The U.S. Army Corps of Engineers, St. Paul District, will start its annual Lake Pepin ice measurements Feb. 12

The Corps takes ice measurements on Lake Pepin annually to forecast the navigational outlook. The Lake Pepin ice thickness is measured because it’s the widest, naturally occurring part of the Mississippi River and is the last major barrier for vessels reaching the head of the navigation channel in St. Paul.

A Corps survey crew uses an airboat and a global positioning system to collect the data. The information is used by the navigation industry to predict when it’s safe to break through the ice and begin the 2020 navigation season.

The Motor Vessel Aaron F. Barrett was the first tow to pass through Lake Pepin last year and reach St. Paul on April 24. Historically the average date in which navigation is open occurs during the third week of March.

Ice measurements are typically completed weekly until the first tow arrives. Ice measurements are posted on the St. Paul District website at: