How much emergency water could your home capture?
On-site rainwater storage adds resilience during drought restrictions and outages. See how much your Austin roof could capture, from just your address.
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.
When the water stops, on-site storage is what you have.
Drought restrictions and utility outages both put pressure on a home's water. Rainwater you've already captured and stored gives you a reserve that doesn't depend on the city on its worst day.
One honest caveat: stored rainwater is not automatically safe to drink. Potable use requires proper treatment, testing, and design. Plan any drinking-water use with a qualified installer. For irrigation, flushing, and general non-potable resilience, your roof is a real reserve.
Source: Texas Water Development Board rainwater harvesting guidance.
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 emergency water 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.
Emergency water questions
Is stored rainwater safe to drink?
Not automatically. Stored rainwater is not automatically potable. Drinking-water use requires proper treatment, testing, and system design. Plan any potable use with a qualified installer. For irrigation, flushing, and general non-potable resilience, your roof is a real reserve.
How much emergency water could I store?
That depends on your roof size, your rainfall, and the storage you install. Your estimate shows how much your roof could capture over a year; an installer can size a tank to the reserve you're aiming for.
Why keep on-site water in Austin?
Drought restrictions and utility outages both put pressure on a home's water supply. Water you've already captured and stored gives you a reserve that doesn't depend on the city on its worst day.
See what your roof can do
Enter your Austin address for a property-specific estimate. No account required.
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