The City of Two Harbors, Minnesota, is located along the shore of Lake Superior approximately 25 miles north of Duluth. Although this small city is home to just under 3,700 people ("Two Harbors - Minnesota"), significant amounts of logging, railroad development, and urbanization upstream have altered the hydrology within the Skunk Creek watershed (Jaschke, 2012). In the last century the quantity and velocity of runoff from the surrounding landscape into Skunk Creek, a tributary located within the community, have increased substantially (Seidel Interview, 2014). In July of 1999, Two Harbors experienced a 100-year storm event with catastrophic consequences (Seidel et al. 2012). Private property, city infrastructure, roads, and highways were extensively damaged. In addition, streambank erosion and pollutants from runoff threatened the quality of the water being taken into citizens' homes from an inlet just a half mile down-shore, thereby necessitating additional treatment. When taken into consideration, these impacts and threats prompted city-wide recognition and support for immediate action in terms of stormwater management (Seidel Interview, 2014).
As the flood waters receded, County Soil & Water Conservation District (SWCD) staff and University of Minnesota Extension personnel began assembling a team of individuals to create a stormwater management plan for the City of Two Harbors (Seidel Interview, 2014). With the help of a grant from the Minnesota Lake Superior Coastal Program, the City of Two Harbors completed its stormwater management plan just two years after the flood. Since then, the city has invested just over $80,000 of its own money into its stormwater infrastructure. With this, and matching funds from various competitive grants, the following projects were completed: 3 flood control basins, 2 stream bank stabilization projects, 1 rain garden, and additionally, a Two Harbors Urban Forest Management Plan that had an emphasis on stormwater management was developed (Seidel et al. 2012). These stormwater system enhancements were designed to be resilient to a range of conditions varying from the 100-year to the 500-year flood event (Jaschke, 2012; Kohn Interview, 2014).
In the summer of June of 2012, this newly reinforced stormwater system proved itself when it sustained the infamous "Solstice Flood." In just 48 hours northeastern Minnesota saw 8-10 inches of rain fall onto its already-saturated soils. As a result, nearly all of the rain that fell immediately ran as surface runoff down the steep to moderate hillsides for which the region is known, washing out roads and bridges, uprooting trees, dislodging boulders, and carrying massive quantities of debris and sediments directly into Lake Superior ("2012 Solstice Flood"). Days after the storm had passed, the floodwaters continued to rise in the St. Louis River, a 12,000 acre estuary which flows directly into Lake Superior ("Minnesota: St. Louis River Estuary"), before finally peaking at a record-breaking 16.62 feet. In the city of Duluth alone, the flood forced more than 250 residents to evacuate their homes and caused an estimated $100,000,000 worth of damage ("2012 Solstice Flood").
By comparison, the City of Two Harbors weathered the storm and resulting flood with relative ease. Equipped with sufficient stormwater drainage for a flood-event of this scale, Two Harbors escaped with only minor damages to public infrastructure and private property (Jaschke, 2012). Local officials, Board of Soil and Water Resources staff, and local residents in northeastern Minnesota have since then looked to Two Harbors as an exemplar for resilient stormwater management and planning. Additionally the combined efforts and investments of all involved have been credited with potentially preventing millions in flood damage ("Flood recovery efforts get boost from Minnesota grants").
To learn more, click the map below and take a tour of the Two Harbors stormwater infrastructure system.