A $1-billion hydroelectric project proposed for the Slave River will not go ahead, after proponents couldn't reach an agreement with a First Nation in Fort Smith, N.W.T.

Alberta-based ATCO and TransCanada were working on the proposal, but their efforts to reach an agreement with the Smith's Landing First Nation on feasibility studies came to a halt last week.

During a meeting with officials from both companies, Smith's Landing Chief Cheyeanne Paulette announced he opposes a dam on the Slave River, citing environmental concerns.

"We were very close to an agreement with them," Doug Tenney, ATCO's vice-president of hydro development, told CBC News.

"They'll probably have a different take on this, but I believed that we had reached an agreement with their negotiating team, so we were now at chief and council as to whether they wanted to ratify the agreement."

While a proposal to build a dam on the Slave River has existed since the late 1970s, ATCO and TransCanada began their own attempt in 2006, in the hopes of selling the electricity to customers in Alberta.

Tenney said had the First Nation agreed to a feasibility study, the research would have determined exactly how large the hydroelectric project would have been.

"We don't have a specific capital estimate in mind because we don't have the size of the project, but I'd think you would be correct in stating that it would be in the billions," he said.

Tenney said their proposed hydroelectric facility would have allowed water to flow through it and would not have created the huge reservoirs associated with traditional dams.

However, some reserve land belonging to the Smith Landing First Nation would have been flooded, forcing some of its members to move.

Paulette said his First Nation's members have had to relocate once before because of another dam project near Fort Fitzgerald.

"There was a lot of heartache a lot of negativity that happened when the government forced Smith's Landing to move from Fort [Fitzgerald] to Fort Smith, so people did not want to experience that move again," he told CBC News on Monday.

Officials with ATCO said while the project is done for now, it hopes to revisit the idea in five or 10 years.