The best way to avoid wasting water in a swimming pool is to keep it in pristine condition year-around so it won’t need to be drained for years.
After re-plastering our pool, we immediately signed up with a pool service and had sparkling-clean water at all times and did not need to drain it for 11 years. Replacing the water in your pool will be very expensive under the new water rates, so you might as well spend your money on maintenance.
I recently spied on my neighbors using Google Earth. Of the seven nearby pools I located, only two were being maintained at the time the photos were taken. An unmaintained pool is a breeding ground for mosquitoes, which may expose you to several serious diseases.
Also, consider getting a pool cover to reduce evaporation. There are several options, including retractable covers, floating covers and the so-called “liquid pool covers.” Each has advantages and disadvantages.