Water used to fill the pool is not free. The charge for the water used is based on consumption just like the water used to take a shower or to do the dishes. It is billed per hundred cubic feet based on current water rates.
However, You can request an adjustment for sewer charges for the water you use to fill your pool. Before beginning to fill your pool, please contact Customer Service at (662) 286-2263 the day before you plan to start. Call again after you finish. Your meter will be read before you begin and after you are finished to determine your sewer adjustment.