Depth to bedrock (see the figure below) is an important consideration in land use planning. It indicates areas that will support agriculture and areas that have development constraints such as rock outcroppings and septic challenges. A summary of Stearns County’s geological characteristics are summarized below.
- Areas in Stearns County with over 100 feet of soil depth to bedrock tend to support agricultural land uses.
- Areas with shallowest depth to bedrock (less than 50 feet) are in proximity to waterways and are likely locations for stone and aggregate mining (see sidebar).
- Eastern and western Stearns County are underlain with igneous and metamorphic rock.
- Central Stearns County is underlain with sedimentary rocks. The bedrock is covered by glacial material ranging from about 50 feet depth in the east to 350 feet depth in Collegeville Township to 200 feet depth in western parts of the County.
Aggregate Resources: The following resources and regulations are examples of tools used to help manage and protect Stearns County's aggregate resources. These tools, and others should be referenced when making planning decisions that impact these resources.
- Mining Standards: Stearns County's mining standards can be found in Stearns County Land Use Ordinance #439 Section 7.17
- Mining (Gravel Operations): New mining operations are required to be permitted
by the County or Township depending
on their location. There are three types of mining operations or permits (i.e., Existing, pre-ordinance mining operations (POMO), Administrative Mining Permit, and a Interim Use Permit (IUP)). - Aggregate Resource Maps: The DNR Interactive Aggregate Resource Mapping website provides information about the distribution of quality aggregate resources for local units of government, citizens, land use planners, private companies and environmental groups.
- The Stearns County Comprehensive Water Plan (2013) and the Stearns County Geologic Atlas describe in detail the geologic history of Stearns County.
