The Sweetwater Seas - A Documentary About the Great Lakes

Some Facts About the Great Lakes

Of all of the water on earth, only about 2.5 percent is fresh—able to support human and natural systems on land. Nearly 99 percent of that fresh water is frozen in glaciers or icecaps or trapped beneath the surface in aquifers. Only a bit more than 1.2 percent of the earth's fresh water is on the planet's surface, and a lot of that is unusable, locked in permafrost or ground ice. Lakes hold 21 percent of the surface fresh water in the planet—or about 0.007 percent of all the earth's water. This tiny percentage sustains almost all of the planet's non-oceanic life.


North America's Great Lakes contain a little more than one-fifth of the world's fresh surface water. They store 95 percent of the U.S. supply of surface water; 84 percent of the surface water in North America. Spread evenly across the continental U.S., the Great Lakes would submerge the country under about 9.5 feet of water.


The surface area of the lakes is more than 94,000 square miles/244,000 square kilometers of water (larger than the states of New York, New Jersey, Connecticut, Rhode Island, Massachusetts, Vermont, and New Hampshire combined, or about 23 percent of the province of Ontario). The watershed covers about 295,000 m2/767,000 km2.


United States and Canada - 10,900 mi/17,549 km (of shoreline, including connecting channels, mainland and islands). The Great Lakes shoreline is equal to almost 44 percent of the circumference of the earth. Michigan's Great Lakes coast totals 3,288 m/5,294 km, a longer coastline than any state but Alaska.

Great Lakes
Lake Ontario

Lake Ontario is the fifth largest of the Great Lakes in surface area and ranks as the 17th largest lake in the world. Lake Ontario is similar to Lake Erie in length and breadth (193 miles by 53 miles). Yet with its greater average depth (approximately 283 feet), Lake Ontario holds almost four times the volume (395 cubic miles) and has a retention time of about 6 years. Major urban industrial centers, such as Hamilton and Toronto, are located on its shore. The U.S. shore is less urbanized and is not intensively farmed.


Champlain first called it Lake St. Louis in 1632. On a Sanson map in 1656, it remained Lac de St. Louis. In 1660, Creuxius gave it the name Lacus Ontarius. Ontara in Iroquois means “lake,” and Ontario, “beautiful lake.”


Length - 193 Miles
Breadth - 53 Miles
Depth - 283 Feet Average
Depth - 802 feet Maximum
Volume - 393 Cubic Miles
Shoreline Length - 712 Miles
Water Surface Area - 7,340 Square Miles
Water Retention/Replacement Time - 6 Years
Outlet - Saint Lawrence River to Atlantic

Population - 5,600,00


Lake Ontario

Lake Erie

Lake Erie is the smallest of the Great Lakes in volume (119 cubic miles) and is exposed to the greatest effects from urbanization and agriculture. The average depth of Lake Erie is only about 62 feet (210 feet, maximum). It therefore warms rapidly in the spring and summer and frequently freezes over in winter. The drainage basin covers parts of Indiana, Michigan, Ohio, Pennsylvania, New York and Ontario. Because of its fertile soils, the basin is intensively farmed and is the most densely populated of the five lake basins. Lake Erie is the fourth-largest of the Great Lakes and ranks as the 13th largest lake in the world.


The greater part of its southern shore was at one time occupied by the Eries, a tribe of Indians from which the lake derived its name.


Length - 241 Miles
Breadth - 57 Miles
Depth - 62 Feet Average
Depth - 210 feet Maximum
Volume - 116 Cubic Miles
Shoreline Length - 871 Miles
Water Surface Area - 9,910 Square Miles
Water Retention/Replacement Time - 2.6 Years
Outlet - Niagara River & Welland Canal to Lake Ontario

Population - 12,400,000


Lake Erie

Lake Huron

Lake Huron is the third largest of the lakes by volume, with 850 cubic miles of water. Lake Huron is hydrologically inseparable from Lake Michigan, joined by the wide Straits of Mackinac. The Huron lakeshore extends 3,827 miles, and is characterized by shallow, sandy beaches and the rocky shores of Georgian Bay.  Lake Huron’s drainage area, is more than twice the size of Huron’s approximately 23,000 square miles of surface water. The Saginaw River basin is intensively farmed and contains the Flint and Saginaw-Bay City metropolitan areas. Lake Huron is the second largest of the Great Lakes and ranks as the fourth largest lake in the world.


Since its French discoverers knew nothing as yet of the other lakes, they called it La Mer Douce, the sweet or fresh-water sea. A Sanson map in 1656 refers to the lake as Karegnondi.


Length - 206 Miles
Breadth - 183 Miles
Depth - 195 Feet Average
Depth - 750 feet Maximum
Volume - 849 Cubic Miles
Shoreline Length - 3,830 Miles
Water Surface Area - 23,000 Square Miles
Water Retention/Replacement Time - 22 Years
Outlet - Saint Clair River to Lake Erie

Population - 3,000,000 US & Canada




    Lake Huron

Lake Michigan

Lake Michigan, the second largest Great Lake by volume with just under 1,180 cubic miles of water, is the only Great Lake entirely within the United States. Averaging 279 feet in depth, the lake reaches 925 feet at its deepest point. The drainage basin, approximately twice as large as the 22,300 square miles of surface water, includes portions of Illinois, Indiana, Michigan and Wisconsin. Lake Michigan is hydrologically inseparable from Lake Huron, joined by the wide Straits of Mackinac.


Champlain called it the Grand Lac. It was later named “Lake of the Stinking Water” or “Lake of the Puants,” after the people who occupied its shores. Through the further explorations of Jolliet and Marquette, the “Lake of the Stinking Water” received its final name of Michigan. An Indian name for Lake Michigan was “Michi gami.”


Length - 307 Miles
Breadth - 118 Miles
Depth - 279 Feet Average
Depth - 923 feet Maximum
Volume - 1,180 Cubic Miles
Shoreline Length - 1,640 Miles
Water Surface Area - 22,300 Square Miles
Water Retention/Replacement Time - 99 Years
Outlet - Straits of Mackinac to Lake Huron
Population - 12,052,743




Lake Michigan
Lake Superior

Not only is Lake Superior the largest of the Great Lakes, it also has the largest surface area of any freshwater lake in the world. With an average depth approaching 500 feet, Superior also is the coldest and deepest (1,332 feet) of the Great Lakes. The drainage basin, totaling 49,300 square miles, encompasses parts of Michigan, Minnesota, Wisconsin and Ontario.


The first French explorers approaching the great inland sea by way of the Ottawa River and Lake Huron referred to their discovery as le lac superieur. Properly translated, the expression means “Upper Lake,” that is, the lake above Lake Huron. Kitchi-gummi, a Chippewa Indian translation, signifies Great-water or Great-lake. A Jesuit name, Lac Tracy, was never officially adopted. An Indian name for Lake Superior was “Kitchi gami” (or “Kitchi-gummi”).


Length - 350 Miles
Breadth - 160 Miles
Depth - 489 Feet Average
Depth - 1,333 feet Maximum
Volume - 2,935 Cubic Miles
Shoreline Length - 2,730 Miles
Water Surface Area - 31,700 Square Miles
Water Retention/Replacement Time - 191 Years
Outlet - Saint Mary’s River to Lake Huron

Population - 673,000




Lake Superior


The Sweetwater Seas