When storing drinking water in reservoirs for grazing animals (livestock and wildlife), dependability of the facility is critical. Often, however, when the water is needed most, the reservoir is dry. According to Stoddart and Smith (1955), “Its disadvantage lies in the fact that it depends upon surface runoff or seepage and may be empty when most needed, as in the time of drought or in dry seasons of the year.” Recognizing the above statement as being accurate, the author of this paper does not recommend reservoirs as a source of water over springs and wells, which are consistently more reliable. However, on lands inhabited by grazing animals where springs and wells are absent, a reservoir can still be a viable source of water if properly located, designed, and constructed.