No relief in sight for declines in Great Lakes water levels

What goes up must come down and for Lake Erie there hasn't been much of that from its upstream, larger siblings.

After a lengthy period of climatic dryness and warmth, the Great Lakes are all suffering from low water levels, in some cases, historical low levels, government statistics demonstrate.

Covering 100,000 square miles the Great Lakes combined are easily the world's largest fresh-water reserve, a system long coveted by water-thirsty states to the south and west.

Thing is, the Great Lakes' low water levels are hampering everything from commercial shipping to recreational boat launching to sport fishing.

Even the Leviathan of the system – Lake Superior – has seen its water level drop below its long-term average for the past 12 months.

And in December of last year lakes Huron and Michigan saw their collective water level plummet to an all-time low. This water level drop also was the 14^th consecutive year in which the lakes Michigan and Huron basin experienced below average levels.

While lakes Michigan and Huron are independent water bodies they are twins in respect to the fact their elevations are identical and are co-joined at the hip at Mackinac, Mich.

Associated problems for all of the Great Lakes has not just been a long-term lack of snow that produces water-recharging run-off but also longer stretches in which the lakes are exposed to evaporation due to a general shortening of winter-time freezing and the resulting ice cover, water experts say.

What's even more alarming is that evaporation rates are climbing while precipitation rates generally are not, says scientists, including those with AccuWeather, the world's largest private weather-forecasting company and others.

“The water loss due to evaporation was a huge factor in the declining water levels of 2012,” said the U.S. Army Corps of Engineers in its Great Lakes Update for 2012.

This evaporation rate cannot be dismissed, either, reflects the Corps report.

Individual markers for each of the Great Lakes demonstrate a slow but steady rate of evaporation for each of the past five decades with the projection for the current decade indicating not only continued evaporation losses but potentially some acceleration, notably so for lakes Superior and Erie.

And the comprehensive data collected and maintained by the Corps is reflecting continued low water conditions for at least four of the five Great Lakes over the course of 2013.

This, in spite of the fact that in early spring the Superior and Michigan-Huron basins each experienced good water recharge.

That being said, the news remains less than encouraging.

“Lake Superior continues its 14-year stretch of below (long-term average) water levels, the longest period of below average levels in its recorded history dating back to 1918.

“Precipitation on the Lake Superior basin was well above average in May at 158 percent; however, precipitation has been below average over the past 12 months,” says the Corps' latest Great Lakes Water Level Summary.

Only a glimmer of good news is to report for Lake Superior this year as water levels will be as much as nine inches above where they were last year at the same, though still up to seven inches below their long-term averages.

The situation is much, much worse for the combined lakes Michigan-Huron basin, however.

For this massive natural bathtub the immediate water levels will run 17 to 20 inches below its long-term average, says the Corps in it latest Great Lakes Water Level Summary.

And that spells problems for its down-stream dependents, lakes St. Clair and Erie.

Over the next six months Lake St. Clair will remain nine to 11 inches below its long-term average, Lake Erie will be stuck at six to eight inches below its long-term average.

Only Lake Ontario may be spared in the six-month period where the Corps' best guess is that the water level may range from two inches below to five inches above its long-term average.

Lake Ontario also may see its level rise 15 inches above where it was last year at the same time through at least November.

However, the Corps notes, Lake Ontario's basin has been receiving less than average amounts of precipitation.

- Jeffrey L. Frischkorn
JFrischk@Ameritech.net