VICTORIA -- The British Columbia government is pushing ahead with the controversial $8.5 billion Site C hydroelectric dam on the Peace River in the province's northeast.

Premier Christy Clark said Tuesday her government arrived at the decision after very careful analysis.

"It was not an easy decision to come to. In order for our economy to grow, we need to ensure there is power."

Clark said the dam will bring clean, reliable and affordable power to the province.

While the province is the leader in North American in energy conservation, Clark said that doesn't eliminate the need for new energy.

"Is going to benefit British Columbians for generations," she told a crowd in Victoria.

Energy and Mines Minister Bill Bennett said the decision to go ahead with the project is what's best for ratepayers and what's best for B.C.

The dam would be the third on the Peace River, flooding 5,550 hectares of land over an 83-kilometre stretch of valley and it ranks as B.C.'s most expensive public project.

Bennett said he doesn't expect First Nations to publicly endorse Site C, but he was hopeful benefit agreements could be negotiated. He said First Nations companies and people could profit greatly from the project through construction contracts and jobs.

Last fall, some First Nations in northeast B.C. issued the government an ultimatum, saying it must decide between developing the liquefied natural gas industry or Site C. They can't have both, they said.

The proposed dam is located in the heart of the province's natural gas fields, where drilling will occur and pipelines to B.C. northwest will be built.

A recent letter sent by the Treaty 8 Tribal Association in Fort St. John to Bennett and Finance Minister Mike de Jong said the First Nation is convinced Site C is not the most economic alternative and "involves unacceptable and unnecessary risks."

The association also sent along a consultants report it commissioned that said there would be no need for new electricity resources in B.C. until 2027 if other resources methods were used.

The project has been undergoing public reviews and consultations with First Nations, communities and stakeholders since 2007.

The Crown Owned BC Hydro said it reached a major milestone recently when it received federal and provincial environmental certificates -- as long as more than 80 conditions are met before it proceeds.

Last spring's joint review panel report weighing the project found the dam would cause significant adverse effects on the environment and wildlife, as well as aboriginals, farmers and other users of the Peace River valley.

But the benefits are clear and the alternatives, few, the panel appointed by the Canadian Environmental Assessment Authority said in its 471-page report.

The panel gave no clear yes or no answer, but said B.C. will need new energy and new capacity at some point. The dam on the Peace River would provide a large amount of inexpensive power, low in greenhouse gas emissions, it said.

BC Hydro's environmental impact report issued last year concluded a diverse range of wildlife species, including birds, bats, butterflies and fish destined to suffer habitat destruction from Site C, but the utility has plans to reduce and prevent harm to area wildlife and ecosystems.

Among Hydro's measures to reduce the potential loss from its proposed project are special protective crossings for amphibians, slower turning turbines that allow fish escapes and fish-free wetlands to permit safer breeding for dragonflies.

Hydro identified in its environmental impact statement what it called 22 valued components that are expected to undergo some level of change due to the project. They include agriculture, transportation, outdoor recreation and tourism, air quality, noise and vibration, heritage resources and human health.

The environmental impact statement also forecasts flooding more than 5,000 hectares of land, of which at least 3,800 hectares is agricultural land. The project will also flood First Nations heritage sites and force up to 20 families -- many life-long ranchers -- to move.