MINNEAPOLIS (WCCO) — Flooding on the Mississippi river is nothing unusual of course — unless it’s happening in January.

So one can imagine the surprise of some Champlin residents who awoke on Monday morning to find their parked cars surrounded by ice and water.

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They’re the victims of a rapid and dramatic rise on the ice-covered Mississippi river.

“Within 24 hours it went up eight feet,” explains resident, Jennifer Carlson.

Jennifer and Rick Carlson live on the Champlin side of the river, where riverfront walking paths are suddenly closed and underwater.

“If it keeps that up we could have a wet garage,” says Jennifer Carlson.

Blame it on the river’s ice pack. It’s breaking up and floating downstream, where it’s formed a natural ice dam that is blocking the river’s normal flow.

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“We had high water and ground that’s saturated and with the freezing temperatures the ice builds up and this causes ice dams and it just backs up,” explains Rick Carlson.

That backup is also causing the Rum River dam in Anoka to nearly disappear. The normal ten to twelve-foot drop over the spillway is shrinking rapidly.

Anoka Police Chief Eric Peterson says city crews are checking vulnerable infrastructure and have flood supplies on standby.

“We have plenty of sandbags should we need them. However, at this point it doesn’t appear we’re going to get to where we need to make bags available to the public,” explains Chief Peterson.

And a public that this time of year is used to shoveling snow, not pitching sandbags.

“The rapid rise is a little scary, but we’ll keep our fingers crossed,” says Jennifer Carlson.

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The National Weather Service flood forecast center expects the river to crest Monday evening and then decline gradually.