Your yard uses city water. Your roof collects rainwater.
Enter your Austin address and see how much rainwater your roof could capture to irrigate your landscape. Instant, property-specific estimate with no signup.
We don't install anything
RainwaterIQ is an independent Austin rainwater assessment. We use your address to estimate what your roof could capture, from public rainfall data and your building's footprint, and we show you the number before asking for your email. If you decide you want quotes from local installers later, you can make that call on your own timeline.
Store rain for your landscape
Austin watering schedules can change with conservation stages. Check Austin Water for the current rules. Captured rainwater can offset some outdoor city-water use when rain and storage allow.
Rain that lands on your roof between watering days is water you could be storing for your landscape instead of watching it run to the storm drain.
Source: Austin Water (watering schedule and residential rates).
Three steps. About a minute. No account.
You see a real, property-specific estimate before we ask for your email.
Enter your address
The only thing we need to start. No name, no phone, no signup.
We look up your roof and your rainfall
We look for building geometry, use a labeled estimate if it is unavailable, and apply Austin's long-term rainfall normal.
You get your irrigation number
Estimated gallons your roof could capture in a year, plus a 0–100 Rainwater Potential Score that explains what's driving it.
The math, in the open
Your estimate uses a documented formula and assumptions. This is how it is built.
Gallons ≈ your roof footprint × Austin rainfall × 0.623 × collection efficiency
0.623 gallons per inch, per square foot
One inch of rain drops this much water on one square foot of roof. It's the standard industry constant, the same one the Texas Water Development Board uses.
Austin rainfall: about 36.25 inches a year
We use the NOAA 1991–2020 30-year climate normal for the Austin–Camp Mabry station, a long-record central Austin station, rather than a single wet or dry year. The number stays stable and reproducible. We use this station across the Austin metro. Rainfall at your property and in any single year will vary.
Collection efficiency: about 85%
Real systems never capture every drop. First-flush diversion, gutter spillage, and overflow all take a share. The 85% factor is an assumption, not a simulation of your tank. Actual usable water depends on rainfall timing, storage, and demand.
Your roof footprint, not a city average
Where available, footprint comes from City of Austin 2023 building geometry, so the estimate is specific to your property. When measured geometry isn't available for an address, we fall back to an estimate and label it clearly on your result.
Sources: NOAA NCEI U.S. Climate Normals (1991–2020), Austin–Camp Mabry station; Texas Water Development Board rainwater harvesting guidance; City of Austin 2023 building footprints. Rebate and regulation figures are date-stamped and flagged for review when their review dates pass.
A few things worth knowing before you start
Austin-specific facts behind the estimate, each one sourced.
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A 2,000-sq-ft Austin roof could capture about 38,400 gallons a year using the 36.25-inch Camp Mabry rainfall normal, 0.623 gallons per inch per square foot, and 85% collection efficiency. This is a worked example, not an average Austin roof.
Sources: NOAA 1991–2020 climate normals and Texas Water Development Board rainwater harvesting guidance.
- Austin Water: Residential Rainwater Harvesting Rebate Up to $5,000 (capacity-based)
Austin currently offers qualifying rainwater-harvesting rebates of up to $5,000. Eligibility and the final rebate amount depend on system design, storage capacity, and program requirements.
Rebate requires meeting Austin Water program rules; pre-approval and specific system criteria typically apply. Confirm current terms before purchasing.
Source: Austin Water: Water Conservation Rebates · verified 2026-08-30
- Stormwater / Drainage Charge Reduction ~$2.90-$4.90/month (example, tank-size dependent)
Capturing rainwater on-site may qualify your property for a modest monthly drainage (stormwater) charge reduction, often a few dollars per month for a ~1,000-gallon tank.
Drainage-charge reductions depend on impervious-cover and program criteria; amounts vary.
Source: City of Austin: Drainage Charge · verified 2026-08-30
- Texas Rainwater Harvesting Incentives & Protections Sales-tax exemption on equipment
Texas actively encourages rainwater harvesting: rainwater-harvesting equipment is exempt from state sales tax, and state law limits how HOAs can restrict residential systems.
Exemptions and HOA protections have specific statutory conditions; verify current rules.
Source: Texas Water Development Board: Rainwater Harvesting · verified 2026-08-30
Incentives and rules change. These are educational summaries with sources and last-verified dates (latest: 2026-08-30). Confirm current terms before purchasing. We never guarantee eligibility or a specific amount.
Irrigation rainwater questions
How often can I water my Austin lawn right now?
Watering days and restrictions depend on the current conservation stage and irrigation method. Check Austin Water for your current schedule and the rules for using captured rainwater.
Can I use rainwater for drip irrigation and garden beds?
Yes. Landscape and garden irrigation is one of the most common non-potable uses for harvested rainwater, and it avoids treated city water for outdoor use. Your estimate shows how much your roof could capture over a year.
Will this lower my water bill?
Austin bills water on inclining-block rates, so heavy outdoor use is charged at higher tiers. Offsetting some outdoor use with captured rainwater can reduce that, but the actual savings depend on your usage, rates, and system. We do not promise a specific dollar figure.
See what your roof can do
Enter your Austin address for a property-specific estimate. No account required.
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