An ice jam at the confluence of the Nechako and Fraser rivers has triggered a flood watch on the Nechako River.
B.C. regional flood hazard officer Lyle Larsen said the level of the Nechako River has risen over a metre in just two days this week. However, Larsen said, the river is not expected to overflow its banks.
"It started jamming [Wednesday] early afternoon," Larsen said Thursday. "By [Thursday] morning, the head the ice cover had extended up the Nechako up to the Hart Bridge."
Once the Fraser River freezes over, soft "frazzle ice" on the Nechako River has no place to go and starts piling up against the ice on the Fraser River forming an ice dam, he explained.
Frazzle ice forms on the Nechako River when temperatures drop well below freezing for an extended period of time.
However, he said, the amount of water flowing down river isn't large enough to threaten over-bank flooding.
Environment Canada's Isle Pierre monitor shows approximately 142 cubic metres of water of second is passing the station.
"Given the similar flows we've seen from the historic records, we would not anticipate over-bank flooding. When the water flow at Isle Pierre is about 200 cubic metres per second, we would expect over-bank flooding," Larsen said. "The water flow is about 100 cubic metres per second less than it was in 2007-08. The flood risk is would be moderate to low."
In 2007 and early 2008 a 64-day ice jam and flood on the Nechako River forced the evacuation of 24 homes, shut down businesses and caused millions of dollars in damage.
City of Prince George staff are monitoring the ice jam.
In addition, Cottonwood Island Park and parts of the Heritage River Trails from the Cameron Street Bridge to Fort George Park have been closed until further notice.
