Swimming pools, decorative ponds, fountains and waterfalls can consume high volumes of water through evaporation. The amount of evaporation is related to outside temperatures, wind velocity and other factors. For example, in Phoenix and Tucson, the average evaporation rate is approximately six feet per year, most of which occurs in summer. Other sources of water loss in addition to evaporation are filter backwashing, pool draining, splashing, and leaks. By installing a submeter, variations in water use can be identified, such as unusually high water use caused by leaks, cracks or tears in liners. The meter will help identify abnormal water usage so it can be remedied as soon as it is discovered.
A variety of methods can help reduce pool water use. To prevent water lost from unnecessary backwashing, timers can be installed to standardize the backwash cycle duration and frequency to meet actual needs. Using cartridge filters instead of sand or diatomaceous earth can reduce water use by half because they do not need to be backwashed as often. Backwashing a sand filter will use between 250 and 400 gallons of water, and the same amount to refill your pool, e.g. 800 gallons. A filter installed between the sand filter and the main return line allows clean water to be returned to the pool and not be wasted when backwashing. For more water conservation tips, see ADWR Pools & Spas Conservation Fact Sheet
DECORATIVE FOUNTAINS, PONDS & WATERFALLS
Ponds, fountains and waterfalls should recirculate water by having a reservoir pan to hold water and a pump that circulates it. Water may need to be added several times a week depending on the rate of evaporation, unless the feature has a dedicated line and float. Some communities have regulations on recirculated water in play fountains. New products and kits are becoming available that collect and store rainwater for use in fountains, ponds or waterfalls. The water storage units are usually below ground and a pump recirculates the collected rainwater through the water feature systems. Some communities have ordinances that restrict the type and size of water features to help reduce water loss from evaporation.