SIOUX FALLS, S.D. (KELO) — With temperatures rising as we move into spring, eyes in Sioux Falls are turning to the massive snow mounds and other sources of snow melt feeding into the city and minds are wondering; ‘Where will it all go?’

Monday afternoon, we spoke with Dustin Hansen, Sioux Falls Street Operations Manager, about the subject.

Snow pile in Sioux Falls in January 2023

The piles in Sioux Falls are no longer quite as white and crisp as they once looked, for as the snow has melted, sediment suspended within it has become more visible, leading to a view less like the one above and more like this below.

Dirty snow at a dump site in March 2023

There are two major water systems in Sioux Falls, with three total parts to them. One is the Big Sioux River, which winds its way through the city. The Big Sioux is also connected at two points by a diversion canal. The last waterway is Skunk Creek, which comes into Sioux Falls from the west and enters the Big Sioux along Louise Avenue north of 41st Street.

While there are nine different city snow dump sites, the main two are near the Household Hazardous Waste Facility off Cliff Avenue and south of the fairgrounds north of 12th Street.

Each of these sites lie along the Big Sioux, which Hansen says is the answer to where the snowmelt will go.

“We’ve got nine sites across the city, and each one will slowly melt,” Hansen said. “Even when it’s a good 60, 70, 80 degrees, the piles will melt slowly.”

Hansen said the sites where the snow sits have been selected so that as it melts, the run off runs through vegetation on its way to the river, “to kind of filter out that sediment,” he explained.

It’s not only sediment in the pile, Hansen notes, but also a lot of trash. “When we’re picking up snow, we pick up a lot of trash, a lot of sediment – so that material will actually stay on the site.”

Garbage in the snow pile

Since the snow melts slowly and filters through a stretch of vegetation, the trash will mostly settle onto the ground where it was dumped. Once the snow is all gone, the sediment and garbage will be collected.

Despite the large amount of snow this winter, Hansen does not anticipate flooding in Sioux Falls.

“We’ve actually been meeting internally with our team of emergency management here in Sioux Falls, and the flooding risk is fairly low,” Hansen said. “It’s probably even lower now that we’ve had some nice melting weeks — unless we were to get a really hard, heavy rainfall — the river’s got a lot of capacity in it.”

One defense against flooding is the aforementioned Big Sioux diversion canal.

Diversion canal spillway

“It plays a huge role,” said Hansen. “Obviously our levee system around Sioux Falls plays an immense role in keeping the city flood-free — it plays an immense role.”