The amount of water used to fill and maintain a swimming pool throughout the year is affected by a variety of factors including:

• Size of the pool (surface area and depth)
• Amount of evaporation (related to local climate)
• Frequency of backwashing
• Leakage
• Frequency and method of pool and pool deck cleaning
• Splashing
• Presence and use of a pool cover
• Temperature of pool water (warmer water evaporates more easily)
• Presence of a fountain or waterfall
• pH and chemical content of pool water
• Individual maintenance habits

Because of the variability of conditions listed above it is difficult to determine how much water a swimming pool will use. By comparing homes with and without swimming pools and correcting for differences in landscape size its estimated that homes with a swimming pool use about 58 percent more water outdoors than homes without a swimming pool (Maddaus and Mayer, 2001). This research indicates that the addition of a swimming pool results in a substantial increase in water use.