Since David Lewis has had his cottage in the Fishing Islands on the Bruce Peninsula, he's seen the lake water levels drop drastically.

Wayne Grady (Armina Ligaya/CBC)

Judging by the lines on the shed he normally docks his boat in, he says Lake Huron has gone down about 1.5 metres in the last 10 years. Now, some of the islands are no longer islands.

"The water used to be up to your shoulders. Now, you can drive up to the island from the mainland," said Lewis, who has lived in the region since 1972.

He isn't imagining things.

In fact, water levels in all the Great Lakes are down a half-metre — the biggest drop ever, according to science writer Wayne Grady, who has just written The Great Lakes: The Natural History of a Changing Region.

"This is the first time that all five lakes are all down about the same amount," he said in an interview. "That's the scary thing, and it all just happened almost overnight."

The water — which represents about 20 per cent of the world's freshwater supply — is evaporating at a faster rate due to global warming, he says. Although the Great Lake levels fluctuate on a cycle, every six to seven years, the water is one-half metre below those projections.

Scientists had predicted that by mid-century the majestic lakes' water levels will drop 1.5 metres, said Grady. He expects those estimates to be bumped up as this year's drop puts us further ahead of schedule.

Grady, who spent three years researching and writing his book, believes we're at a crucial tipping point. There aren't enough measures in place now to protect Canada's landmark water reserves or to reduce greenhouse gases, he says.

And while climate change has been a cause celebre this year, Canadians aren't aware of how close to home it's already hit, he says.

"People haven't been connecting those things with the Great Lakes and with our water supply. And now that globally, water is becoming a huge issue, people are starting to realize that we've got this precious resource here. And if we're not careful with it, we're going to lose it."

Clear liquid gold

When it comes to water, Canada is one of the world's more fortunate nations.

"Over a billion people live without access to fresh drinking water," Grady says. "We have a glut of fresh water. In the next couple of decades as global warming continues to desertify areas, many people are going to be eyeing the lakes."

It's not a new concept. Attempts in the past to divert water, or export bottles for profit, have been mired in controversy.

One such proposal was in 1986, when the U.S. Army Corps of Engineers came out with a plan to build a pipeline somewhere in Duluth, Minn., to pump water from Lake Superior. The water would travel through South Dakota and eventually find its way to the Mississippi River to quench the farms on the Great Plains.

The plan was approved by all governments involved. But it was eventually dropped once USACE realized it needed to build seven power plants along the way to generate enough energy for the operation.

"The plan was scrapped," Grady says. "But, my point is, it was scrapped for economic reasons and not for common sense reasons or nationalistic reasons. Or any reasons that would make us feel good about it."

Then there was the Grand Canal scheme. The plan was to install a dike across the top of James Bay, blocking out the salt water and turning it into a freshwater lake. Then, salt water would be pumped out of James Bay and into lakes Superior and Huron. It was approved by Robert Bourassa, then premier of Quebec. However, the project was dropped, again, because of a steep financial tab.

However, one project, called "the Chicago diversion” has been legally siphoning massive amounts of water from Lake Michigan since 1948. That water isn't being returned to the Great Lakes, rather, Chicago drains it into the Mississippi.

A similar project could be in the works to replenish the Ogallala Aquifer in the American midwest, says Lino Grima, a semi-retired professor at the University of Toronto's Centre for the Environment. This large, underground water source has been used for more than a century to quench farms.

"The Ogallalla Aquifer produces water for 20 per cent of the agricultural products in the United States. And it's getting depleted," Grima says. "Sooner or later somebody will look north and put in a very big straw to drink Canada dry."

Legal protection

What can Canadians do to stop these diversion projects? There are legislations in place, such as Bill C6 and Bill 198, but the laws aren't water-tight.

Bill C6, which received royal assent in 2001, prohibits bulk exports of water from the Great Lakes. However, the term "bulk export" is loosely defined, says Grady.

"Is a tanker full of water considered a bulk export? Is a bottle considered a bulk export? If you take a million bottles, it's possible for each one not to be a 'bulk export,'" Grady says.

The Department of Foreign Affairs and International Trade defines a bulk water export as anything over 50,000 litres.

"The fear is someone can come in, bottle 49,000 litres worth of water, not call it a 'bulk export' and get away with it," Grady says.

Bill 198, also called the Safeguarding and Sustaining Ontario's Water Act, which was tabled in April 2007 by the Ontario government, is intended to prevent water from being guzzled or diverted. It would also make into law a June 2005 pact between all eight Great Lakes states and Quebec that aims to restrict large-scale diversion of water from the lakes.

One of the main problems in implementing rock-solid legislation to protect the lakes is the number of institutions that need to be involved. That includes two federal governments, eight state governments, two provincial governments and hundreds of municipal governments, Grima says.

"Getting these institutions organized to do the right thing is a big process. It takes years just to get them talking to each other," he says.