Chickens require clean drinking water, which may seem easy enough to do. But there are choices in how you deliver water to chickens and things to consider like frozen water dishes in the winter.
Learn about the various options for watering chickens and what watering system might work best for your laying flock or meat birds. Keep the water clean and palatable dirty water. That is too warm will sometimes cause chickens to stop drinking it. They also might not drink water that you've added something, like vinegar or vitamin powders. Make sure your chicken water is clean - scrub it with dish soap, hot water, and then a dilute bleach solution, then rinse well with plain, clean water regularly. Choose a type of water.
There are all kinds of chicken water and automatic systems that provide your birds with clean, fresh water constantly. You can use a round water that's made of plastic or galvanized steel which has a trough around the bottom with a shallow lip that the chickens drink from. The vacuum pressure allows just enough water to fill the lip constantly. These waterers work well.
They work best if they are elevated off the ground on a stand or hung from the rafters of the coop so that they don't get poop and shavings in them. There are also nipple systems that you can attach to the bottom of five-gallon buckets for a clean, gravity-fed system. You have to make sure nothing clogs the nipples, like minerals, and you have to train the chickens to use them. But small farmers are beginning to appreciate the cleanliness and ease of use of the nipple watering systems. Automatic waterers come in several different types.
You can use an automatic pet waterer, like a dog bowl style. These connect to a garden house. More traditional automatic chicken watering systems, like those used on larger farms, they are also available. Keep the water from freezing in winter if you live where the temperatures regularly get below freezing, you will need to either water the hens twice a day (bring a bowl of warm water out to them or fill waterers with warm water and allow all the birds can drink until they're full) or get a heated waterer. They sell metal heated waterer bases for the round metal waterers, or drop-in style heaters for a trough of water.
Chicken nipple drinker:http://www.jhfarming.com/for-chicken/drinker.html
Pig nipple drinker:http://www.jhfarming.com/for-pig/drinker.html