Wastewater Averaging FAQ

Your water meter measures your monthly potable water use, but there is no meter to measure how much wastewater you send into the sewer. An averaging method based on potable water meter readings during the fall/winter months helps us determine how much wastewater you send into the sewer system while excluding seasonal use, like irrigation, that is not treated in a wastewater facility.

Find a copy of your recent bill and locate your bill cycle number at the top left of your bill. Your bill cycle number will determine when your water meter will be read and when your wastewater averaging period will begin. Note: Your actual dates may vary a day or two from the scheduled date. See our wastewater averaging page for more information.

Wastewater averaging takes place during the late fall/winter months to coincide with seasonal low water use. Many households naturally cut back on irrigation, filling pools, washing cars, and other outside water uses during these months so it is easier to estimate the amount of water that goes directly into the sanitary sewer system and must be processed as wastewater.

Since your wastewater average is calculated when your water use is typically lowest, you’ll receive the best possible fixed monthly wastewater fee. The wastewater volume won’t go up - regardless of how much water you use the rest of the year.

Your wastewater average is based on meter readings for the water you use. Meter readings are taken over the course of three consecutive fall/winter months known as the wastewater averaging period. For example, let’s say that during your wastewater averaging period. See the wastewater averaging calculator for more information.

NOTE: To calculate your wastewater average you must have at least 60 consecutive days of water use with a minimum of 100 gallons used per billing period.

Austin Water reads over 250,000 meters in 20 different groups. Each group has a corresponding "billing cycle” that dictates when your water meter will be read and when your wastewater averaging period will begin.

No, the months used to determine your wastewater average are determined by your billing cycle.

Conserving water during the wastewater averaging period will lower the volume of wastewater you will be billed for each month for the next year.

Wastewater is costlier to treat, since it often carries food scraps from the garbage disposal, detergent from washing machines, human waste, toilet paper, and more.  Austin's wastewater is treated to a high quality to keep Austin’s rivers, creeks, and streams free of pollution.

If there is zero usage billed during one of the three months in the current averaging period, the month that billed zero usage is eliminated, and the remaining two months are used in the wastewater averaging calculation. If there is zero usage billed during two of the three months in the averaging period, you will receive a default wastewater average of 5,000 gallons.

If there is zero usage during one of the three months in the current averaging period, the month with zero usage is eliminated, and the remaining two months are used in the wastewater averaging calculation. If there is zero usage during two of the three months in the averaging period, your wastewater service will be based on actual water usage, until a wastewater average can be determined in the next wastewater averaging period. Commercial customers with irrigation meters bill wastewater at the same volume as their domestic water use.​​​​​​​