The Great Lakes' water levels are rising. The entire Great Lakes system has gained an incredible amount of water just in the first 12 days of April.

Recent wet weather, combined with the seasonal lake level rise due to earlier snowmelt, are causing the Great lakes to rise.

Look at these numbers -- the amount of water each of the Great Lakes has added since April 1:

-- Lake Superior has risen 0.96". According to Keith Kompoltowitz at the U.S. Army Corps of Engineers, a one-inch rise in Lake Superior corresponds to 550 billion gallons of water.

-- Lake Michigan and Lake Huron are the same lake for water level purposes, since they are connected at the Straits of Mackinac. Lake Michigan/Lake Huron has risen 3.2" in the past 12 days. With that rise in water levels, 2.5 trillion gallons have been added to those two lakes.

-- Lake Erie is up 3.7" since April 1, meaning it has another 481 billion gallons.

-- Lake Ontario is almost 10" higher in the past 12 days. Tack on another 1.6 trillion gallons.

If we put all of the water gains together from each lake, the Great Lakes have added 5.1 trillion gallons in the last 12 days.

That's enough water for all 318 million Americans to satisfy our daily total water use for 164 days.