St Louis River Estuary: The stories and the science

Knowlton Creek

Although Knowlton Creek is primarily forested, the stream channel has been degraded by human activities within the watershed. The degradation moved sediment into the Area of Concern and filled in a sheltered bay behind Tallus Island. It is presumed that the degradation to the creek is being caused by the combined effects of the Spirit Mountain Ski Area, the Cloquet Water Pumping Station, Interstate I-35 and the railroad line. The watershed is not able to handle the increased amount and rate of run-off as a result of the land uses.

Restoration of 23 acres of shallow sheltered bay habitat behind Tallas Island and at the mouth of Knowlton Creek was completed in 2010 as part of mitigation for the loss of wetlands as a result of the remedy at the St. Louis River Interlake/Duluth Tar Superfund Site. Although the project removed the sediment that had been deposited by Knowlton Creek, the Minnesota Department of Natural Resources began to develop a partnership that could restore the creek channel.

The project partnership has worked to complete a plan to address a portion of the excess run-off originating from Spirit Mountain, design the restoration of the creek channel and secure the necessary implementation funding. The water control project can serve as a model for water appropriation, use and treatment for other ski hill operations. The stream restoration will serve as a local model of natural channel design to build resiliency into an urban trout stream. Funding partners include the Minnesota State Legislature, Bonding, Spirit Mountain Recreation Authority, the National Fish and Wildlife Foundation, the Minnesota Clean Water Legacy Fund, the Minnesota Outdoor Heritage Fund, the U.S. Environmental Protection Agency (through the Great Lakes Restoration Initiative), and the U.S. Army Corps of Engineers.

Objectives

  • Construction of a water control structure at the bottom of Spirit Mountain Ski Hill to direct excess flow away from the creek and directly to the river through a dual-use pipe that will also be used to pump water up the hill from the estuary for snow making.
  • Implementation of best management practices on the ski hill to reduce run-off and erosion, including construction of several settling basins.
  • Restoration of approximately 6,500 lineal feet of the creek channel.
  • Replacement or removal of three culverts.
  • Removal of a remnant causeway and culvert destroyed during the 2012 flood and restoration of the creek channel.
  • Restoration of the riparian floodplain impaired by the 2012 flood as well as restoration of a resilient stream channel.

Restoration Timeline

  • 2015 - Construct Spirit Mountain water control and water uptake structures.
  • 2015 - Implement restoration objectives in the tributaries of Knowlton Creek.
  • 2016 - Implement restoration objectives in the main stem of Knowlton Creek.

Maps