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Technologies - Pools, Spas and Water Features

Pools, Spas and Water Features, Photo: Microsoft Clip ArtSwimming 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 6 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.

See: ADWR's Pools and Spas Fact Sheet Acrobat Icon PDFs (187 KB)

Pool Backwash Timers, Filters, and Covers

Pools, Spas and Water Features, PhotoA 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.

Pools, Spas and Water Features, Photo

To reduce the frequency of draining pools, pools can be treated with additives that bind and coagulate pool salts so they can be removed from the water. Splash troughs that rim the pool catch excess water and drain it back into the pool. Regular meter readings will help detect unusually high water use caused by leaks or cracks.


Pools, Spas and Water Features, PhotoTo reduce pool evaporation, pool covers can be placed over the pool when the pool is not in use. They not only greatly reduce evaporation, they help keep debris out of the pool and backwash filter. Using a reflective pool cover will help reduce the heat retention of the water.

Liquid pool covers are also gaining in popularity. These usually consist of a biodegradable alcohol containing a chemical that creates a mono-molecular film over the water surface. This very thin film floats on the water, increases the surface tension and prevents evaporation. The chemical must be replenished over time so the expense is ongoing. Dispensing devices on the market slowly add the liquid to the pool to minimize effort. 

Pond & Fountain Recirculation and Rainwater Systems
Pools, Spas and Water Features, Photo

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.