High water on the St. Croix after headwaters hit by torrential rain, flash flooding

Six inches or more fell on parts of the upper St. Croix watershed, sending a lot of water downstream.




4 minute read

Evening update: Dam blows, bridges and roads out

Upper Tamarack River flooded near the confluence with the St. Croix River. (Photo courtesy Lee Lewis)

Heavy rains that fell on northern Wisconsin and Minnesota this weekend have created a virtual “wall of water” heading downstream on the St. Croix River. The precipitation has also caused road washouts and other damage near Superior, Wis., on rivers flowing into Lake Superior.

The St. Croix and its headwaters tributaries rose sharply in the past 24 hours, are still rising, and should be treated with extreme caution.

Many roads in the area are also closed due to washouts or floods. Do not drive into water over the road. Please travel safely and consult local authorities about conditions.

National Weather Service observers report:

  • 7.9 inches of rain near the headwaters of the Eau Claire River
  • Wisconsin Highway 35 at Riverside Landing on the St. Croix is closed due to flooding and water over the road.
  • Water over Denver Road from Ounce River, tributary of the Totogatic → Namekagon → St. Croix
  • 5.44 inches of rain at Hayward, Wis. (near Namekagon)
  • 5.94 inches at Minong, Wis. (near Totogatic)
  • 3.79 inches at St. Croix State Park, Minn. (near Kettle and St. Croix)

River flows

The river gauge at Danbury, Wis. shows the St. Croix rose more than five feet between yesterday morning and today.

The upper river is in full flood stage, having quickly passed seven feet — and still rising very fast.

Water level on the St. Croix River at Danbury. (Courtesy U.S. Geological Survey)

The Army Corps of Engineers reports the river has risen about three feet at Grantsburg in the past 24 hours.

From the flood front line

Residents of  Gordon, Wis. reported that the Eau Claire River, one of the St. Croix’s northernmost tributaries, was out of its banks beyond any level they could remember. Thank you to Erik Finstad for this photo:

Eau Claire River, Gordon, Wis., June 18, 2018 (Photo by Erik Finstad)

It’s a similar story on the other side of the state line, where Minnesota’s northernmost St. Croix tributary, the Upper Tamarack River, enters.

Lee Lewis, a St. Croix 360 reader, river protector, and cabin-owner on the Upper Tamarack reported his shack was flooded this morning, the first time since it was built in 1968.

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Cabin on Upper Tamarack River, courtesy Lee Lewis

“We bailed at about 5:30 this morning as the water was beginning to enter the cabin – & still rising fast – and we were concerned that we wouldn’t be able to get out if we waited until the coffee water boiled!” Lee wrote.

Others report that the St. Croix and Namekagon Rivers above Highway 70 are unsafe — please stay off the upper river for your own safety.

Please send updates and photos to St. Croix 360 using the handy contact form.

Dam in danger

A dam on the Upper Tamarack is now feared to be failing. Law enforcement reported an hour ago (12:36 p.m., Monday, June 18) that the Radigan Flowage Dam west of Dairyland is “likely to fail soon causing flash flooding downstream on the Tamarack River south of the dam as it flows towards the Saint Croix River.”

Heading south

The trillions of gallons of rain are now heading downhill, and the lower St. Croix will soon be affected. The National Weather Service predicts the river at Stillwater will rise quickly in the next couple days:

The water level is predicted to exceed 683′ on June 21, the point at which a no-wake zone is in effect on the St. Croix River.

Frequent freak floods

The intensity and timing of this storm is similar to a few others in the past several years, notably the Duluth and St. Croix River flooding in 2012, and July 2016, when the third-highest water level ever was recorded at St. Croix Falls.

Because warmer air holds more moisture, such storms are expected to increase due to climate change. While June has always been a stormy season in these parts, the floods seem to keep breaking records every few years.

The data below shows monthly mean flow for the month of June. Notice the slightly rising red trend line.

Data courtesy U.S. Geological Survey

Update, 9 p.m. June 18:

Evening flood update: Dam blows, bridges and roads out


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High water on the St. Croix after headwaters hit by torrential rain, flash flooding