Picture two very strong men lifting two bathtubs full of water over their heads and pouring the water down the side of a steep, tall hill right next to your house. Now picture that same volume of water pouring over the hill, continuously, during a large rainstorm. Dirt begins to wash away, chunks of the hillside cave in and tumble to the riverbank down below. A torrent of muddy water, mixed with twigs and leaves streams out into the St. Croix River, creating a dirty brown plume. Long after the rain has stopped, phosphorus from the water that came down the hill lingers in the river, feeding algae and other aquatic plants. By the end of the summer, portions of the river have taken on a greenish hue.
When the City of Lakeland met with the Middle St. Croix Watershed Management Organization (MSCWMO) eight years ago to discuss drainage problems on Quixote Ave., the two entities knew they were facing a formidable challenge. Because of the slope of the land, runoff from more than 12 acres of streets and homes was flowing down Quixote Ave. and over the bluff into the St. Croix River during large rain events. Over time, the runoff water had created a gully in the bluffline and people living in the homes nearby were beginning to worry about the rate of erosion. Additionally, water monitoring research has shown that the St. Croix River is becoming unhealthy due to excess phosphorus, most of which comes from stormwater runoff.
After an initial feasibility study in 2007, the city began implementing projects to capture runoff from small storms and soak the water into the ground before it could reach the bluffline. This included multiple raingardens installed between the years of 2009 and 2011.
Last week, Lakeland and the MSCWMO completed the finishing touches on a comprehensive project to address drainage, erosion, and runoff pollution problems along Quixote Ave. The $120,000 project included several components including building three more shallow raingardens, resloping and regrading Quixote Ave., building an iron-enhanced sand filter to pull phosphorus out of the street runoff, installing a pipe to convey water safely from the top of the bluff to the river during large storms, and restoring the hillside with native plants and shrubs to prevent further erosion. Funding for the project came from the Minnesota Clean Water Fund, a grant from the St. Croix River Association, City of Lakeland and the Middle St. Croix WMO.
The Quixote Ave. project demonstrates the importance of working collaboratively and using innovative approaches to address modern water quality problems. Altogether, the project will keep at least 8.5 pounds of phosphorus out of the river each year (the equivalent of 4250 pounds of algae), and will also keep more than 3000 pounds of soil in place along the bluff and out of the water each year. The approach is unique in that it addresses runoff from both small and large storms, and will also protect the river bluff and surrounding homes. None of this would be possible, however, without cooperation and good communication between the city, residents along the street, the Middle St. Croix WMO, and the multiple other agencies and organizations involved in the project.
Picture Quixote Ave. in the rain next summer. Some water flows into existing and new raingardens, some soaks into the landscape in other locations, some flows safely down a pipe to the river. On the hillside, new plants grow larger and their roots take hold. The river breathes a sigh of relief.