An unseasonably high snow pack and impending warm spring rains raises river levels and fears of flooding in the back country. Silvicultural crews warned by Provential Emergency Program to be vigilant.
22 May 2002 Western Silvicultural Contractors’ Association Weather and flood warning for silvicultural crews.
An unusually high seasonal snowpack in parts of the province and the advent of intense spring rain storms has prompted the Provincial Emergency Program to issue weather and flood warnings for silvicultural crews across British Columbia and parts of Alberta. Although the weather dependent hazard can shift almost on an hourly basis the main risk areas today are in the East Kootenay, the Pine Pass area north of Prince George, and the Cariboo Mountains near Quesnel Lake. Treeplanting and forestry crews are active in all these areas.
Over the last few days parts of the East Kootenay have recorded the most rainfall seen in years. This warm rain, the result of a large storm cell moving in from the south, has been concentrated largely east of the Rocky Mountain Trench. Although snowpack levels in this region are normal or near normal for this time of year the combination of wet precipitation and snowmelt poses a threat of washouts, flooding and slides throughout the south east corner of B.C. and into Alberta. The Bull River and Elk Valley drainages and the Kimberley area are particularly threatened. Some of the immediate risk has been mitigated by a cooling at upper levels turning rain to snow. However, this snowfall will likely melt soon as the front moves into Montana later today only stalling the hazard momentarily.
Almost from a west-east line through Williams Lake north snowpack levels remain unseasonably high. Some areas report levels twice the seasonal norm. These dense and increasingly damp accumulations, which are at near record levels, need only the catalyst of wet rain and warmer temperatures to release huge pent up flows into watersheds. Many rivers across the region are already at flood levels.
Twelve years ago this June five treeplanters died in the Bowron watershed when their van drove off a washed-out bridge span at night. Many of the same circumstances that created that tragedy are present today and government officials are anxious to avoid repeating the same calamity a decade later. Last year in July treeplanters had to be rescued from an island when the river they were camped on near Tumbler Ridge suddenly swelled beyond its banks during a series of severe summer storms.
Since flooding can take place in a matter of hours and debris torrents can take out bridge spans in a blink contractors need to locate camps well away from potential flood hazards. Driving, particularly at night, during this time should include stopping at bridge crossings and ensuring spans are present and in good shape. Do not assume all culverts are in place either.
As the hazard grows and shifts with spring inevitably bound to bring warming government will provide updates pin pointing areas of high risk. Nevertheless all contractors need to be generally vigilant on behalf of their crews and their families. In the meantime every day of delayed snowmelt only increases the amount that must run off later.