Manitoba Hydro's decision to build a new transmission line on the west side of the province instead of the east is getting mixed reviews.

Manitoba Hydro's third high-voltage direct current transmission line — called BiPole III — will run west of Lake Manitoba, rather than cutting a shorter route through pristine boreal forest on the east side of Lake Winnipeg, officials announced Tuesday.

The western route is 50 per cent longer and will cost an estimated $400 million more to build. The extra resistance on the longer line will also cause more electricity to be lost, potentially costing Hydro millions more in sales .

But environmentalists have applauded the decision, saying that maintaining the untouched section of boreal forest is worth the cost.

"It's a good deal because of all of the services that Manitobans and Canadians get from intact boreal forest," said Gaile Whelan Enns with Manitoba Wildlands.

"If … you count and value all the ecological services that Manitobans receive and Canadians receive from all the intact waterways and rivers and forest lands on the east side, absolutely we'll get $500 million back in ecological services in no time."

Others aren't so sure the longer line is worth it, noting the extra cost works out to about $500 per Manitoban today, and cost estimates are sure to rise before the line is complete in 2017.

Adrienne Batra, Manitoba director for the Canadian Taxpayers Federation, worries about the risk Manitoba Hydro is taking with public money when potential returns from the transmission line could be decades away.

"Arbitrary decisions that they are making are putting Manitobans — you and I — on the hook for potentially a billion dollars in the future, and someone is going to have to pay for this," Batra said.

Premier Gary Doer brushed off concerns, saying export sales would pay for any additional cost, but Batra says export sales are a long way down the road.

"I have a very hard time believing that within the next 20 years, suddenly Hydro is going to be reaping multi-billion dollars in revenue to be paying off these debts," she said.

The new line will begin at Gillam, in northern Manitoba, run west of Winnipegosis and Lake Manitoba and end at a new converter station east of Winnipeg.

The precise route for the $2-billion line will be determined after an environmental, design and public consultation process that is expected to take several years.

About three-quarters of Manitoba Hydro's electricity production is currently supplied through two transmission lines that run from Gillam to Winnipeg through the Interlake area.

BiPole III will provide a back-up to those lines and carry power from new planned generating stations to southern Manitoba.