Denver, CO
Backflow testing in Denver
Updated · Editorial team; not yet technically reviewed
Short answer
Denver Water requires backflow prevention assemblies to be tested when installed and every year after that by a certified tester. Irrigation assemblies are tested when the water is turned on for the season, with the irrigation testing season running from May to September, and results go to Denver Water's Cross-Connection Control office.
What's different in Denver
Denver Water customers must have backflow prevention assemblies tested upon installation and annually thereafter by a certified backflow prevention assembly tester. [1]
Denver Water's irrigation backflow testing season runs from May to September, and irrigation assemblies are tested as the water is turned on for the season. [1]
Denver Water sends a testing reminder notice 30 days before the annual test is due. [1]
Irrigation systems must be protected with either a reduced pressure principle assembly (RP) or a pressure vacuum breaker (PVB), depending on installation requirements; residential requirements are assessed based on site hazards. [1]
Pair the test with spring startup
Because irrigation assemblies are tested as the water is turned on, many Denver homeowners book the backflow test with their sprinkler startup. A freeze can crack a PVB or RP left charged over winter, so a spring test also catches winter damage before the system runs all summer.
RP or PVB: which you have
| Device | Where it's used | Notes |
|---|---|---|
| Pressure vacuum breaker (PVB) | Many residential sprinkler systems | Must sit above the highest sprinkler head; vulnerable to freezing |
| Reduced pressure principle assembly (RP) | Higher-hazard or specific installations | Discharges water when it trips; needs drainage |
Winterizing your assembly
Denver's freezes make winterizing essential: shut off the irrigation supply, drain the assembly and blow out the lines before the first hard freeze. A cracked body or bonnet is a common reason for a failed spring test. For what a backflow preventer does, the device types and how a test works anywhere, see backflow testing.
Further reading: How backflow happens and which devices homes use.
Common questions
How often does Denver Water require backflow testing?
At installation and every year after that, by a certified tester.
When is backflow testing season in Denver?
For irrigation assemblies, May through September, when systems are turned on.
Will Denver Water remind me about my backflow test?
Yes, a reminder notice is sent 30 days before the annual test is due.
Where do Denver backflow test results go?
To Denver Water's Cross-Connection Control office, which accepts reports at [email protected].
Does my Denver sprinkler system need an RP or a PVB?
Denver Water accepts either, depending on the installation requirements and site hazards.
Why did my Denver backflow preventer crack?
Water left inside over winter froze and expanded. Drain the assembly and blow out lines each fall.
Can I test my backflow device myself in Denver?
No. Testing must be done by a certified backflow prevention assembly tester.
Does every Denver house need a backflow assembly?
Irrigation, fire and certain other services do; residential requirements are assessed based on site hazards.
Should I schedule the backflow test with my sprinkler startup?
It's convenient: irrigation assemblies are tested as the water is turned on for the season.
Who repairs a failed backflow preventer in Denver?
A certified tester or licensed plumber; a passing retest is needed afterward.
More plumbing help in Denver
- Water Line Repair in DenverHow Denver Water replaces customer-owned lead service lines with copper at no direct cost, which homes are most likely affected, and what to do while you wait.
- Leak Detection in DenverDenver Water customers own the service line and meter pit, Denver Water isn't liable for damage from them, and how leak detection finds a break before you dig.
- Toilet Installation in DenverDenver Water's toilet rebate: up to $100 for a WaterSense toilet averaging 0.8 gallon per flush or less, two per home per 10 years, apply within 90 days.
- Backflow Testing: the full guideWhat backflow is, which homes and businesses need backflow preventers, how annual backflow testing works, and what happens if a device fails.
- Plumbing in DenverLocal water, housing and climate conditions, and the calls Denver homes need most.
How other cities handle it
- Backflow testing in AustinAustin Water's backflow testing rules: who may test, the 5-day report deadline, online filing, and the irrigation rebates that pair with an upgrade.
- Backflow testing in San AntonioSAWS backflow testing rules for San Antonio: the June 30 annual deadline, the codes behind it, reminder notices, and what a 10-day notice means.
- Backflow testing in SeattleSeattle Public Utilities backflow testing rules: annual tests by your anniversary date, Washington-certified testers, reporting, and non-compliance charges.
- Backflow testing in PortlandPortland Water Bureau backflow rules: yearly testing by a state-certified tester, the spring timing it prefers, reminder letters with labels, and shutoff risk.
- Backflow testing in CharlotteCharlotte Water backflow rules: residential irrigation tested every 3 years, residential domestic yearly, approved testers, and RP assemblies on irrigation.
- Backflow testing in RaleighRaleigh Public Utilities backflow rules: residential irrigation tested by July 1 every three years, commercial yearly, owner-paid certified testing, and contacts.
- Backflow testing in TampaCity of Tampa Water Department backflow rules: residential tests every two years, commercial yearly, certified technicians, and the 7-day online reporting rule.
- Backflow testing in Salt Lake CitySalt Lake City Public Utilities backflow rules: tests within 10 days of installation and yearly after, which homes need protection, and secondary water.
- Backflow testing in Colorado SpringsColorado Springs Utilities backflow rules: who must test annually, the July 1 deadline, the $405 fine, licensed testers entering results, and single-family guidance.
- Backflow testing in Fort WorthFort Worth backflow rules: annual tests for commercial and health-hazard assemblies, a three-year cycle for low-hazard irrigation, and registered testers.
- Backflow testing for JEA customers in JacksonvilleJEA residential backflow rules: testing at least every two years by JEA Qualified Vendors, dual checks replaced every five years, and reclaimed-water irrigation.
- Backflow testing in Fort LauderdaleFort Lauderdale backflow rules: residential irrigation tested every two years, commercial yearly, only PVB or RP devices on irrigation meters, and certified testers.
- Backflow testing in DallasDallas backflow rules: lawn irrigation assemblies don't need annual tests, only when new, repaired or replaced; high-hazard assemblies need annual registered tests.
- Backflow testing in HoustonHouston backflow testing: testing companies must register with the city, testers need TCEQ licenses, and gauges need annual calibration reports filed with Houston.
- Backflow testing in PhoenixPhoenix backflow rules: assemblies tested at least yearly, 60 days to test after the reminder letter, then a 72-hour disconnection notice. Who needs one at home.
- Backflow testing in PhiladelphiaPWD backflow rules: test at installation, after any repair and yearly by a City-certified technician, file Form 79-770 within 48 hours.
Sources (1)
- Denver Water, Backflow Prevention Program · checked 2026-10-03