A warm winter left the Fraser with a third less snowpack
Hydrologists say the shortfall will show up first in August flows, and again in the fall return.
The June snow survey confirmed what the ski hills already knew: the Fraser basin came out of winter carrying about two-thirds of its normal snowpack, the fourth-lowest reading in the survey's history.
Snowpack is the river system's savings account, drawn down through summer to keep flows and temperatures survivable after the rain stops. A third less snow means the drawdown starts earlier and ends sooner — hydrologists expect the deficit to surface first in August flows, exactly the weeks the sockeye are in the river.
The pattern behind the number is the more durable story. Total winter precipitation was close to normal; it simply fell warm. Mid-elevation stations recorded rain in January weeks that were snow in every decade of the record, and the freezing level averaged four hundred metres higher than the survey's baseline period.
What can be done with the information is mostly preparation: conservation orders drafted early, fish-water negotiations started in June instead of August, and the reservoir operators on the tributaries holding storage against the low-flow weeks. "We can't make it snow," the river forecast centre's lead said. "We can stop being surprised on schedule."
