Snowmelt

The frozen reserve

In snow-fed basins the river you see in July fell as snow in January. We measure the snowpack all winter so the valley knows, in spring, exactly what's coming.

What we measure

SWE        snow water equivalent, the number that matters
depth      from stations and snow courses
satellite  basin-wide coverage, daily
melt       timing, and what it releases

Why it matters

Reservoir operators, farmers, and firefighters all bet on the melt. We make sure the number they're betting on is right.