Managing Storm Water Sustainably through Better Engineering


Ramsey residents flock to the large, linear park in the center of town each summer, almost religiously. Some carry fishing poles or frisbees, others a blanket or lawn chairs, but they are all headed to the same place: The Draw. A 2.6 million gallon pond that doubles as a social hub for the city, The Draw is bordered by a stage and amphitheater on one side, with a large expanse of grass and parking on the other. Residents visit this unique water feature so often that it has become a natural part of the summer routine. But if you look closely, you will find that very little of The Draw is natural at all.

The Draw was constructed by the City of Ramsey in 2010 as a storm water retention pond in advance of the commercial and residential development anticipated in The COR—the mixed-use town center that surrounds the pond. Because the soil in Ramsey tends to be very sandy and porous, the pond was partially lined with an impermeable barrier so it retains water that can then be used to irrigate the surrounding park during the dry summer months. Unfortunately, this creates the perfect conditions for filamentous algae—also known as pond scum or water net—which thrives in stagnant, nutrient-rich waters with high levels of nitrogen and phosphorus. The single-celled algae reproduce rapidly to form long, hair-like strands that eventually coalesce into large, mat-like colonies that can cover the entire surface of the water body. During the summer months, the algae grow quickly enough to successfully outcompete more beneficial aquatic vegetation. In fall and winter, as the dying algae decompose and consume oxygen, the resulting low-oxygen environment can cause fish kills.

Since essentially all of the water that fills The Draw is storm water runoff from the surrounding area, it’s no surprise that the water contains nitrogen, phosphorus, and other pollutants picked up from nearby lawns, sidewalks, and streets. What is less clear, however, is how to go about fixing the problem. Problems with current storm water management practices are hardly unique to Ramsey, but limited budgets and preexisting infrastructure often make it difficult to do anything to address the issue. That is why John Gulliver, a professor of civil, environmental and geo-engineering at the University of Minnesota, has been focusing his research efforts on the implementation of novel storm water management practices and the mitigation of pollution from runoff in urban areas. Gulliver also imparts this knowledge to students in his Urban Hydrology and Water Quality class, which explores storm water management and water quality for small watersheds through theory and practical application.

Like many courses, Gulliver’s class often used fabricated datasets so students could apply the concepts they were learning to more life-like situations. In an ideal world, students would have had the opportunity to work with real projects rather than classroom exercises. But given the number of students in the class, which caters to both undergraduate and graduate students, Gulliver would have had to find multiple projects for his class each year. “You go out to somebody in the field and they might have one project, but not four or five projects,” Gulliver explained. To accommodate his entire class, this might mean working with city staff from multiple communities to identify projects and work out the logistics, always with the risk that the community partner might lose interest or decide to drop the project entirely mid-semester. Given the time and commitment required on Gulliver’s part, and the uncertainty inherent in working with a community partner, he simply did not feel comfortable introducing real-world projects into his course.

Dr. John Gulliver, College of Science and Engineering, U of MN

That changed, however, when Gulliver was approached by the Resilient Communities Project (RCP) for the first time in 2012. RCP not only finds a willing partner city that will commit to a year-long partnership, but also coordinates the logistics of individual projects as well. RCP provided the structure and reassurance that Gulliver needed to feel confident replacing the hypothetical projects in his course with real-world counterparts. “[The RCP approach] was an innovation that was needed for a long time,” he noted. Moreover, RCP continues to coordinate and support the project throughout the semester, ensuring that both the city staff and students understand and are working toward a common goal, and have the information and resources they need to succeed. “The RCP program provides a framework for [the students] to work from,” explained Gulliver.

Although RCP might make introducing experiential learning into their classes simpler for faulty, the program is ultimately intended to benefit their students. “Students are demanding these kinds of experiences and have expectations that they will have these kinds of engaged experiences,” explained RCP cofounder and Humphrey School of Public Affairs Associate Dean Carissa Slotterback. Introducing real-world projects in the classroom provides students with valuable hands-on experience in their fields, something that can provide a leg-up in the increasingly competitive job market they face upon graduation. “All students like real applications,” Gulliver remarked, and “it’s greatly improved my course.”

Over the years, Gulliver and RCP have collaborated on storm water management projects in four different communities. During RCP’s pilot-year partnership with Minnetonka, many of the ideas that Gulliver’s students put forward were adopted shortly after the partnership ended. According to City of Minnetonka staff, the student-recommended policies and practices that were implemented have resulted in a measurable increase in storm water runoff quality throughout the city.

Gulliver’s students hope to achieve similar success this year as they tackle urban hydrology issues in Ramsey. One team has been tasked with identifying innovative ways to control the growth of algae in The Draw. One obvious solution is to reduce the amount of nutrient pollution from runoff that enters the pond, but the team will explore other possible remedies as well, such as introducing a competing plant species or using creative algae-harvesting techniques.

A second student team will be exploring options for managing storm water runoff in a more urbanized area of the community, where rainfall and snow melt currently flow into Emerald Pond from nearby Emerald Pond Park and the surrounding residential neighborhood. As the impacts of climate change become more severe, storm events in Minnesota are expected to become more intense, potentially increasing both the volume and rate of storm water runoff. This in turn increases the risk of localized flooding and makes it easier for pollutants to find their way into Emerald Pond and other water bodies.

One way to combat these problems is to temporarily hold runoff in a retention pond to settle out suspended solids and pollutants. However, in already developed neighborhoods such as those around Emerald Pond, there is often insufficient room to construct such a system. Consequently, Gulliver’s students will explore other potential solutions, such as incorporating storm water filtration and retention systems during street reconstruction projects, encouraging land owners to plant vegetative buffers, and cultivating tree stands specifically designed to mitigate runoff pollution. With such systems in place, the detrimental effects of harsher storms and higher flooding will hopefully be lessened.

City of Ramsey engineer Bruce Westby and parks and public works superintendent Mark RIverblood have made it clear that these two projects are high on their list of priorities for this year’s partnership with RCP, and they are eager to work with Gulliver’s students. Ramsey is bordered by both the Mississippi and Rum Rivers, is home to several large lakes, and has protected wetland habitat over more than 15% of its land area, demonstrating the ecological, social, and economic importance of water to the community. Gulliver and his Urban Hydrology and Water Quality students are hard at work to ensure that the health of Ramsey’s water resources is not threatened.

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