Largest lakes & reservoirs in Southern Illinois by water volume

The estimated volume of water that a lake contains is measured at the lake’s normal elevation. By this measure, the world’s largest freshwater lake is Siberia’s Lake Baikal.

Water Volume can be measured in acre-feet, in cubic miles, or in cubic kilometers. One acre-foot is the amount of water needed to cover one acre (43,560 square feet) to a depth of one foot. One cubic mile equals 3,379,200 acre-feet. One cubic kilometer equals 810,713 acre-feet. 1 acre-foot is equal to 325,851 US gallons. Siberia’s Lake Baikal contains about 6,276,367,740,000,000 gallons of freshwater – nearly 1 million gallons for every living person on earth.

The other – and more widely used – measure of a lake’s size is the lake’s surface acreage. By that measure, the world’s largest freshwater lake is North America’s Lake Superior.

Note: In the United States, an acre foot is a unit of volume used to refer to large-scale bodies of water. It is defined by the volume of water needed to cover 1 acre of surface area to a depth of 1 foot.

You can find many of the the world’s largest lakes (by water volume) on LakeLubbers. Note: For some lakes, the water volume data is unknown or does not apply, so you may see fewer lakes than the total 10 articles we have published for Southern Illinois lakes.

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Below are lakes within USA > US Midwest Region > Illinois > Southern Illinois > Compared by water volume. This list does not represent all lakes in Southern Illinois, only the 10 Southern Illinois lake articles we have published on the LakeLubbers website.