It depends on the size, bred, amount of work they're doing and how hot it is. Typically they need at least 15 gallons a day.
Horses can drink up to 70 liters of water per day. The amount of water that a horse actually NEEDS to survive will depend on its circumstances (temperature, type of horse, size of horse, amount of work, etc.)
Horses should always have water in their buckets at all times. As for food, well, that depends on the horse's size, diets, workload, and many other things.
Clean and Cold water should always be available but usually they need 5 to 10 Gallons.
A horse that can swim
Yes. Water is necessary for many aspects of your horse's health. It helps to flush impurities out through the kidneys, helps the nutrients from food get where they need to go, lubricates joints and protects body organs, helps regulate the horse's body heat, and many other things. No horse should EVER be left without access to clean fresh water. But when a horse is engaged in hard work, you will need to regulate how fast the horse is drinking water, and how much. Too much too fast after hard work can cause colic or laminitis. Allow the horse to cool down first before allowing it to drink large amounts of water.
This is highly dependent on breed, weight, type of work, air temp/humidity, salinity of feed, etc. Thus there is no definite answer, especially in terms of actual volume, of the amount of water that a horse needs.
You will need approximately 1 acre to 1.5 acres of land for each horse you own in New York. You should not only look at its area, its quality and the water supply.
you need a whip and some water and thats all
water and horse food and a shelter
It depends on the horse, but every horse should be worked for at least an hour or more
no if the horse comes up to breathe from above the water than no
if it is dusty and/or your horse has an allergy than yes