With warm weather, melting snow, and rain possible, efforts are underway to prevent a repeat of an incident last September that buried a St. Croix River creek in sand.

The solar energy company that manages the Scandia site owned by James Zavoral has put heavy equipment operators to work this week. They are excavating retention ponds to increase holding, and have built a higher wall at the spot where stormwater escaped the site and rushed down the bluff and the creek last fall.

After a 4-inch rainfall on Sept. 20 last year, Middle Creek, a spring-fed stream below the site, was inundated in sand and sediment. The bluff and a wetland at its base were also damaged.

The Minnesota Pollution Control Agency says its investigation of the incident is ongoing and therefore it can’t provide comment at this time.

Numerous questions remain, including why the retention basins were not scraped before the solar farm was built, as was required in the permit.

Wendy Green of BHE Renewables, the company which owns the solar energy system, told the Scandia City Council in February that the changes would be able to contain back-to-back 100- year flood events.