The Great Lakes account for about 20 percent of the world’s surface freshwater and 84 percent of North America’s, and the region has extraordinary political clout this year, since it’s full of swing states that could determine the winner of the presidential race. This helps explain why Congress just passed the Great Lakes Compact, a major piece of legislation designed to guard the region’s ecosystems and increasingly coveted supplies of drinking water. Both major presidential candidates, for example, have repeatedly promised voters in states like Michigan to help protect the lakes.

But as noted by the Milwaukee Journal-Sentinel, the compact has at least one significant hole that will need to be monitored closely:

“Although the compact was designed to prohibit large-scale diversions of water outside the region, it does allow water to be exported if it leaves in containers that are 5.7 gallons or less. The provision will allow the region’s bottled water industry to continue to thrive, but [some critics worry] it could inadvertently open the door to large-scale water grabs.”

This is the potential pitfall of the new environmental politics in a region desperate for jobs. In the past, business leaders often tried to limit environmental protections, while advocates fought these businesses as the enemy; now they’re all at the table along with scientists and politicians. “Mandates don’t work, quite frankly,” Mayor Daley, a leading proponent of the cooperative approach to environmentalism, said last week, adding that it’s crucial for businesses to lead the way in greening the economy. This makes a lot of sense, but the problem with compromising natural resources is that it might be decades before it’s clear if the lines were drawn in the right place.

In this instance, there’s still a lot left of the lakes, but water levels are at historic lows, and shipping off even a 5.7-gallon jug of them will make a difference if you do it enough.