Watch Bombuj. Freshwater is a documentary that dives into the cold waters of Lake Superior along Minnesota’s North Shore. Despite the fact that it contains ten percent of Earth’s freshwater, this massive force of nature remains largely unexplored. One group of people, however, is intimately aware of its power. From the surfers who catch its waves to the scientists who study its depths, learn why Lake Superior is a precious resource that should never be taken for granted.