Bridges, power transmission lines and other infrastructure along the Fraser River serving Metro Vancouver could be at risk if seven derelict ships moored at Mission are pulled loose by flood waters and swept downstream.
B.C.'s Environment Minister Terry Lake intervened Tuesday, issuing an emergency declaration to use special powers to deal with the improperly secured vessels, which include the former Queen of Sidney ferry.
A marine expert determined the vessels are at risk of breaking free of their moorings due to their poor condition, high river flows and flood debris that could put more strain on mooring lines.
According to the ministry, the vessels could threaten downstream river traffic, houseboat residents and critical infrastructure, including rail and highway bridges and other utilities alongside or crossing the Fraser.
"We're looking at an increased level of risk," environmental emergency response officer Ken Meeks said.
He said the one-in-40-year flood underway, the heavy debris already moving downstream and the additional vessels all tethered to the Queen of Sidney make the situation more dangerous than in past years.
The seven vessels together weigh more than 7,000 tonnes, he said.
They also pose an environmental risk from the potential presence of hazardous materials, physical damage to downstream habitat and the risk of secondary spills if one of the derelict ships hit another vessel in the river.
As of Wednesday afternoon, the province was preparing to select contractors to help secure the vessels, and to potentially arrange 24-hour monitoring of the site.
"We're trying to choose the best option available to us without complicating the situation, making it worse and putting the people who would be doing the work at risk," Meeks said.
Transport Canada may also commission a tug boat to be in position to respond, he said.
River Forecast Centre head Dave Campbell said the Fraser River is expected to peak at Hope late Thursday or early Friday at a level perhaps 10 or 15 centimetres lower than the previous peak last weekend.
Meeks said the province aims to recover costs of the emergency response from the responsible property owners, who have been identified.
The region has seen key infrastructure fail before due to high water on the Fraser.
Last summer, a BC Hydro transmission tower between Surrey and Coquitlam fell into the river, causing extensive power outages and forcing the closure of the Port Mann Bridge and other roads where high-voltage lines dangled dangerously close to cars.
BC Hydro spokesman Greg Alexis said there appear to be no problems with the towers along that section of the river, but added inspections have been stepped up.
A 500-kilovolt line tower that was leaning last summer after its footings were threatened by freshet erosion has since been stabilized.