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How much would Hurricane Harvey rain raise the Great Lakes?

Aug 30, 2017 10:12AM ● Published by Editor

An overhead view of the flooding in Houston, from Buffalo Bayou on Memorial Drive and Allen Parkway, as heavy rains continue falling from Tropical Storm Harvey, Monday, Aug. 28, 2017. ( Karen Warren/Houston Chronicle via AP)(Karen Warren)

Hurricane Harvey has produced historic rainfall amounts in southeast Texas. If we took all of that rain and dumped it in the Great Lakes, it would raise the world's largest freshwater source significantly.

The current estimate of total gallons of rain from Hurricane Harvey is 19 trillion. Ryan Maue of gives this estimate using doppler radar rainfall estimates. Maue looked at how much rain fell over the surface area affected by Hurrican Harvey.

Some areas of Texas have tallied nearly 50 inches of rain. 

What if we took that 19 trillion gallons of water and dumped it in the Great Lakes? How much would the water levels go up in the Great Lakes.

For a one inch rise in water level on a Great Lake:

Lake Superior needs 550 billion gallons

Lake Michigan & Lake Huron need 790 billion gallons

Lake Erie needs 170 billion gallons

Lake Ontario needs 120 billion gallons.

So to lift the water level of the entire Great Lakes just one inch, it would take 1.63 trillion gallons.

The 19 trillion gallons of rain in the past few days over Texas would raise the the entire Great Lakes 11.66 inches. That's almost a foot of water over the entire surface of the largest fresh water lake system in the world.

If all the water went into Lake Superior, it would rise 34.5 inches - almost three feet.

Lake Michigan and Lake Huron would rise two feet.

Lake Erie would go up 111 inches. Obviously that's not possible. The lake would spread out in size before obtaining that size of water level rise.

Lake Ontario would rise 158 inches, or about 13 feet.

This should put the amount of rain from Harvey in perspective.

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