How much water does one horse needed daily?

I have heard two different things. One said that they drink anywhere from 5 to 10 gallons a day. Another said they drink about 2% of their body weight a day. I don't know personally because my horses drink out of a pond. Supposing that you, like most people, feed your horses at least 2xs a day, I would think that if you had a 5 gallon bucket filled with water and you gave more water at each feeding, that should be enough.

A horse needs to keep hydrated like us,so we should keep a a bucket of water in their stable at all times but incase a horse/pony is working,none during a lesson.But is extremly important we give plenty of water after they have been working!