DNR aggregate mapping projects ongoing in Redwood, Swift, and Sibley counties.
Geologists in the Minnesota Department of Natural Resources’ Aggregate Resource Mapping Program recently completed a new resource map showing the potential for sand and gravel deposits in Kandiyohi County. Aggregate resource maps are an important tool to assist in local land use planning and identifying local resources needed to construct roads, bridges, trails and buildings.
The project’s datasets, including a map to locate sand and gravel and a countywide gravel pit survey, are publically available on the DNR’s online interactive statewide mapping website.
The sand and gravel map for Kandiyohi County is the most recent product from the DNR that provides field-researched information to help land use planners, industry, and others make informed decisions on how to maintain access to and best use these resources for local infrastructure and construction needs.
DNR geologists use geologic mapping techniques like field surveys and drilling combined with computer programs to find sand, gravel, and crushed stone resources and characterize the quality of a deposit.
Minnesota's largest sand and gravel deposits are thousands of years old
Almost all of the accessible aggregate resources in Kandiyohi were deposited more than 10,000 years ago, when meltwater streams from glacial land formations deposited sand and gravel in different areas of the state.
“It would take another glaciation to replenish that supply.” said Chad Crotty, DNR aggregate geologist who worked on the sand and gravel map for Kandiyohi County. “Not only are these resources nonrenewable, but they are also unevenly distributed across the state, leading to a lack of locally available aggregate in certain areas.”
It is important to understand where these resources are located. In an area of aggregate scarcity, planners and industry leaders can use aggregate maps to ensure that any sand and gravel deposits remain accessible and affordable for future generations of construction projects.
DNR working on multiple aggregate map projects
The Minnesota Legislature established DNR’s Aggregate Resource Mapping Program in 1984. Their goal is to complete detailed aggregate maps for every county statewide.
Today, 20 Minnesota counties have access to completed aggregate resource maps.
A three-year grant from the Minnesota Environment and Natural Resources Trust Fund, as recommended by the Legislative-Citizen Commission on Minnesota Resources, provided funding for aggregate resource mapping in Kandiyohi, Redwood, Swift, and Sibley counties.
For more information, visit the Aggregate Mapping Methodology webpage.