Middle Creek Calamity: Authorities investigate St. Croix River damage from stormwater pond overflow

Several tons of sand appear to have been deposited at the mouth of Middle Creek. (Greg Seitz, St. Croix 360)

Map showing approximate location of breach and course of overflow down the bluff and into Middle Creek. (USGS National Map)

The overflowing stormwater pond at the former gravel mine and current solar farm in Scandia has been the subject of continued attention over the past week. Since St. Croix 360 first reported the incident on Thursday, Sept. 27, other media outlets have picked up the story, including the St. Paul Pioneer Press, KSTP News, and the Country Messenger.

During a heavy rainstorm on Sept. 20-21, a basin at the edge of the bluff filled with runoff and then spilled over a containment berm. From there, a large amount of water flowed down the bluff, carrying what is now described as “100 tons” of sand into a spring-fed creek and the St. Croix River.

Recent reporting has revealed that a multi-agency team has been assessing the damage and planning for mitigation. Investigations are also underway into the cause of the incident.

“This was not only foreseeable, it was foreseen,” said Laurie Allmann, a watershed resident who was involved in fighting the gravel pit proposal. “Our earlier work when the site was being considered for a gravel mine made clear the inherent vulnerability of the site based on its hydro-geology.”

KSTP coverage

In a story on Sunday night, KSTP Eyewitness News reported both the Minnesota Pollution Control Agency and Department of Natural Resources are looking into the incident.

“The retention ponds here at the old gravel mine, which is now a solar farm, just did not hold the water,” Carnelian-St. Croix-Marine Watershed District administrator Jim Shaver told reporter Jay Kolls. “So, the MPCA and the DNR, along with probably the Wildlife Service at some point, will all be out here surveying what happened and working on remediation.”

Watch the report:

Pioneer Press

The St. Paul Pioneer Press reports that several local, state, and federal agencies are involved, and recently toured the site to see the damage firsthand. A DNR spokesperson told reporter Mary Divine that the agency had issued a violation notice to the company that owns a solar farm currently responsible for stormwater runoff at the site.

“It’s basically putting them on notice that we believe there was a violation and will likely be followed up with a restoration order,” Harland Hiemstra said.

Country Messenger

The city of Scandia, which had permitted three years of gravel extraction at the site in 2013, received a preliminary report at a meeting last week, according to the Country Messenger. Reporter Kyle Weaver says representatives of the solar company, gravel pit operator, and government agencies told the city council that it’s not possible to assign blame yet, and an investigation is needed.

“We obviously have a lot of examination and study to do to determine what happened,” said Jim Shaver.

The council may receive another report at its Nov. 7 meeting.