Sand Creek Watershed TMDL & Impaired Waters Investigation

Sand Creek Watershed is located in Scott, Rice, and Le Sueur Counties. A watershed is an area of land where water collects in the same streams or lakes; essentially it is a big bowl. The below documents make up a comprehensive study of the water quality in the Sand Creek Watershed. The study included two parts. The first was a study of Sand Creek, which diagnosed the problems within the watershed (Volume 1) and investigated different solutions to improve water quality (Volume 2.) The second part consisted of Total Maximum Daily Load Studies (TMDLs) for two lakes in the watershed - Cedar and McMahon Lakes.
Diagnostic and Feasibility Studies
Through the studies, these wide-spread issues were identified:
  • Stream channel erosion
  • Drained wetlands
  • Removal of or changes to native vegetation
  • Too many nutrients (like nitrogen and phosphorous)
These conservation practices are recommended to improve water quality:
  • Improve vegetation near waterways; restore grasslands and wetlands.
  • Expand agricultural grass buffer strips.
  • Stabilize stream channels.
For more information on targeted conservation practices per stream, please refer to the Project Reports.

Cost Sharing


Cost share opportunities are available for landowners wishing to install these and similar conservation practices. Both funding and technical assistance are available through Scott Soil and Water Conservation District (Scott SWCD). Please visit their webpage for more information about water quality improvement projects you can do in your backyard.
Cedar Lake & McMahon TMDLs
Cedar Lake and McMahon Lake are both located within Sand Creek Watershed and were targeted as priority areas for further water quality studies and treatments.

You can read through their TMDLs and Implementation Plans, which again summarize the water quality issues and solutions.

Issues Addressed


The wide-spread problems found in these studies include:
  • Too much phosphorous.
  • Non-native and invasive plants and animals have taken over valuable resources and caused problems like muddying the water.
  • The lake is very shallow.

Recommended Solutions


Below are the recommended solutions:
  • Hold carp tournaments and acquire further research to control the carp.
  • Use herbicides to control aquatic invasive plants like Curly-leaf Pondweed.
  • Use an aluminum sulfate (Alum) treatment to reduce the phosphorous. For an example of this near you, please visit Prior Lake Spring Lake Watershed District's webpage and look at the Spring Lake Alum Treatment.
  • Fund and implement other projects to control phosphorous levels.
    • Other projects that landowners can do to help include: wetland restorations, shoreline restorations, agricultural buffer strips, use zero phosphorous lawn fertilizers, install a raingarden, and many more.
As stated above, funding and technical assistance are available for landowners who wish to install water quality improvement projects. Please visit Scott SWCD’s webpage for more information.