Where has the water gone?
A lake in decline
By John Pepin
The Mining Journal
Published December 5, 2006
MARQUETTE — It may be snowing outside, but meteorologists say drier than normal conditions over much of the Upper Peninsula are expected to continue.
“We’re in a deficit for total precipitation,” said David Pearson, a meteorologist with the National Weather Service in Negaunee Township. “Since June, every month has been in a deficit.”
From June 1 through Oct. 31, the weather office in Negaunee Township was down a total of 6.6 inches of precipitation. Over the same period, the city of Marquette was down 5.7 inches; 1.2 inches lower than normal at the Houghton County Airport; 3.1 inches in Ironwood; 3.3 inches in Iron Mountain; and about a half inch down in Newberry.
So far this year, the Negaunee Township NWS office is down just a couple of inches below the normal snowfall total of 33.2 inches. Last year at this time, 46.6 inches of snow had already fallen.
All of the precipitation shortfalls are registering in much lower than usual river and stream heights and, although affected by a much larger set of variables, dramatically lower levels of Lake Superior.
Currently, the largest of the Great Lakes is down 17 inches below its long-term average beginning of December level and 13 inches down from the level recorded last year at this time.
“The last time Lake Superior was this low at this time of year was in December 1925,” said Carl Woodruff, hydraulic engineer for the U.S. Army Corps of Engineers’ Detroit District.
Lake Michigan and Lake Huron are also down from previous years and averages for this time of year. The levels of these lakes are expected to continue to decline over the next several months.
Gates at the Soo Locks are set to allow 55,100 cubic feet per second of water flowing from Lake Superior to lakes Huron and Michigan for the month of December, the same outflow as last month.
This year’s June through October period in Marquette County was the second-driest behind a record set in 1976. The city of Marquette recorded its third-driest sequence over the same time period.
Across Upper Michigan, low water levels have caused numerous problems from shallow waters for anglers and recreational boaters to a coal boat reducing shipments to the Smurfit Stone Container Dock, the Ontonagon area’s largest employer.
Michigan Department of Natural Resources Lake Superior Basin Coordinator Steve Scott in Newberry said low water levels can make winters more difficult for fish species, especially in smaller streams.
“It’s natural for all streams to go through drought periods as well as high water periods,” Scott said. “What can be a problem is prolonged periods of drought lasting several months.”
In some cases in winter, streams can freeze from the bottom up developing what is called “anchor ice,” limiting life for fish and other organisms at the stream bottom.
Brook trout are one of the cold water species susceptible to anchor ice and low stream level problems. Dry or flooding conditions may both be problems for fish laying eggs during spring or fall—the eggs may be washed away in floods or left high and dry in drought periods.
Low stream levels in summer give fish a smaller area to occupy and they concentrate in the remaining deep holes. These holes may be exploited if discovered by anglers.
Lake Superior water levels dropping may also cause problems for fish using the lake’s limited shoal areas offshore. Some species using this ecosystem include walleye, bass, pike and salmon, in their juvenile stages of growth, Scott said.