Dry southern U.S. states will be unable to take massive sips from the Great Lakes-St. Lawrence basin under a deal reached today by Ontario, Quebec and other jurisdictions that border the waterways. The Ontario government called the Great Lakes-St. Lawrence River Basin Sustainable Water Resources Agreement an "historic" deal that will essentially prohibit massive, bulk water exports from the fresh-water lakes. Ontario signed the deal in Milwaukee alongside representatives from eight American states — Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin.

Quebec also signed the deal since the St. Lawrence River is connected to the Great Lakes, which account for one-fifth of the world's fresh water supply. The deal, which still requires endorsement by the U.S. Congress, is meant to prevent thirsty southern American states from diverting massive amounts of water to their own jurisdictions. It's more of a theoretical risk, but Natural Resources Minister David Ramsay said the deal was key to protecting Great Lakes water from drainage over decades to come.

"Primarily the pressures come from the southwest United States, the drier part of the continent," Ramsay told reporters at the Ontario legislature in Toronto. "We hear musings from time to time (from) southern California, Arizona, New Mexico of their challenges to supply fresh, potable water to their populations," Ramsay said. "They look north and they see the Great Lakes as the largest supply of fresh water in the world . . . and sometimes they get visions of sugar plums dancing in their heads, to use a seasonal analogy."

The deal is also meant to protect the water system from the environmental effects of large-scale diversions, however it does permit large amounts of water to be taken under some circumstances, including for bottled water. There were actually two agreements signed — a binding pact among the eight states and a "good-faith" agreement among the two provinces and eight states. Provinces and states are unable to sign treaties by themselves across international borders. Ramsay expected Congress would rubber-stamp the deal, saying it's ``fairly automatic" for Washington to acknowledge agreements already reached between states.

Still, each jurisdiction, including the Ontario and Quebec legislatures, will have to pass into law their commitments not to allow large-scale water diversions by jurisdictions outside the Great Lakes region. "It's our own laws that are going to keep us honest," Ramsay said. The province received applause from environmental groups. Robert Wright of the Sierra Legal Defence Fund congratulated the government for taking a "no diversions" stance rather than a position of "diversions with exceptions." "It is a victory for Ontario," Wright said, adding that while the agreement isn't perfect in protecting the Great Lakes for decades to come, "it is a good start."

Wright was particularly pleased that the deal allows for more scientific examination of Great Lakes water that will monitor and forecast its depletion from climate change and other factors. Without such agreements there's risks that resources such as water can be sold to the highest bidder without concern for the environment, said Sarah Miller of the Canadian Environmental Law Association. "While on the surface it seems to go without saying that we should be doing our best to protect 20 per cent of the world's fresh water, there are still those that feel bounty means no limits," she said.