BY BILL PHILLIPS
We’ve been up this creek before.
At 1:30 a.m. December 11, 2007 the City of Prince George declared a local state of emergency to deal with an ice jam on the Nechako River. Sections of River Road and Pulpmill Road were evacuated due to flooding.
Nine years, almost to the day, December 16, the city has once again declared a local state of emergency to deal with an ice jam on the Fraser River.
The 2007-08 ice jam was a phenomenon unlike anything seen in recent times. Then premier Gordon Campbell even came to the city to take a look.
While it started in December of 2007, the ice jam didn’t hit its full peak until 2008 and held an icy grip on the city that was trying to figure out how to deal with the problem. When cold weather set in at the end of 2007, the ice jam grew to 8.5 kilometres long, with the head of the jam reaching past the Foothills Bridge to the Riverview Road area.
Seven homes on the south side of Morning Place and one further west on North Nechako Road were delivered flood preparation information. The city got to work trying to clear debris and contemplated using gabion diking to keep back the water that being halted by the ice and overflowing the banks. Pumps were deployed to reduce ground water in some areas.
By New Year’s Eve 21 homes had been evacuated and the ice jam had reached Wilson Road.
Experts were trying to find a solution but many in the community felt blasting the ice jam would work.
The B.C. Ministry of Environment and independent experts, however, said that blasting or mechanically breaking up the jam would have no effect. The ice is a collection of “frazzle” or small pieces, not a single large blockage, and has nowhere to go because the Fraser is frozen.
There is little than can be done but mitigate the damage and hope for warm weather to melt the ice, they said.
And, of course, many felt something should have, or could have, been done prior to the ice jamming, such as dredging the Nechako River to make the channel deeper. Concerns about fish habitat, however, put the kibosh on that idea.
Two possible solutions were then acted on.
The first was to pipe water from the steam plant at nearby sawmill. The other project was to use an amphibious excavator to move ice from the Nechako into open water on the Fraser River. An Amphibex unit was brought in from Montreal, at a cost of $24,000 per day.
The Amphibex arrived by late January 2008 and, by then, the ice jam has extended past the city limits. The Amphibex went to work at the mouth of the Nechako, trying to open a channel. Huge amounts of ice that broke free in the Nechako River then jammed up near the CN rail bridge. The extreme cold had also closed the open channels in the Fraser River so ice from the Nechako River had nowhere to go.
The ever-increasing ice jam, which was more than 22 kilometres in length by the end of January, was proving tough for the Amphibex. One day the crew of the Amphibex had some tense moments as a large section of ice broke away and hit the machine. It was brought in on a 10-day contract and that contract wasn’t renewed. One of the problems was that it was breaking up ice, but the ice had nowhere to go.
The introduction of warm water into the Nechako River channel appeared to be having the desired effect on the ice jam at the confluence of the Nechako and Fraser rivers by the first week of February.
The system involved pumping water from the steam plant at Canfor’s Intercon pulp mill to the river’s edge, where it was mixed with colder water and the temperature lowered to just below 15 degrees C.
The system pumped about 9,000 gallons of the warm water into the channel per minute. The base of the jam, which extended several hundred metres into the Nechako channel from the confluence, was reduced by between 150 and 200 metres in a week.
At this time, the ice on the Nechako stretched 33 kilometres from its confluence with the Fraser to outside the city limits of Prince George. There was also an open channel extending seven kilometres from just downstream of the warm water pipe up to Stevens Drive.
Costs for both the response and recovery to the ice jam and flood were approaching $4.2 million by February. The majority of the costs incurred were for response activities undertaken since the ice jam and flood began on December 11, 2007.
Eventually the weather warmed up and the ice jam simply melted away.
In July of 2008, city council decided to permanently raise River Road to the 200-year flood level. The $7 million project was cost-shared with the city picking up half the cost and the Asia Pacific Gateway Corridor Initiative picking up the other half.
With the lessons learned from 2007-08 and River Road now serving as a dike, hopefully the ice jam of 2016-17 will be less costly.