Climate change is not the only culprit

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Pavement and rooftops push water into the Great Lakes at an accelerated pace. (Photo courtesy of AmericanRivers.org)

Whether or not the current high water levels in the Great Lakes is the result of man-made climate change is debatable.

A dozen years ago the same experts now pinning the high water in the Great Lakes on climate change were just as positive the then near-record low water levels in the lakes were caused by the same thing.

I don’t know, maybe climate change is the culprit, maybe it’s a hoax, but I know a couple of  man-made changes to the environment are partially to blame for the current high water levels and seldom get much blame. More than a few inches of the extra water currently over-filling the Great Lakes comes from wetland loss in the Great Lakes watershed and the ever increasing amount of impervious surfaces covering the land.

Seventy-percent of the coastal wetlands that existed in pre-settlement times have been lost here in Michigan. Other states produce similar numbers or worse. Illinois, for instance has lost over 95 percent of the wetlands that formerly existed in it’s Lake Michigan drainage. One translation of the word “chicago” in Native American languages is “smelly swamp.”

Humans have often thought wetlands were smelly swamps, of little value and filling them in or draining them dry not only eliminated some of the stench, but turned the property into acreage of value. What they didn’t consider was the sponge-like manner in which wetlands soaked up precipitation in the warm months from direct rainfall, and in the spring from melting snow and ice.

Water stored in a wetland isn’t flowing directly into the lake or into the tributaries that empty into the lakes. Without them, lake levels quickly rise with each new rain shower.

Much of the rain that falls on unfrozen land is stored in the soil. It’s the water plants, crops and forests use to grow. That’s great where the land’s surface is covered with plants, crops or forests. But much of the land, in ever-increasing amounts, is covered by asphalt, concrete, homes, factories and other impermeable toppings.

What happens to all of the rain that falls on and snow that melts from roof tops, roadways and parking lots?  Most of it is channeled into storm drains, ditches or underground tiles that lead directly to the same lake tributaries flowing directly into the Great Lakes.

So whether or not man-made climate change is the culprit for the current high water in the Great Lakes, it’s not the only culprit. Wetland loss, channelization and ever-increasing amounts of impervious and non-porous surfaces are certainly exacerbating the problem.

Categories: Michigan – Mike Schoonveld

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