Department of Natural Resources to conduct aggregate mapping project in Yellow Medicine County

May 1—GRANITE FALLS

— Gravel roads have been a mess throughout the region this spring due to the saturated soil and minimal frost depth.

"It was like mud was bubbling up," is how Paul Frank, of rural Wood Lake, described one road to the Yellow Medicine County Board of Commissioners on Tuesday. Frank, who also serves as a township supervisor, said he and others don't usually come to County Board meetings to complain about roads, but the conditions this year compelled him to come and ask for help.

His home address is on a gravel county road. Along with increasing the gravel being replaced on the roads, he asked the commissioners to consider purchasing crushed granite from the Martin Marietta Yellow Medicine Quarry in Granite Falls to improve the condition of the roads.

His unscheduled visit was the perfect segue for the scheduled visit that day of geologists Chad Crotty, Heather Arends and Lindsey Savage, all with the Minnesota Department of Natural Resource's aggregate resources division.

After first making its request 20 years ago, Yellow Medicine County is now scheduled to be mapped for its natural deposits of sand, gravel and crushed rock. After a long hiatus, the aggregate mapping program was resumed in 2018 thanks to funding from the Legislative-Citizen Commission on Minnesota Resources, Crotty told the commissioners.

Kandiyohi and Swift counties were among the counties where aggregate mapping was most recently completed. Twenty-four of the state's 87 counties are now mapped, according to Crotty.

While road contractors are very aware of where aggregate resources can be found, their knowledge is proprietary. The

DNR aggregate mapping project

will provide maps accessible to the public and elected officials. In some cases, landowners are not aware of the potential aggregate resources on their property, Crotty pointed out.

Americans rely on aggregate resources for everything from roads to buildings. An average of 10 tons of aggregate is used per American each year, according to the DNR geologists. About 50% of the aggregate is used for public uses, such as road construction, they explained.

The mapping project helps public officials identify aggregate resources needed for roads. Just as importantly, it provides valuable information for land use planning, and aggregate resources can be protected.

The mapping process will require field work this summer. It will largely be completed in public rights of way, and only on private lands when permission is obtained.

Dan Moravetz, Yellow Medicine County engineer, told the West Central Tribune that the mapping project should benefit the county. He said the known aggregate resources in the county are located on the two ends of the county, about 54 miles apart.

Gravel is costly to transport, adding to the costs for road work in the central portion of the county, Moravetz pointed out.

He will be exploring the possibility of increasing the use of granite fines, but noted that they are relatively expensive compared to gravel and have some drawbacks. They can be more susceptible to washboarding.

Yellow Medicine County has roughly 300 miles of gravel roads, while townships in the county manage many more miles. The engineer said the cost of gravel is but one of many factors determining how often the county can add it to its roads. The county's highway staff perform a wide range of maintenance work on roads, from blading gravel roads to taking care of the shoulders and seal coating and patching its paved roadways.

Moravetz concurs that gravel roads were a challenge this year. This year's conditions definitely stood out in comparison to recent years, he said.