation Division and the Ontonagon County Road Commission have also begun a public engagement and planning process, which will help us determine long-term solutions for protecting this invaluable resource.”
For now, large angular riprap stone will be placed 250 feet east and west from the concrete bridge deck at the Union River. Shoreline armoring will continue west of the bridge, protecting sections of the county road immediately vulnerable to damage in seasonal Lake Superior storm events.
The work is expected to continue through October, affecting traffic along County Road 107, from a half mile east of the Union River Bridge to a half mile west of South Boundary Road. Motorists should expect single-lane closures and one-way traffic controlled by temporary traffic signals.
“The public will be able access the beach and Lake Superior along significant lengths of the county road, but access will not be permitted within the work zone, including at beach areas,” said Mike Maloney, Ontonagon County Road Commission engineer.
Over the past several years, Lake Superior has been experiencing high water levels. In 2014, the lake level rose above the long-term annual average where it has remained. Currently, the Lake Superior water level is 2 feet above that mark. Lake Superior’s water levels are forecasted to be at, or near, record high levels through April 2020.
“In addition to the high-water levels, County Road 107 is affected by wind and waves traveling from up to 170 miles away, which increases wave energy and heightens erosive impacts on the shoreline and the undermining of the road,” Cadeau said.
Meanwhile, the DNR, road commission and the Michigan Department of Transportation have been working over the past several months to develop multiple options for a long-term solution, identify funding sources and create a planning timeline.
A report outlining long-term options and cost estimates can be found at Michigan.gov/DNRPublicInput.
Comments on the long-term options for County Road 107 may be sent through Aug. 31 to CadeauE@Michigan.gov.