BC Hydro has seen a major spike in the cost of a massive power project in northern B.C. 

The price tag for the Northwest Transmission Line is now set to top $700 million, up more than $150 million from the estimated cost released this spring. 

BC Hydro vice president Bruce Barrett says one reason for the increase is the cost of bringing in labour and equipment from all over the province, largely because the project is competing with other industries for workers. 

"When the project was first planned six years ago, the forest industry was down, the level of activity was down, people were moving away. Now the area is just so active," he said.

"We've had to bring in labour and equipment from throughout B.C. to get the work done and its driven up the costs quite considerably."

Barrett says challenges around clearing the remote terrain have also added to the costs.

"We have found that clearing the forest and building the roads has significantly exceeded our initial cost estimates," he said.

The 344-kilometre power line would run from a substation south of Terrace to Bob Quinn Lake on Highway 37. 

The project is expected to be finished by the spring of 2014.