Credit: International Joint Commission
The Chicago diversion from Lake Michigan into the Mississippi River system is the only major diversion out of the Great Lakes Basin.
The Long Lac and Ogoki diversions into Lake Superior from the Albany River system in northern Ontario are the only major diversions into the Basin. The Long Lac and Ogoki diversions represent 6 percent of the supply to Lake Superior. (At present, more water is diverted into the Great Lakes Basin through the Long Lac and Ogoki diversions than is diverted out of the Basin at Chicago and by several small diversions in the United
The Welland and Erie Canals divert water between subbasins of the Great Lakes and are considered intrabasin diversions.
Aside from these major diversions, there are also a few small diversions:
- Forestport, New York diverts waters of the Black River into the Erie Canal and the Hudson River watershed
- Portage Canal diverts Wisconsin River waters (Mississippi Basin) into the Great Lakes Basin.
- London, Ontario, and Detroit take water from Lake Huron for municipal purposes. London and Detroit discharge their effluent to Lake St. Clair and the Detroit River, respectively
- The Raisin River Conservation Authority in New York takes water from the international section of the St. Lawrence River to maintain summer flows in the Raisin River
- The communities of Pleasant Prairie, Wisconsin, and Akron, Ohio, which lie outside the Great Lakes Basin take water from the Great Lakes on the condition that they return an equivalent volume of water over time to the Basin
- Haldimand, Ontario takes water from Lake Ontario
Diversions of water from the Great Lakes are currently negligible. However, an increasing number of droughts and climate change from global warming may result in more arid conditions in southern, central, and western US. Moreover, the US population is expected to swell by 50 percent – an additional 150 million people – in the next few decades, thus exacerbating water needs. As fresh water supplies are dwindling in the American West and South, and US states surrounding the Great Lakes experienced increasing pressure to divert water to dry parts of the country.
Water diversions from the Great Lakes on a large scale could have serious consequences. Proposals to divert water from the Great Lakes hydrologic system have proven very controversial.
Requests for Diversions and Exports of Great Lakes Water
As these lakes are a shared international resource, many governments and organizations are concerned with managing and protecting the integrity of the Great Lakes waters and ecosystem. For these groups, the bulk export of Great Lakes basin water became an increasing concern in a water-scarce world. In order to protect the Great Lakes from commercial interests hooking up pipelines and sending tankers to deplete the Lakes, the Great Lakes Compact was developed.
- 1981 Powder River Coal Company is denied a diversion of Great Lakes water to Wyoming to feed a pipeline that would carry coal slurry to the Midwest.
- 1982 The U.S. Army Corps of Engineers studies and denies a diversion of Great Lakes water to recharge the Ogallala Aquifer that underlies 8 states from South Dakota to Texas.
- 1990 Pleasant Prairie, WI, gains approval for a temporary 3.2 mgd diversion from Lake Michigan for public supply. The village must return treated wastewater to the lake by 2010.
- 1992 Lowell, IN, is denied a 2 mgd diversion for public supply (vetoed by governor of Michigan).
- 1998 Akron, OH, gains approval for a diversion from Lake Michigan of up to 4.8 mgd (an average 0.32 mgd is diverted) for public supply.
- 1998 The Nova Group gains a permit from the Ontario Ministry of the Environment to export approximately 160 million gallons per year (an average 0.4 mgd) of Lake Superior water to Asia in bulk containers. The permit is revoked due to objections of Great Lakes governors and citizens.
- 2006 New Berlin, WI, applies for 1.83 mgd (and up to 2.48 mgd by 2050) of Lake Michigan water for parts of the community outside the Great Lakes basin. As of early 2008, New Berlin is in discussions with Milwaukee about a potential sale of Great Lakes water, and has not resubmitted its application to the DNR.