When Samuel de Champlain arrived at Lake Huron in 1615, he knew he had encountered something astonishing. Before him was a vastness of water, an apparent ocean, yet the water was fresh—he called it La Mer Douce, the “sweetwater sea.”

Champlain could not have known that his hand had dipped up less than one cup of six quadrillion gallons of fresh water contained in five immense lakes—more than a fifth of the drinkable surface water on earth. Nor could he have dreamed that such a vast storehouse of water would prove fragile, vulnerable to near-catastrophic harm by the industrialized colonists who would soon populate their shores.

The Sweetwater Seas is a feature documentary and book that integrates science and fine-art videography to explore one of North America’s wonders. The film examines the latest thinking about the environmental sustainability of the Great Lakes Watershed and seeks to engage viewers into making a difference. Although 42 million people live within the Watershed, most have never been around their own lake, much less all five. We will take them on a voyage of discovery to rival Champlain’s.