Title
Dye Tracing Within the St. Lawrence Confining Unit in Southeastern Minnesota
Publisher
Proceedings of the 11th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst. © 2008 American Society of Civil Engineers. Published online: June 20, 2012
Abstract
Southeastern Minnesota’s karst lands support numerous trout streams. These trout streams are formed by springs discharging from Paleozoic bedrock. Dye tracing has been the tool of choice for mapping the springsheds (karst groundwater basins) that feed these springs. Previous work was focused on the Galena limestone karst. In order to accelerate springshed mapping, a two-year study was funded by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative- Citizen Commission on Minnesota Resources (LCCMR). Across southeastern Minnesota, numerous springs discharge from the Cambrian St. Lawrence formation. The St. Lawrence is considered to be a confining unit under the Minnesota well code. A dye trace was initiated when a stream sink was discovered in the upper St. Lawrence Formation. The sampling points included springs, stream crossings, and a municipal well that may be at risk for surface contamination. Dye was recovered at one spring in less than two weeks and at two other springs in less than three weeks. This translates into travel times of 200- 300 meters/day. The springs all discharge from the lower St. Lawrence Formation. The
St. Lawrence contains beds of dolostone; the dye trace demonstrates that there is a karst conduit flow component in this formation. This is evidence that these springs are significantly more susceptible to degradation than previously thought.
Previously Published Citation
http://dx.doi.org/10.1061/41003(327)45
Description
A single trace near the Fillmore-Winona County Border near the City of Rushford, Fillmore County, Minnesota. The trace began in Winona County and did not cross the county boundary. Primary goal of the study was to delineate the springshed feeding a cluster of trout streams. A collaborative effort between the Minnesota Department of Natural Resources and the University of Minnesota.
Funding information
Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative - Citizen Commission on Minnesota Resources (LCCMR)
Suggested Citation
Green, Jeffrey A; Luhmann, Andrew J; Peters, Andrew J; Runkel, Anthony C; Alexander Jr., E. Calvin; Alexander, Scott C.
(2008).
Dye Tracing Within the St. Lawrence Confining Unit in Southeastern Minnesota.
Proceedings of the 11th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst. © 2008 American Society of Civil Engineers. Published online: June 20, 2012.
Retrieved from the University of Minnesota Digital Conservancy,
https://hdl.handle.net/11299/185404.