Springs, Springsheds, and Karst

Springs

A spring is a focused, natural discharge where water emerges from the ground.

Springs are important water sources for coldwater streams (trout streams), cool and warm water streams, and lakes and ponds. They also sustain unique ecological habitats and have aesthetic and historical value that creates a special "sense of place" for local residents and visitors.

Minnesota Spring Inventory

The Minnesota Spring Inventory (MSI) provides a statewide spatial database with information from historical records, field analysis, and citizen input. We need the help of citizens to expand on our current knowledge. You can report spring locations from your mobile device or home computer with the MSI Reporting App.

 

Springsheds

Springsheds are areas within groundwater and surface water basins that contribute discharge to springs.

Understanding the extent of springsheds is important for the protection of the groundwater supply to springs. This involves determining the size of the land area that contributes to spring discharge, which can encompass both a surface watershed and an underlying groundwatershed. The boundaries of groundwater springsheds do not necessarily correspond to those on the land surface and are dynamic in their areal extent, changing as groundwater levels rise and fall.

Dye Tracing

Groundwater tracing, most often using fluorescent dye, is used to track groundwater flow and delineate springsheds. The Minnesota Groundwater Tracing Database (MGTD) provides access to dye trace reports, related publications, GIS files, and an interactive web map application.

 

Karst

Karst is a terrain with distinctive landforms and hydrology created primarily from the dissolution of soluble rocks. It is characterized by sinkholes, caves, springs, and underground drainage dominated by rapid conduit flow.

In karst, water dissolves fractures and joints in the bedrock forming a network of interconnected underground conduits that can carry groundwater long distances at speeds up to miles per day. Sinkholes, blind valleys, karst windows and springs are found on the land surface above underground karst systems and are thought of as surface expressions of karst or "karst topography." Karst also occurs in areas with few or none of these land surface features and therefore the absence of these features does not imply the absence of karst.

Minnesota Regions Prone to Surface Karst Feature Development: GW-01

Areas prone to the development of karst features within 50 feet of the surface. GIS data can be used alone or in conjunction with the Minnesota Karst Features Database.