Question on Winter Watering

First year chicken keeper, and I have a question on how people water their chickens in the winter. I live in western Washington state so the temperatures are mostly mild in the winter (rarely below 25 degrees or so) which means the water will freeze.

What do people do to keep the water as a liquid for the chickens to drink?

Probably unnecessary information, but we have all Welsummers that are supposed to be hardy enough to withstand these temperatures so I'm not worried about heating the coop, just keeping the water as a liquid.

Thanks for any advice!