City of St. Clair Shores issued the following announcement on May 21.
Pre-filled sand bags located at the west end of the Civic Arena parking lot are NOT for residents or businesses to take and use. The pre-filled bags are for the Milk River sandbagging project and are NOT owned by the City.
Residents are welcome to fill their own sand bags with the pile of sand located in the Civic Arena parking lot. Empty bags can be picked up at the St. Clair Shores Department of Public Works building, located at 19700 Pleasant Drive.
Original source can be found here.