Flood — Koochiching, Minnesota

2022-07-01 to 2022-07-11 · near International Falls, Koochiching, Minnesota

Event narrative

Above normal snowfall for the 2021-2022 season was observed across northern portions of Koochiching and St. Louis counties and much of that remained on the ground into April. Heavy rainfall then fell on top of that above normal snowpack at the end of April and sent abnormally high amounts of runoff into the Rainy River Basin leading to rises on Rainy Lake. International Falls experienced their wettest April on record, helping to set the stage for the flooding. By June 15th, the level of Rainy Lake reached 1113.2 feet which was 22 inches above the 2014 peak level and 2.5 inches above the all-time record set in 1950. Having crested and setting a new all-time high, the lake level fell over the remainder of the month to 1112.4 feet (13 inches above 2014 peak and slightly below the 1950 record) by the start of July. The high lake levels led to extensive damage to properties adjacent to the water along with damage to docks and other infrastructure. Lake levels would continue to fall into July and the Flood Warning was canceled on July 11th. Levels on Rainy Lake remained above normal at this time, but were receding and the threat for additional flooding had ended. State and Federal disasters were declared for the event with millions of dollars in infrastructure damage and property loss.

Wider weather episode

Spring snowmelt, record April precipitation and frequent May rain events led to strong hydrologic responses within the Rainy Lake basin. Namakan Lake, Kabetogama Lake and Rainy Lake rose above the flood of record during the months of May and June before subsiding in July and returning to levels closer to normal. These high lake levels led to significant damage to homes and businesses along the shoreline along with docks and other related structures. Additionally, some roads were covered in water with one being temporarily raised to maintain access to a few resorts. In addition to the costs of the damage itself, many resorts in the area suffered from lost revenue by having to close during the beginning of peak tourist season in the area.

View location on OpenStreetMap → (48.6000, -93.4670)

Source: NOAA Storm Events Database, event_id 1045809. Narrative written by the NWS forecast office that issued the report.