By Laura Keil
On Wed. June 22nd, the Village of Valemount warned the public about rising waters levels in Swift Creek, urging them to stay away from the water, as communities across the province brace for high water and potential flooding.
“There is the potential for bank erosion, instability and increased turbidity,” the Village notice said of Swift Creek, the source of the Village’s drinking water. “The Village of Valemount water system is currently operating as it should; however, there is the potential for water restrictions to be increased beyond the current Stage 1 level. Please avoid all streams and water bodies with rising levels.”
A special weather statement issued by Environment Canada said elevated temperatures will lead to an increase in snowmelt and snowpack instability at the end of June. Temperatures were expected to return to near-normal values by June 29th, but rivers in many areas of the province have high flows due to runoff from the melting snowpack and ongoing precipitation.
The BC River Forecast Centre said the delay in the melt leaves rivers vulnerable to flooding, particularly over the next couple weeks.
“Current weather forecasts show temperatures to increase to above seasonal levels across the province from June 24-27th. After this brief warming event, temperatures return to seasonal levels with the possibility of heavy precipitation for the central and eastern interior.”
The River Forecast Centre said advisory levels can shift quickly.
The Forecast centre says the June 15th Snow Basin Indices (ie. snowpack size) for BC show an increase since June 1st due to colder than normal weather and a delay in the onset of melting for high elevation locations. For June 15th, the overall provincial Snow Basin Index was at 198 per cent of normal. The Centre said this year’s snow melt has been delayed by 2-4 weeks, with over half of the seasonal snowpack now melted. High snowpacks increase seasonal flood risk.
“Large rivers across BC are currently flowing at or near seasonal peak levels due to contributions from the melting snowpack and wet weather. Flows may experience further increases with the upcoming warm weather.”
The Centre said the systems most at risk from the upcoming heat and precipitation are the North Thompson, South Thompson, Thompson, Shuswap, Columbia, Kootenay and Fraser River. “Prolonged high flows are expected to extend into July this year.”
As of June 27th, there was a flood warning in effect for the Quesnel River; a Flood Watch in effect for the Thompson River, South Thompson; and a High Streamflow Advisory in effect for the North Thompson.
The public is advised to stay clear of the fast-flowing rivers and potentially unstable riverbanks during the high-streamflow period. A High Streamflow Advisory means that river levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible. A Flood Watch means that river levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur. A Flood Warning means that river levels have exceeded bankfull or will exceed bankfull imminently, and that flooding of areas adjacent to the rivers affected will result.