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Lake Michigan Field StationApril 7, 2000 — The Great Lakes are at the lowest water levels since 1965 and may reach new records this year unless there is an extremely wet spring and summer. "The lakes have not been this low since March 1965, and I'm concerned that recent growth in the Great Lakes shipping industry might evaporate with the water levels," said William M. Daley, U.S. secretary of commerce. "The near record low lake levels hurt shipping, but recreational boaters and marina operators suffer too."

Lower levels mean that the lake freighters that carry iron ore, coal, and limestone between Great Lakes ports such as Duluth, Minn., South Chicago, and Toledo, Ohio, cannot travel fully loaded because of the low water levels in the harbors and connecting channels. According to the Lake Carriers' Association, an organization that represents 11 companies operating 60 flag vessel operators on the Great Lakes, the lower levels mean each vessel forfeits between 70 to 270 tons of cargo for each one inch reduction in loaded draft.

"We are losing 8,000 to 9,000 tons per trip because of the lower levels," said Glen Nekvasil, Communications Director for the Lakes Carriers' Association in Cleveland, Ohio. "A major utility in the Great Lakes area burns about 22,000 tons of coal a day, so you can see what the loss of nearly half of that amount can mean." The association reports a 6.5 percent decrease in shipments of iron ore, coal, and stone in 1999, compared to 1998. Nekvasil said it is too early in this year's shipping season to make comparisons with last year.

"Lakes Michigan and Huron have set records by dropping nearly three feet in two years. While this will have major adverse impacts on commercial and recreational boating, on the plus side is that there will be the biggest beaches in 35 years and considerable less erosion. However, we may be seeing some new record lows on lakes Michigan and Huron in the late fall and winter," said Frank Quinn, senior hydrologist at NOAA's Great Lakes Environmental Research Laboratory in Ann Arbor, Mich.

Lakes Michigan and Huron have experienced a drop in levels of 2.9 feet over the past two years, the largest such drop in 140 years of record. Quinn noted that the unprecedented drop in levels over the past three years ended a 30-year run of above average and high lake levels. During the summer of 1986, Lake Michigan spilled over its banks and washed some lakefront homes off of their foundations.

A long-term cause of the drop in water level, according to NOAA climate experts, is that despite recent La Niña climate patterns, the region has experienced an over-riding long-term warming trend, which means less ice and more evaporation in winter months. Contributing more recently are hotter temperatures and lower amounts of rainfall, said Quinn. Last winter's warmer temperatures and below average precipitation meant that there was less winter snow, which the lakes require for the normal spring lake level rise. In addition the hotter temperatures increased the lake evaporation and reduced the runoff in the tributary streams.

"Many of the streams also have been at record low flows for this time of year, so not as much water is going into the lakes from those sources," Quinn said.

The little snow that did fall in the region melted in late February and early March and is already in the lake system. NOAA's outlooks are for normal to dry conditions this spring and summer.

Because the lakes are at low levels—in the case of lakes Huron and Michigan as much as 18 inches below average—commercial shippers cannot fully load their freighters for fear of running aground in channels and ports. Recreational boaters may have difficulty finding docking space, especially if the craft has a deep fixed keel.

The Great Lakes are Huron, Ontario, Michigan, Erie, and Superior. Their shoreline touches eight states and the Canadian province of Ontario.

More Information
NOAA's Great Lakes Environmental Research Laboratory

NOAA's Drought Information Center

Great Lakes Surface Environmental Analysis

Lake Michigan Field Station—Muskegon, Michigan—Live Web Cams

NOAA Media Contacts:
Jana Goldman, NOAA Research, (301) 713-2483 ext 181