Water and hydration
Fresh, clean water available at all times. Horses will consume up to ten gallons per day per horse. They drink a lot of water at a time, a few times a day.
Cold and wind may create a skim of ice on otherwise acceptable water sources. Submersible tank heaters will keep water suitable for drinking in winter.
Horses need access to at least 10 gallons per day per horse of fresh water at moderate temperatures. they do not eat snow as a way of hydrating.