Blog · For installers
How to add rainwater harvesting to a plumbing, irrigation or landscape business in Texas
Rainwater harvesting is not a new trade. It is gutters, a tank, a pump, filters and a tie-in, and each part already belongs to someone. Here is who does what in Texas, and how a plumbing, irrigation or landscape business adds the whole job.
BlueSignal · October 8, 2026
Who does which part
| Part of the job | Who does it in Texas |
|---|---|
| Gutters, downspouts, first flush, tank and pad | Any contractor; check your city’s permit rules |
| Pump, filters and a tie-in to the building | A plumber licensed by the Texas State Board of Plumbing Examiners |
| Irrigation fed from the tank | A TCEQ licensed Landscape Irrigator |
| Backflow assembly testing | A TCEQ licensed Backflow Prevention Assembly Tester |
| A new circuit for a pump | A licensed electrician |
Texas has no separate rainwater license. ASSE Series 21110 is the industry’s rainwater installer credential, and ARCSA/ASPE/ANSI 63-2020 is the design and installation standard.
Sizing a system
A roof yields about 0.623 gallons per square foot per inch of rain, less what the gutters and first flush lose. The Texas Water Development Board manual uses 75 to 90 percent collection efficiency. The free tank calculator runs that math for an address, and the Rain Planner adds the monthly rainfall and a year of tank levels.
Rebates and tax rules
Many Texas cities, utilities and groundwater districts pay toward a rainwater system, and Texas exempts rainwater harvesting equipment from sales tax. The Rain Planner lists the programs that may apply to an address; the program decides.
Selling and pricing the job
- Size the system from the roof and the use.
- Quote your labor and the equipment as one proposal the homeowner signs online.
- Add a monitor if the water is used indoors or for animals, so the owner sees a change between lab tests.
- Leave the owner a maintenance schedule: gutters, first flush, filters and the tank.
BlueSignal’s free proposal tool builds that proposal under your business, with BlueSignal equipment at the price BlueSignal sells it and your labor at yours.
Training
BlueSignal University has a free Rainwater Installer track and the course that ends in the BlueSignal Certified Installer credential. The credential certifies completed training; it is not a license, insurance or permit. Start at /installers.
Questions
Do I need a license to install a rainwater system in Texas?
Not a rainwater license. The plumbing tie-in needs a licensed plumber, irrigation needs a TCEQ Landscape Irrigator, and a new circuit needs a licensed electrician. Check your city’s permit rules for the tank.
What is ASSE 21110?
The ASSE Series 21110 Rainwater Catchment Systems Installer credential, which takes classroom time and hands-on experience. The ARCSA Foundation tells homeowners to ask for it.
How do I size a rain tank?
Roof area times rainfall times 0.623, less collection losses, against the monthly use. The free tank calculator does it.