revision preference src: Because of its sheltered location, Todd Lake has distinct thermal stratification levels within its water column. As a result, water below 15 feet (4.6 m) in depth remains extremely cold even during the summer. <SEP> tgt: Because of its sheltered location, Todd Lake has distinct thermal stratification levels within its water column. Water below 15 feet (4.6 m) in depth remains extremely cold even during the summer.