CAMPBELL RIVER, BC – Residents near the dam may have heard a loud explosion early on Friday morning.

BC Hydro spokesperson Stephen Watson says a contractor attached explosives to the base girders of one of the surge towers, which they detonated. The tower fell directionally as planned just some ways up from the old penstock corridor. 

BC Hydro had a 450-metre safety closure radios around the surge towers. This closed off the access roads into the site as well as the public trails around the area. 

Watson adds the utility’s contractor InPower BC and a subcontractor got a blast permit from the city. 

Before the blast, some of the tower’s supporting legs were cut using linear shape charges. Kicker charges were used to make sure the metal was fully separated and displaced.

Watson says crews are now removing the felled surge tower, with the steel to be recycled. Crews may fell the second surge tower next week. 

The third tower will stay.

“While not part of the new hydroelectric facilities, (it) is in good condition and will stay in place given it has communications equipment and is a visual aid to the local airport,” Watson said.

“There is also heritage value in keeping one tower in place.”

The towers stand at 90 metres and were the highest structures on Vancouver Island at some point. They operated from 1947 to 2018. 

The towers protected the penstocks from short-duration water pressure changes that happen when the water flow velocity is increased or decreased. 

The old John Hart facility was officially shut down last fall and replaced with a new underground hydroelectric facility.