Case Study: Glensheen Parking Lot


Glensheen Historic Estates
University of Minnesota Duluth
3300 London Road
Duluth, MN 55804 official website (opens new window)

The Issues:

  • Erosion problems along shoreline
  • Runoff from parking lot
  • Protect integrity of historical property

“Dan (Mcclelland) recognized the connection between runoff and shoreline protection, and wanted to protect the integrity of this historic property. Dan wanted to clean up the water, use native plants, and try out a new approach”
   –R.C. Boheim, South St. Louis Soil and Water Conservation District Manager

“The Project also prepares us for the future, when the rest of the parking lot is paved. This will make sure that we’re cleaning the additional water as well.”
   –Dan Mcclelland

“Native plants look good and are easy to care for”
   –Dan Mcclelland

Final Goal:

Improve water quality of runoff and reduce lakeshore bank erosion caused by parking lot runoff

Solutions:

  • Two Grass swales to slow, cool, filter, and infiltrate parking lot runoff
  • Rock check dams to further slow water and allow sediment to settle out
  • Bioretention area holds and infiltrates 1” of rain (about 90% of all rain events)
  • Native plants: deep roots help infiltrate and absorb water, hardiness means little care needed
  • Rock Chutes prevent additional shoreline erosion from runoff
    click for larger version

Grassed Swale with
rock check dams

Water flows from the parking lot into the swale, where the grass and rock check dams cools, slows and filters the water, and allows some of the water to infiltrate into the ground. Water that reaches the lower part of the swale in the photo then flows into the bioretention area for further treatment.

Bioretention area

A shallow, temporary pond where stormwater runoff from parking lots is gathered. The soil is a mix of sand, topsoil, and compost, and water infiltrates within 6 hours. The soil and plants remove most of the pollutants before they get into Lake Superior. Water from one swale and direct runoff from another portion of the parking lot is treated in the bioretention area