Battle brewing over colour-shifting lake

September 2, 2004

A fight is shaping up in the Interlake over a spectacular, colour-shifting lake that sits on top of a promising nickel deposit.

A world-renowned geologist wants Little Limestone Lake north of Grand Rapids included in a new national park scheduled to be created next year.

Derek Ford and the Canadian Parks and Wilderness Society are launching a campaign to persuade governments to change the park’s boundaries to protect the lake from mining they believe could destroy the ecotourist jewel.

But high-quality mineral deposits under the lake could eventually spur development of a new mine that would help northern Manitoba weather the depletion of Thompson’s nickel reserves.

A First Nation with a reserve along the lake’s shore is open to working with Falconbridge on that project.

The colour of Little Limestone Lake alters from chalky blue to turquoise to emerald green depending on the temperature, as dissolved lime precipitates out of the lake. Ford, a retired geology professor from Hamilton who is a world authority on the limestone terrain known as karst, has been lobbying since 1997 to have the remarkable lake included in a park proposed for the Manitoba Lowlands.

The final decision rests with the province, which has jurisdiction over mining and is working with Parks Canada on plans for the lowlands park.

Ford visited Little Limestone Lake, 70 kilometres north of Grand Rapids, this week as governments prepare to launch public consultations on the proposed park.

“It has been the most spectacular blue I’ve ever seen in an inland lake anywhere in the world,” Ford said of his previous visits in the early 1980s. “If you want to see a comparable blue, you go to the Bahamas Banks.”

Ford has been instrumental in getting other Canadian natural areas, including Nahanni National Park, designated as world heritage sites, but he said further study would be required before he made a recommendation on international status for Little Limestone Lake.

Few Manitobans have seen the lake, which is easily accessible off Highway 6 on the drive from Winnipeg to Thompson. On Tuesday, the 15-kilometre-long lake was a milky turquoise that shifted to green as sun and clouds played over the surface. The morning air was not quite warm enough to continue the chemical reaction that releases carbon dioxide from the dolomite dissolved in the lake, leaving behind tiny suspended particles of white calcium carbonate.

Ford said the process is like boiling well water in a kettle, leaving behind a film of lime.

The reaction only occurs in “marl” lakes fed by water running through dolomite or limestone. Little Limestone Lake has the highest density of suspended particles of any large marl lake, probably because it is so shallow that it warms up quickly.

Ford said Ireland’s famous marl lakes are “feeble” in comparison.

“We knew it was special, but we didn’t know it was that special,” said Roger Turenne of the Canadian Parks and Wilderness Society.

Peyto Lake in Banff National Park has a similar look, but the suspended particles are created by a different process.

The province and Parks Canada agreed this spring on tentative boundaries for a new national park with two separate segments north and south of Grand Rapids. It would be the third, and probably final, major national park in the province, after Riding Mountain and Wapusk near Churchill.

The proposed boundary runs along Highway 6, but Little Limestone Lake is directly across the highway in an area known as the Thompson nickel belt, identified by the mining industry as having high mineral potential.

The provincial government excluded the lake from park discussions during the Filmon years. “The government decided it wanted new parks—and mines,” said Jamie Robertson, director of North American exploration for Falconbridge, one of Canada’s biggest nickel-mining companies.

The company has staked claims in the area and hopes to continue exploration work near Little Limestone Lake the winter after next. About 120 metres under the lake is believed to be nickel similar to that found in Thompson.

The mining company does not know yet whether there is enough nickel in the area for a commercially viable mine. A compromise that might be acceptable to some environmentalists would give the company a deadline to complete exploration and make a decision on whether to proceed with a mine. But Robertson said technology continues to change, meaning something that might not be viable this decade could be profitable in the future.

He said a new mine would not necessarily disturb the lake, even if nickel is extracted directly under it.

But Ford said a mine could ruin the lake by pumping water into it or leaving tailings nearby that leak through the dolomite riddled with small channels.

“Tailing ponds in a limestone region are very bad news indeed,” he said.

Even mining exploration could rip up the wilderness around the lake and threaten the water, environmentalists fear.

Turenne, who calls Little Limestone Lake the “missing piece” in the proposed national park, said marl ponds are not uncommon, but large marl lakes are more scarce than nickel.

Manitoba Conservation Minister Stan Struthers said the government is “open to all suggestions” on the new national park, but he will not take a position on Little Limestone Lake until after this fall’s consultations. The eastern shore of the lake is reserve land belonging to the Mosakahiken Cree Nation, whose members live at Moose Lake.

Coun. Abel Martin said the First Nation wants to set up its own resort at the lake known for great walleye and pike fishing, rather than include it in a national park. Parks Canada spokeswoman Marilyn Peckett said a campground or cultural interpretation centre run by the First Nation could tie into park programming.

Martin said the lake used to be known as Kaskishika Lake. He said the Cree used to boil rocks at the lake, possibly to make paint.

Gaile Whelan Enns, director of Manitoba Wildlands, said a fight with the mining sector over Little Limestone Lake might detract from the touchy process of getting everyone on side to establish the national park.

After a dozen years of discussions, some key local communities oppose the park, while the mining and forestry industries are unhappy with some of the proposed boundaries.

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