May stream flows in Montana this year reached “once-in-a-lifetime” highs in many locations washing out 52 records and filling reservoirs heading into the summer growing season.

“This year will stand out in history as one of the biggest years on record for purely snowmelt-driven flows in rivers across the state,” said Lucas Zukiewicz, a water supply specialist for the U.S. Department of Agriculture’s Natural Resources Conservation Service.

That makes 2018 unlike other big peak water years in 1964 and 1975 when significant rain events combined with snowmelt to fuel high flows and flooding, Zukiewicz said.

Snowmelt alone drove the high flows this year.

The Clark Fork River above Missoula stood out.

It reached 33,250 cubic feet per second (cfs), the highest flow recorded since the river reached 48,000 cfs on June 1, 1908.

“It’s a once-in-a-lifetime event potentially we’re seeing across the state this year,” Zukiewicz said.

    – Great Falls Tribune