Ice and snow help slow evaporation of water on Great Lakes. Ice slows commercial traffic but it also means waters levels will be up.
“A brutally cold winter has covered the Great Lakes with more ice than they have seen since 1979. Special correspondent Elizabeth Bracket of WTTW reports on the struggle to keep shipping lanes open to Chicago’s ice-clogged harbor to Lake Michigan.”
Excerpt from Salon on Chicago river: More than a century ago in this exact spot, human ingenuity shaped nature to its will, smashing through the earthen barrier that separated the Mississippi River drainage area from the vast freshwater reservoir of the Great Lakes, stitching together the commercial energies and distinct ecosystems of the North American continent. The consequences of that decision are still playing out today in a metropolis where more than seven million people draw their drinking water from Lake Michigan — and where those same people pump their sewage back into the river. Myriad threats, from water pollution to flooding and invasive species, have made the question of what to do about the Chicago River one of the most important questions facing the city. And simply by asking it, Chicagoans are acknowledging a basic existential struggle. That struggle is between two competing visions. One is remedial and pragmatic, the province of engineers and bureaucrats. In their eyes, the river can and should be cleaned up only to the point where it can operate as a safe, functional waterway that exists to meet the demands placed on it by commerce, flood control, and the dispersal of wastewater. In the alternate vision, however, the river meets all of these demands — and more. Its proponents seek nothing less than to turn the Chicago River into a civic treasure, its newly cleaned banks lined with parks and homes and restored ecosystems, its very presence a clear and shimmering symbol of a great city built on making, trading, connecting: a symbol of American history’s inexorable flow toward progress. And in the bargain, they seek to make the river a living — and flourishing — example of environmental innovation and ecological stewardship, one that generations of Chicagoans will cherish. http://www.salon.com/2013/02/24/cry_us_a_river_partner/
According to the Sierra Club the message heard by commissioners at the summer 2012 International Joint Commission hearings on Great Lakes water levels was “Restore Our Water Levels.” For emphasis,Canadian Commissioner Lyall Knott said, “we hear you loud and clear – restore our water levels.” But the 1,200 attendees at the hearings do not like the recommendation of the IJC for them to ‘get use to lower water levels.’ The many stakeholders – land owners, fisheries, boaters, shippers, recreators, chambers of commerce, local services to name a few – are not satisfied with this answers. Stakeholders and local governments want viable options to address the issue of lower lake levels especially in Lake Huron-Michigan where the water levels are declining far more than the other lakes even if within historic ranges. This is alarming not only to the region but our national interests. Studies have been done ad nauseum on this issue. Dredging is an obvious solution but local funds are not sufficient to undertake this task. Shipping loads dwindle ton by ton as water levels decrease inch by inch and income dollar by dollar. Evaporation is the culprit. The graphs provided by the US Army Corps of engineers show the dramatic decreases and forecasts within the context of historic levels. See for yourself the power of climate and evaporation in the following picture of dry docks compliments of the Sierra Club of Canda.