Causes of open water at middle slough of Sam Charley Island No flash player has been set up. Please select a player to play Flash videos. Video not playing? Update your browser or download the video clip Knut Kielland speculates on the causes of the open water spot on the middle slough of Sam Charley Island despite the cold air temperature. Process Observed: Open Water Date Process Observed: Thursday, February 2, 2006 Galleries: Midway down the middle slough of Sam Charley Island Gallery