Many factors may affect how much water you will save by removing a backyard pool, including all of these:

• Evaporation rate × pool area
• Precipitation × pool area
• Frequency of emptying & refilling × pool volume
• Losses from any pool leaks
• Water used to backflush filters × frequency of backflushing
• Losses from any pump/filter system leaks
• Pool cover usage × evaporation rate
• Increased evaporation due to pool heater use
• Irrigation of replacement land cover

Studies of households that removed backyard pools used two approaches to estimate water savings.

An engineering estimate based on these factors came up with average savings of 26,313 gallons per year.

Another study based on statistical analysis estimated that if the pool had no leaks, annual water savings would average 29,213 gallons per year.

In both cases, pools with a leak used more than twice as much water!