Yakima farmers fight Seattleites over a lake near Snoqualmie Pass.

It’s September, so the hops harvest is in full swing in Washington state’s Yakima Valley. At the Carpenter family’s farm in Granger, workers make their way between rows of trellises, pulling down vines and feeding them into a sorting machine.

The Carpenter family has grown hops in the Yakima Valley since the 1860s. Brad Carpenter, who helps helm the operation these days, says farmers in a place as dry as this valley depend on one thing: water.

“Water’s everything,” Carpenter says. “Without water, you’re not going to see anything out here but sagebrush” — and certainly not the apples, cherries, pears, and hops that contribute billions to Washington’s economy.

Here’s the problem: Most of the water that Yakima farmers use on their crops comes from the snowpack that builds each winter in the Cascade Mountains and then melts slowly through the spring and summer. And scientists say, with climate change making winters warmer, the snowpack is expected to shrink.

That has KUOW listener Bob Hiltner worried. He asked KUOW's SoundQs team to look into what water sources could replace the diminishing snowpack.

It turns out Yakima’s farmers are asking the same question, and they’ve set their sights on Lake Kachess, one of the finger lakes just off I-90 near Snoqualmie Pass. (Lake Kachess or Kachess Lake, same difference, but all agree it rhymes with "peace.")

To explain why they need a backup water source, farmers will talk about 2015. That year, the snowpack was less than a quarter than what it is normally. Brad Carpenter remembers: His farm was without water for three weeks.