During the summer, it’s easy and convenient to regularly visit the barn or pasture. When the horses are in regular exercise, you’re paying close attention the water and feed they consume. Just remember that it’s even more important to monitor their water supply throughout the day in the winter months.
Horses expend water through the saliva needed to digest hay and feed, and a well-hydrated horse can better fend off hypothermia. Mature riding horses need as much as 10 gallons of water a day, if not more, than that amount. Without water, a horse can likely only survive for about three days.
Horses prefer water that is around 40 degrees F. Heated water troughs and/or automatic waterers are the least labor-intensive method of providing an ample supply of drinking water. Check the tank daily to make sure the heater isn’t shorting out and shocking the horse. Although the current is not likely high enough voltage to physically harm the horse, an electric shock is going to deter the horse from drinking out of that tub. And keep in mind that some horses are more sensitive to stray voltage than others. (Editor's note: We had a heated water tank where three of our four horses were drinking, but the fourth—an Arab mare—would not drink out of the tank. An electrician found that there was a small amount of stray voltage that was deterring her from drinking. After that was fixed, she drank alongside the other horses just fine.)
Consider investing in a generator. In the event of a power outage, barns relying on wells will not have water. Depending on the distance between the barn and the next available water supply could be too far to transport water daily.
If electrical service is not available for heaters or automatic waterers, it’s even more important to check the water supply throughout the day. Placing two or three five-gallon pails per horse in the pasture is another alternative. Once the buckets freeze, bring them into a headed garage to defrost or grab a hammer and knock the ice out. Buy enough buckets so that water is available while others are thawing.
In situations where streams and other natural water sources are the main means for providing water, plan on checking the source throughout the day and breaking any ice to allow horses access to flowing water.