The risk of potential flooding from the spring snowmelt remains low for Kamloops, and is slightly higher for areas downstream of Kamloops Lake.
New data released today by the BC River Forecast Centre shows that as of April 1, the snowpack for the Lower Thompson is 22 per cent above normal, which represents a potential flood risk once alpine snow starts to melt.
The Lower Thompson includes rivers and streams that feed into the Thompson River downstream of Kamloops Lake.
Meanwhile, the North Thompson snowpack is at three per cent above normal and the South Thompson snowpack is right at normal levels for this time of year.
That is a significant change from April of 2020, when the North and South Thompson snowpacks were at their highest levels since 1999. A prolonged snowmelt and a wet spring and early summer led to high waters on the Thompson River and flood protection measures being in place until late July.
The snowpack for the Nicola, meanwhile, is eight per cent above normal, which is relatively close to normal conditions.
“By early April, nearly 95 per cent of the annual B.C. snowpack has typically accumulated. Peak provincial snowpack usually occurs in mid-April,” the snowpack bulletin says.
The BC River Forecast Centre expects the spring freshet, or spring snowmelt, to start next week at lower elevations, with temperature highs expected to be 20 degrees Celsius for Wednesday and 22 degrees for Thursday. The forecast centre says this will lead to a rise in streamflows in smaller creeks, in particular.
While snowpack is one risk factor for freshet flooding, snowpack alone cannot predict whether flooding will occur or not. Spring weather is also critical, where the timing and severity of temperature and rainfall patterns are important drivers of flooding irrespective of snowpack.”
Across B.C., the average alpine snowpack is 12 per cent above normal, compared to 14 per cent above normal as of March 1.
The flood risk is significantly higher in parts of coastal B.C. and the South Coast; as of April 1, the highest snowpack values in B.C. were in the Northwest at 200 per cent of normal, the Central Coast at 145 per cent. The snowpack is also at 132 per cent of normal for the Upper Fraser West, for areas north and west of Prince George.
