Why does the City of Austin use a wastewater average as the basis for my wastewater bill?

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. 

How do I know the specific dates my water usage will be monitored for my new wastewater average?

Find a copy of your recent bill and and locate your bill cycle number. Your bill cycle number will determine when your water meter will be read and when your wastewater averaging period will begin. See wastewater averaging page for more information.

Why is wastewater averaging done mid-November to mid-March?

Wastewater averaging takes place during the late fall/winter months and coincides with seasonal low water use, when many households naturally cut back on irrigation, filling pools, washing cars, and other outside water uses. Therefore, it is easier to estimate the actual amount of water that goes directly into the sanitary sewer system versus being used for outdoor watering.

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

How is my wastewater average calculated?

Your wastewater average is based on meter readings for the clean water you use. Meter readings are taken over the course of three consecutive fall/winter months known as the wastewater averaging period. For example, during your wastewater averaging period you use:

  • 4,000 gallons of water in month 1
  • 4,000 gallons in month 2 and
  • 5,000 gallons in month 3

After adjusting for the number of days in a month, your wastewater average is 4,333 gallons per month.

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.

Why can't everyone use the same months to calculate their wastewater average?

Austin Water meter readers visit over 900,000 meters in 20 different districts. Each district has a corresponding "billing cycle” that dictates when your water meter will be read and when your wastewater averaging period will begin.  

Can I choose different months to determine my wastewater average?

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

How can I lower my wastewater bill?

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

Why do I pay more for wastewater than I do for my water?

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 in order to keep Austin’s rivers, creeks, and streams free of pollution.

I am a residential water/wastewater customer. How is my wastewater average calculated if I have one or more months of zero consumption during my designated wastewater averaging dates?

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.

I am a commercial water/wastewater customer.  How is my wastewater average calculated if I have one or more months of zero consumption during my designated wastewater averaging dates?

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.