Coquitlam Mayor Richard Stewart says he has a lot of hard questions for BC Hydro after underwater erosion downed a transmission tower and caused power lines between Surrey and Coquitlam to plunge into the Fraser River Monday night, choking traffic through Metro Vancouver and raising fears that river currents would pull power lines down onto Coquitlam roadways.
Chief among those questions, Mayor Stewart told The Tri-City News, is "how their line could have been undermined on the south side of the river for weeks and they had not reported it to the communities that would have been affected by this kind of calamity."
BC Hydro crews were forced to cut several transmission lines over Lougheed Highway, Highway 1, United Boulevard and the CN Rail tracks early Tuesday morning to relieve the stress on the system caused by the pull of the Fraser River on the downed lines between Surrey and Coquitlam.
Crews had cleared the lines from the roads by Tuesday afternoon but were still working to remove the de-energized lines from the river, according to a BC Hydro press release.
Hydro officials said Tuesday morning they had been aware for several days that river erosion had made some towers unstable and crews worked over the weekend to stabilize them.
BC Hydro vice-president David Lebeter is promising a full investigation and assessment of other towers along the river.
He told reporters the underwater scouring of the tower footings took engineers by surprise -they had been more concerned about a tower further upstream, not the one that actually fell.
Sagging power lines near the west end of the Port Mann Bridge and Cape Horn interchange forced the road closures and tension on lines splintered wooden power poles in some residential areas on the Surrey side of the river.
Lougheed Highway, Highway 1 and the eastern half of United Boulevard were reopened for the Tuesday morning commute but traffic was still at a crawl through the southwest Coquitlam area at 11 a.m., according to an eyewitness.
Mayor Stewart said he was first aware of a problem with the power grid as he was leaving Monday night's Coquitlam council meeting.
At approximately 9:30 p.m., the lights in the council chambers flickered twice, as they did all across the Metro Vancouver power grid, according to reports from as far afield as West Vancouver.
Mayor Stewart said that shortly after the flickering, he got a call from the Coquitlam fire chief Tony Delmonico.
"He told me essentially a line had collapsed into the Fraser River which was quite unbelievable and that the freeway and Lougheed Highway were having to be closed," Stewart said.
By 11 p.m. a makeshift command centre for RCMP, fire rescue and BC Hydro personnel had been set up at the United Boulevard Home Depot, not far from where a Coquitlam transmission tower closest to the Fraser River was bending south towards the water, its lines submerged.
"There was a very real risk that that first tower on our side [between Leeder Avenue and Burbidge Street] could have collapsed," Stewart said. He saw and heard first-hand the sideways stress on the tower as the flow of the Fraser pulled on the lines. "It was singing loudly. The metal was stressing and every indication was from the fire department and engineers that that tower could go and if it did, the stresses on the next tower would be tremendous and you could end up with a ripple effect as happened on the other side of the river."
Luckily, the tower held until 4 a.m. when the decision came out of the command centre to call in a bucket truck from Aldergrove to cut the lines over the roads.
"Our biggest concern was the collapse of thousands of pounds of overhead cable," Stewart said. "It was de-energized but it still would have killed people."
With all of the traffic delays and closures, it was after 5 a.m. before that truck arrived. But once it did, BC Hydro crews wasted no time in cutting down the stressed lines and beginning to clear them from the roads.
Mayor Stewart said that the southwest Coquitlam area has always been vulnerable to this type of power issue because of the cross-river connection, but called the Monday night incident "unfathomable."
"Last night, job one was to do everything we can to get the lines back open and remove the immediate hazard. But today I've got lots of questions and I've spoken with Mayor Watts in Surrey and we'll be coordinating together the search for the answers to those questions," Stewart said.
SFU geographer Jeremy Venditti said this year's Fraser flow has been the 10th highest on record but added it's been an extremely unusual freshet.
The river hit a high flow level of 10,000 cubic metres per second at Hope very early in the runoff season, he said, and it has kept running high for about five or six straight weeks due to the colder-than-normal spring.
"This is really the only time we've seen that in the last 100 years or so," Venditti said.
He said the long period of high water completely saturated the floodplain areas and weakened the soil, making the shoreline vulnerable to the formation of "scour holes" that can undercut the footings of critical infrastructure.
"It's very hard to predict exactly when the soil is going to become unstable," Venditti said. "Any small change in the flow patterns on the floodplain is likely to start a scour hole developing."
BC Hydro watcher Jim Quail, who tracks the utility for the BC Public Interest Advocacy Centre, said he's seen no sign under-investment might be to blame for the mishap or or any indication any towers had been flagged as vulnerable to river erosion.
"I've never heard of this happening," he said, suggesting it was a freak incident. "Their engineers are generally pretty conservative."
BC Hydro has long warned it's grappling with aging infrastructure and needs to raise rates to pay for the work, but that spending is mainly linked to dam upgrades.
Coquitlam city spokesperson Dan McDonald said that while power flickers and dimming were reported across Metro Vancouver as a result of the downed lines, there were no reports of outages here in Coquitlam. But, he said, "it goes to show you how these things can have an impact along a grid."
Some businesses along United Boulevard were closed Tuesday including Waste Management, whose garbage removal customers across the Lower Mainland were told that normal removal services would likely resume by today [Wednesday] beginning with Tuesday pick-up customers, as the company's trucks were unable to leave their lot due to road closures.
Because of the traffic congestion throughout the Tri-Cities as commuters tried to skirt around the southwest Coquitlam trouble spot Tuesday morning, the West Coast Express trains saw about a 10-15% increase in passenger volume heading into Vancouver.
TransLink spokesperson Drew Snider said that the increased volume did not require any adjustments to the service as the trains are usually only half full in either direction.
"We normally carry about 5,500 people a day in each direction and we can carry up to 10,000," he said.
Surrey Mayor Dianne Watts said she also wants to ensure proper emergency protocols are followed and determine what other towers may be at risk.
"It raises some serious concerns in terms of the stability of a number of those towers on the foreshore," she said. "Any time you have a transmission tower fall into the Fraser River there's got to be an assessment of the other towers in close proximity."
Watts noted the emergency also shut down the CN rail yard as well as shipping on the Fraser River.
-with files from Jeff Nagel
