If any of the three dams, which would divert water south to a hydro plant at the mouth of the Barnston River, aren't approved, it has a back-up proposal for another dam and powerhouse near the mouth of the Hoarfrost River at the end of the East Arm.

Glacier is eyeing future diamond mines in the Lac de Gras area, though potential electricity customers have yet to emerge.

On June 12, the Alberta-based power company applied to the NWT Water Board to pump water from MacKay Lake through a series of water courses on the Barnston River system to a dam at the mouth of the river in McLeod Bay.

A week later, Glacier Power filed another application, this time for a dam and power plant near the mouth of the Hoarfrost.

The first application outlines three power plants -- Barnston 1, 2 and 3. The highest dam at the head reservoir raises water levels about 10 metres.

The Hoarfrost powerhouse would be 270 kilometres east of Yellowknife and require six kilometres of canals, two dams and a tunnel.

The power plants are intended to serve three identified loads in the Lac de Gras area, according to the application.

BHP Diamonds expects to complete construction of its diamond mine in the area next year, while Aber Resources and Kennecott Canada have proposed a second mine for the region.

None of the mining companies, however, has expressed an interest in buying electricity from Glacier's proposed dams, according to Glacier president Doug Main.

"There's no new information on financing or mine sites (that might be interested) -- nothing there right now," he said.

"We found out about it along with everybody else," said BHP spokesman Graham Nicolls.

"We're building our own (diesel) power plant at the site. We have to -- there's no alternative. That's not to say there might not be a proposal or project we might take in the future," he said.

Nicolls called the Glacier project "hypothetical," but suggested BHP might be interested in the future, depending on fuel costs. But in the meantime, he said, "we would still have to maintain diesel at the site for backup."

BHP needs the diesel power plant completed by the fall of 1998, he said.

The Hoarfrost dam would be 45 metres high by 170 metres wide, raising the water level 40 metres.

"It's a very narrow, long valley that it's in and that high dam was necessary in order to get sufficient drop for the power plant," says Glacier's Main.

"I would really not choose to build the Hoarfrost, it's really meant as an alternative," says Main.

"The intention is not to proceed with that facility (Hoarfrost) immediately. We would not proceed with any environmental work unless we perceive there's a problem with the Barnston project."

According to the application, the Hoarfrost plant would replace any one of the Barnston plants if one is rejected. Also, the Hoarfrost would be in addition to the three Barnston power plants if the Lac de Gras load additions are significantly higher than anticipated.

The plant would reduce greenhouse gases by 1.4 million tonnes and thousands of tonnes of carbon monoxide, sulphur dioxide, nitrous oxides and other emissions during its first 25 years of operation, according to the application.

However, flooding associated with the dams produces other environmental effects, including possible contamination of the wildlife by toxic mercury leached from the soil.

"It has happened in other hydro projects and it should be a concern with this one," said Kevin O'Reilly of the Canadian Arctic Resources Committee in Yellowknife.

The proposals also call for altering the watersheds and a 350-kilometre corridor from the powerhouse to the Lac de Gras area.

Glacier has asked the water board for a 25-year water licence for the Hoarfrost project.

Bill Braden of the NWT Power Corporation described it as "a bold plan like the whole diamond venture -- big in scale and scope."

"We're interested in the approach. We're also considering our response to the water board, Braden said. The board has asked for responses by July 4, he added.

There is one residence at the mouth of the Hoarfrost River, about 500 metres from the proposed powerhouse. Pilot and author Dave Olesen has lived year-round at the cabin since 1990, and no other people winter nearby, according to the application.

Regulatory approvals and environmental studies should take a year, detailed design a year, and procurement and construction another two.

The proposal must also undergo an environmental screening by the Department of Indian and Northern Affairs before it makes it to the water board.