Original sentence: Balsam Lake is a lake located in the Kawartha lakes region of south central Ontario, Canada (coordinates ).However, navigable portions of the system formed by the Mississippi River and its tributaries are at elevations of over 305 m (1,000') above sea level.It is 16 km long and averages 3 km wide.Some claim that Balsam Lake, at  256.3 m (841') above sea level, is the highest point on Earth to which a boat can be navigated from sea level.This lake is the highest point of the Trent-Severn Waterway; from here, the waterway descends to Georgian Bay in the northwest, and to Lake Ontario in the southeast
Edited sentence: Balsam Lake is a lake located in the Kawartha lakes region of south central Ontario, Canada.However, navigable portions of the system formed by the Mississippi River and its tributaries are at elevations of over  above sea level, as well as the peak of the Rhine-Main-Danube Canal at.It is 16 km long and averages 3 km wide, though its actual width varies due to the many large bays the carve its shoreline.Some claim that Balsam Lake, at  above sea level, is the highest point on Earth to which a boat can be navigated from sea level.The lake is the highest point of the Trent-Severn Waterway; from here, the waterway descends to Georgian Bay in the northwest, and to Lake Ontario in the southeast