One of the primary limitations to developing and implementing a rotational grazing system is water - especially during times of drought. During the summer months, it is quite common for an animal to consume 2 percent of its body weight in gallons. In other words, a 1,000-pound cow will drink 20 gallons of water per day, while a 500-pound calf will drink 10 gallons. Therefore, a herd of 100 cows and their calves will require a minimum of 3,000 gallons per day in August. And remember, most of your cows weigh more than 1,000 pounds.
It would also be wise to have a three-day supply of water on hand at any time just in case something does not go the way you plan. This means you need 9,000 gallons of water on hand at any time for 100 cows plus their calves. Table 1 provides you with information on storage capacity.
This information may not apply if you have unlimited water from a pond, creek or electric submersible pump. But if you depend on a windmill or solar pump, this information will be critical to your operation.
A windmill pumping at 2 gallons per minute will provide 2,880 gallons per day if the wind keeps blowing. A typical solar unit will pump around 5 to 7 gallons per minute during moderate to peak sunlight hours - about eight hours during the summer months - providing 2,400 to 3,360 gallons per day. Solar pumps can also be connected to a generator and pumped even when the sun doesn't shine.
An over ow pond for a solar unit
Over the past several years, I have worked to replace our windmills with solar units because it has become very difficult to find anyone able or equipped to work on windmills. Something else I attempt to do is pipe the overflow into a small pond for additional storage.
If an overflow pond is not an option, aboveground storage might be the solution to your problem. Storage tanks will cost you up to $1 per gallon of storage to put in place. Table 2 can be used as a quick reference for storage capacity.
You may be able to obtain financial assistance for water development. The Natural Resources Conservation Service and Farm Service Agency often have cost share programs available, especially during times of drought.