How is my water bill calculated?

Learn more about the costs that go into your monthly water bill, the tiered billing structure, and the difference between the fixed charges and variable rates: Understanding Your Bill.

What can I do to lower my water bill?

Check for water leaks Check for water leaks
Self-audit your irrigation system Self-audit your irrigation system
How to conserve water
Learn how to conserve water
Check your water meter Check your water meter

What is the city's response to high water bills?

Grand Prairie Water takes your concerns seriously and has investigated possible causes of higher-than-expected bills. We look at water usage patterns and historical trends; and study for possible leaks, billing errors and meter issues.

As promised, the City of Grand Prairie has conducted an independent audit of its water metering and billing operations. View water audit results.

So why are bills so high? 

Higher water bills occur for one or more of three reasons:

  1. customer consumed more water
  2. leak
  3. misread meter

The most common causes of high water use are irrigation systems and/or leaks.

High Water Consumption and Tiered Billing Structure

Grand Prairie, along with cities across the country, uses a tiered water rate structure for all residential water customers. This structure is part of the city’s Water Conservation Plan, mandated by the State, designed to encourage water conservation. Customers who use less water not only buy fewer gallons, but also enjoy lower rates on what they do buy. The more water a customer uses, the more gallons they must buy and if that total exceeds 20,000 gallons in a month, the water rate goes up too. High levels of water usage can get expensive quickly.

The City of Grand Prairie is a water customer of the Dallas Water Utilities and Fort Worth Water, which provide the city with treated water. As the city purchases water in higher volumes for its customers, rates charged to the city rise proportionally for raw water purchases, water treatment, chemicals, debt service to fund federal environmental mandates, and infrastructure—in addition to any additional rate increases levied by Dallas or Fort Worth. As with other cities, these costs are passed through to the retail customer.

Water rate per 1,000 gallons (Residential)

  Monthly Gallons Cost Per 1,000 Gallons  
Lifeline 0 to 3,000 $0.12 Low
Tier 1 0 to 20,000 $4.04 Average
Tier 2 21,000 and Over* $7.24 High
*After 1st 20,000 gallons at the "Lifeline" rate, each additional 1,000 gallons is charged the Tier 2 rate.

View water bill comparison based on gallons used for Lifeline vs. Tier 1 vs. Tier 2 (PDF)

As shown in the table below, the majority of Grand Prairie residents use less than 20,000 gallons, meaning they stay within "Lifeline" (the lowest) and Tier 1 billing rates. Only a small percentage of residential customers use enough water to be billed the Tier 2 rate.

  Monthly Gallons APR MAY JUN JUL AUG SEP
Lifeline 0-3000 27.36% 27.41% 23.63% 18.02% 13.04% 14.01%
Tier 1 4000-8000 54.35% 55.58% 52.68% 41.81% 31.05% 36.80%
Tier 1 9000-13,000 13.51% 12.92% 16.61% 20.31% 20.74% 21.74%
Tier 1 14,000-20,000 3.71% 3.14% 5.27% 12.20% 17.17% 15.73%
Tier 1 Totals   71.57% 71.64% 74.56% 74.31% 68.95% 74.26%
Tier 2 21,000-30,000 0.84% 0.75% 1.43% 5.51% 11.38% 8.03%
Tier 2 31,000 & Over 0.23% 0.20% 0.37% 2.16% 6.63% 3.70%
Tier 2 Totals   1.07% 0.95% 1.81% 7.67% 18.01% 11.73%
    100% 100% 100% 100% 100% 100%
SOURCE: City of Grand Prairie, Information Technology and Management Services Departments


When we look at rainfall in 2015 versus a five-year average, we see wetter than normal January, February, April (double), May (five times the average) and June, which probably means residents enjoyed lush lawns and full swimming pools naturally without having to water.

Then, we see drier than normal July, August and September. So we watered, maybe heavily, to keep our green grass in July and August. That equals a big jump in a bill.

In fact, Grand Prairie water customers used 170 million more gallons of water in July 2015 than July 2014; and 191 million gallons more water in August 2015 than August 2014. And, the bills you receive in September were for four weeks of water use in the July-August timeframe, depending upon your billing cycle. Your October bills are for a four-week period in the August-September timeframe.

2015 DFW Rainfall Chart

Bottom line, if you think your bill is out of whack, call us at 972-237-8200 and let’s take a look at it. Each case is unique. We will evaluate your bill to ascertain what is happening, and ask for your patience as we investigate your individual recent water use trends, perform meter checks and ask for your assistance in checking for leaks, and performing irrigation system audits.

What are the city's water restrictions?

To keep the city’s water supply at a safe level and to comply with the city’s whole sale water purchase contracts, the following restrictions apply at all times:

  • No watering between 10 a.m. and 6 p.m.
  • No watering on Wednesday, Saturday or Sunday.
  • Even numbered addresses may water on Mondays and Thursdays.
  • Odd numbered addresses may water on Tuesday and Fridays.
  • When watering, a constant stream of water should not be allowed to flow into the street drainage.
  • Watering during precipitation is prohibited. Rain sensors are required on newer watering systems.


  • Handheld and soaker hoses are allowed to be used any time.