As Lake Michigan's water levels have droppedduring summer 2012, more than recreational fishers have taken note. Near the Shedd Aquarium, submerged rocks have already surfaced — new fixtures along the widening shores. Heather Charles / Chicago Tribune

By Cynthia Dizikes, Chicago Tribune reporter
19 October 2012

As Lake Michigan water levels have dipped lower and lower this year, so too has shoreline fisherman Patrick Finley.

A leisurely stand, cast and reel routine will no longer do. Actually catching a fish in such shallow water calls for methods more extreme.

"You literally have to lie down to land a fish with the net," said Finley, 30, who has been fishing the lake for about 20 years and works at Henry's Sport & Bait in Bridgeport. "The water is extremely low — the worst I've ever seen."

In fact, recent U.S. Army Corps of Engineers reports found that water levels on Lakes Michigan and Huron touched the all-time low for October one day last week and are likely to recede to record levels in the coming months due largely to this year's dry winter and relentlessly arid summer.

As the water has ebbed, more than recreational fishers have taken note.

Submerged rocks, trees and debris already have surfaced — new fixtures along the widening shores. Lakers carrying weighty cargo, like coal, iron ore and limestone, have had to lighten loads to make it to harbor. And for a few days this month, the corps limited the use of the Chicago Harbor Lock to prevent river water from running back into the lowered lake.

Though the lows have been driven by this year's weather, Lakes Michigan and Huron have drifted beneath their long-term average since the late 1990s, stoking worries that the Great Lakes, which contain a fifth of the world's surface fresh water — will become a consistently diminishing resource in the coming decades.

"People are concerned and worried and rightly so," said Tim Eder, executive director of the Great Lakes Commission. "What we are seeing could be connected to climate change. However, it is also important to note that the Great Lakes have always fluctuated."

Formed by retreating glaciers more than 10,000 years ago, the Great Lakes have been compared to "a series of interconnected bathtubs" that hold an estimated 6 quadrillion gallons of water, according to the commission. Water from Lake Superior — the headwater of the system — runs down to Lakes Michigan and Huron before flowing into Lake Erie, over Niagara Falls into Lake Ontario, and eventually the Atlantic Ocean.

Lakes Michigan and Huron, which hold about 2 quadrillion gallons of water, are mostly fed by precipitation and runoff. About 29 percent flows in from Lake Superior. On the flip side, about two-thirds of that water runs out to Lake Erie while about one-third is lost to evaporation. Illinois, meanwhile, diverts about 1 percent of the water from Lake Michigan for its own uses.

That complex balance has led to large and hard-to-predict fluctuations in water levels.

Since modern records began in 1918, the level of Lakes Michigan and Huron, which are considered one body of water connected by the Straits of Mackinac, reached an all-time low of 576.05 feet in March 1964 and an all-time high of 582.35 feet in October 1986, representing a sizable range of about 6 feet. […]

Although one daily mean water level this month reached the record low for October, the corps predicts that the overall monthly average will ultimately be about 1 inch above the record low.

After October, however, the forecast gets more dire, according to Keith Kompoltowicz, chief of watershed hydrology for the agency's Detroit district.

"The very abnormal weather that we have seen across the Great Lakes going back to last winter has really put us in the position to possibly set new record lows," Kompoltowicz said. […]

Dry summer helps push Lake Michigan water levels to near-record lows

0 comments:

 

Blog Template by Adam Every. Sponsored by Business Web Hosting Reviews