Kinni River Monitoring

Project Approach

There has been a lot of concern about how new developments will affect the river, not only by the increase in runoff and chemicals from lawns, cars, etc., but also from pedestrian traffic. As the Kinnickinnic River is one of the best cold water streams in the state, there is a great concern to keep the aquatic community in the river healthy. In order to take an active role in the river's health and well being, the city has implemented a testing program aimed at evaluating the effectiveness of our Storm Water Management Ordinance in preventing degradation of the Kinnickinnic River due to new city developments.

From 2004 to 2012 the project took a two pronged approach. First an "upstream / downstream" view to see if the suspected source of a problem (new developments) will make river conditions worse downstream. Secondly, a more focused look at the actual performance of on-site storm water management practices that are incorporated within new developments under our current Storm Water Management Ordinance.

Beginning in 2013, the project scope was limited to the focused look at the actual performance of on-site storm water management practices within new developments.

Project Technical Consultant

The city has retained Short Elliot and Hendrickson (SEH) as a technical consultant for this project. SEH assists the city with the following:

• Coordination of monitoring components to ensure that all involved partners accomplish their pieces of the project as planned
• Integration and summarization of the monitoring results in a fashion that can be understood by all interested parties
• Preparation of an annual report summarizing results of the various monitoring components
• Providing general advice about shelters, product purchasing decisions, installation of various devices, or other matters of a similar nature

Project Background

A unique feature dominating the landscape of the City of River Falls is the Kinnickinnic (Kinni) River, a Class 1 trout stream that flows through the center of town. Recognizing the unique character of the Kinnickinnic, River Falls has invested time and money in the river corridor for the future enjoyment of fishing enthusiasts, hikers, canoeists and kayakers. The river is one of the premier naturally-sustaining trout fisheries in the Midwest, primarily producing brown trout. The Kinni arises from a series of large springs three miles north of Interstate 94, then flows southwesterly for 23 miles before entering the St. Croix River. In the vicinity of River Falls, the river is broad and shallow, averaging 40 feet wide and a foot deep.

Over the years, numerous projects have been implemented to protect and improve the condition of the river. In 2002, the city adopted the new Storm Water Management Ordinance, which is designed to protect the Kinnickinnic River from the negative impacts of stormwater runoff associated with new development.

Infiltration BMPs

The ordinance requires developers of new homes and businesses to utilize best management practices (BMPs) that infiltrate storm water runoff from rain events of 1.5 inches or less. Examples of these infiltration BMPs are grass swales, rain gardens, and large-development scale networks of ponds and infiltration areas. In the pond network, a wet detention pond collects and holds the storm water runoff and settles out pollutants such as suspended solids and nutrients. The cleaner water from the wet pond is gradually channeled to an infiltration area, where it percolates through the soil to recharge the groundwater system.