Lake Superior is at its lowest ebb in 80 years. Its surface has plunged a foot so far in 2007 and a further three-inch dip is predicted by the end of autumn. That's a lot of water to lose from a lake the size of South Carolina!

Temperatures are surging as water levels plummet. Lake Superior's average temperature has risen 4.5 degrees Fahrenheit since 1979, compared to a 2.7 degree rise in the region's air temperature during the same time. Surface temperatures on the western side have reached an unprecedented 75 degrees. The warm-up is particularly dramatic given Lake Superior's Ice Age glacier origins, and its usual reputation as the coldest of the Great Lakes year-round.

All of the Great Lakes have been shrinking and warming up. But the suddenness and enormity of Lake Superior's changes have shoreline residents, boaters, commercial and recreational fishermen, and scientists alarmed and scrambling for answers.

Swimming areas have become mud flats. Marinas are closed to boats and begging the U. S. Army Corp of Engineers to dredge impassably shallow harbors. Vessels are carrying lighter loads of iron ore to make it through shipping channels, costing industry millions of dollars in higher transportation costs and delayed production.

Interstate water piracy is suspected by some long-time Lake Superior residents. "That water is going west", Grand Marais retiree Ted Siestema vowed to the Associated Press. "That big aquifer out there is empty but they can still water the desert. It's got to be coming from somewhere."

But the Corps of Engineers says no to that theory. Water does leave Lake Superior through locks, power plants, and gates on the St. Mary's River, but in amounts strictly regulated by treaties with Canada since 1909; too little for too long to account for the sudden and dramatic drops observed since 1979.

The actual forces at work are more complex, says the Corps and most scientists. Precipitation over the Great Lakes has declined steadily since the 1970s; this year's rainfall is six inches below last year's. Milder winters have helped Lake Superior's ice pack melt earlier, boosting average temperatures. The warmer winters may be due to long-term global warming.

But other experts attribute Lake Superior's changes to lingering effects of El Nino, the cyclical warming of equatorial waters that brought dramatically warmer winters during the 1990s. An extended drought is happening, but it will end itself in an aeons-long natural cycle, they say.

Whether the decline of Lake Superior is temporary or irreversible, the Great Lakes and St. Lawrence Cities Initiative, a consortium of over 50 U. S. and Canadian municipalities surrounding the Great Lakes, is working to reduce urban areas' impacts upon Lake Superior, its four sisters, and the mighty St. Lawrence Seaway that connects them all to the Atlantic Ocean. From restricting power plant and industrial pollution, to ending the Coast Guard’'s live-fire artillery practice, the GLSCI works globally at the local level.

With Lake Superior water levels declining and drying up, it's time to sit up, take notice and start tending to water levels in your own back yard. There are possibly many environmental issues, as well as human actions, at play in the Lake Superior water level change. Take action so those issues and actions don't impact you.