First official ice measurements by the U.S. Army Corps of Engineers in 2021 come in below average. 7:25 am, Feb. 10, 2021 × Bill Chelmowski, boat operator for the U.S. Army Corps of Engineers, St. Paul District, digs a hole to measure the ice on Lake Pepin Tuesday as part of the Corps' annual survey of the ice thickness on the lake. Tuesday's measurements were thinner than the average for this time of year. (Brian Todd/btodd@postbulletin.com) OLD FRONTENAC — Never has thin ice been so welcomed. Tuesday, a crew from the U.S. Army Corps of Engineers, St. Paul District took its first official ice depth measurements of Lake Pepin for the 2021 season. The measurements are used to help the navigation industry determine when it is safe to start moving commerce up and down the Mississippi River on barges.