WILLMAR — Residents in the city of Willmar are encouraged to do their part to keep city stormwater as free of pollutants as possible by participating in best management practices on their property.

Sara Sietsema, environmental specialist for the city of Willmar, shared some of those practices during her annual stormwater report to the City Council at the June 6 meeting. The report is a requirement for the Municipal Separate Storm Sewer System general permit program.

Stormwater is rain and snowmelt that drains off impervious surfaces, such as roads, sidewalks, driveways, parking lots and roof tops, into a city’s stormwater sewer system through catch basins or storm drains. It is then discharged untreated into lakes, rivers, streams and wetlands. The city’s stormwater system also includes driveways, parking areas, streets, alleys and sidewalks.

“Rain barrels are a gateway (best management practice),” Sietsema told the council. “You just put a rain barrel up and then you water your flowers and your garden, and then pretty soon you’re like, ‘Oh maybe I can have a rain garden.’ And then you’re like, ‘Maybe I want a bee lawn, I don’t want to mow this at all.’ It’s a gateway (best management practice) for stormwater.”

According to the Minnesota Pollution Control Agency, t he collected rainwater can be used for purposes that would otherwise require tap water. Also, the water captured and used for irrigation in yards and gardens, for example, removes solids, nutrients, metals, pathogens and toxins that would otherwise have drained into the storm sewer.

As part of the city of Willmar's rain barrel cost-share program , residents can purchase up to four rain barrels from the city at a reduced cost. The city purchases the rain barrels in bulk at cost to pass the savings on to residents, according to Sietsema. At this time, the cost per rain barrel is $55, according to the city’s website.

Another way in which residents can assist the city is by adopting a storm drain in the city and keeping it clean throughout the year, clearing it of leaves, trash, and other debris throughout the year.

To learn more about the adopt-a-drain or rain barrel cost-share programs, contact Sietsema at 320-235-4760 , ext. 7425.

Rain gardens can help to filter pollutants before water reaches the city’s stormwater system or groundwater. They are planted in a low area that allows rainwater runoff to soak in from hard surfaces like roofs, driveways, walkways and parking lots.

A rain garden also helps to prevent erosion by holding soil in place with the deep roots of the plants used. It also attracts birds and butterflies and requires little watering and maintenance once established, according to the University of Minnesota Extension website.

Kandiyohi County Soil and Water Conservation District can help residents determine if a rain garden is appropriate for their lawn and help with funds to install a rain garden on their property. To learn more about the rain garden program, contact the district at 320-235-3906 .

Other best management practices include “mowing in” when mowing lawns so that grass clippings don't end up in the gutter, using less salt on sidewalks and driveways, keeping leaves out of the gutter, and picking up pet waste. In fact, not protecting the stormwater system from these things can result in a misdemeanor charge since an update in June 2021 to the city’s surface water management ordinance.

Pollutants of concern include salt, sediment, grass clippings, leaves, pesticides and fertilizers, oil, litter, and pet waste. A more recent pollutant of concern is fluoride, which can harm aquatic habitats, according to Sietsema.

In 2018, the city started using brine when treating the streets for ice and snow during the winter months. “The brine is generally a more effective winter maintenance product than granular salt,” Sietsema said. Using brine has decreased the city’s salt use nearly 50%.

In order to reduce the amount of pollutants entering the city’s stormwater system, state permitting is requiring cities to create regulatory mechanisms regarding water volume, quality treatment requirements, proper salt storage and pet waste. Regulatory mechanisms could be an ordinance, rule or contract, according to Sietsema.

Another new requirement is to have a written snow and ice management policy, along with maintenance staff training.

“You’ll possibly see me several more times before the year’s end for those regulatory mechanisms,” Sietsema said.

There are six areas of the city stormwater prevention program :

An illicit discharge is any discharge to the stormwater system that is not composed entirely of stormwater, such as wastewater piping connected to storm drains and infiltrations from cracked sanitary systems. Recently the city of Willmar smoke-tested sections of the sanitary sewer in downtown and near the BNSF Railway yard and discovered an uncapped storm sewer cleanout in a private parking lot that was fixed and a section of severely deteriorated sanitary pipe that was relined to prevent stormwater contamination and groundwater infiltration.

The city prevents pollution in the stormwater system and practices good housekeeping of its own through its two street sweepers that operate when snow is off the streets. The street sweepers annually collect nearly 5,000 cubic yards of salt, sand, grass clippings, leaves and other debris.

“It is our responsibility to protect both the surface water and the groundwater from stormwater pollution,” Sietsema said.