Lower Bills All Year Long!


Dallas Water Utilities Encourages You to Lower Your Water Bill All Year Long by Saving Water December Through March

Your water charges reflect the costs of cleaning and delivering safe, high quality drinking water to your home. Your sewer charges reflect the costs of collecting wastewater, transporting it to a wastewater treatment plant, cleaning the water to almost drinking water quality, then returning it to the Trinity River. The cleanliness standards for both drinking water and treated sewage are set by the state and federal governments.


Your Water Use Is Metered

To ensure that customers are charged fairly, DWU uses meters to measure water use.


Sewer Use Is Estimated

Because it is not cost effective to meter sewer use, DWU estimates it. To estimate sewer use, DWU uses your winter months average (the average of your water billed in December, January, February and March). This is thought to be the best time to average because customers water their lawns less in the winter. However, if a customer’s current month’s actual water use is less than the winter months’ average, the customer’s sewer bill is based on the actual water use.


How Your Residential Winter Months Sewer Average Is Calculated

Per ordinance (Chapter 49-18.2) the monthly residential sewer charges are based on the average water consumption billed in the months of December, January, February and March, or the actual month’s water consumption, whichever is less, up to a maximum charge of 40,000 gallons per month. This is also referred to as Winter Month Average (WMA). See the following example.


Months Usage
December 120
January 100
February 98
March 110

120 + 100 + 98 + 110 = 428 ⇐ Total winter consumption

428 ÷ 4 = 107 ⇐ Winter Month Average (WMA)

There must be at least two billing cycles (with a minimum of 20 days in each period) in order to calculate an average. If a billing reversal is performed to any of the four averaging months, a new winter month’s average will be automatically calculated. Those not having a minimum of two months will be billed the lesser of the residential class average or the actual usage each month.

To calculate the sewer usage charge for a residential account, multiply the Winter Monthly Average (WMA) or water usages, whichever is less by the current rate divided by 1,000 gallons. Using the above example and the rate for FY 09-10, the sewer usage charge would be:

10,700 x $4.26 = 45,582 ÷ 1,000 = $45.58

For more simple ways to save water, go to our Saving Water Indoors page.