Austin water runs 70 to 126 mg/L hard after softening, mountain cedar pollen coats glass from December to February, and oak pollen follows in spring.
Austin softens its water, which reaches the tap moderately hard and at times just into the hard band, so spots show on dark, sunlit glass without damaging it. Cedar pollen coats windows from December to February and oak pollen follows in spring, so wash in April, high summer or November. Terrain and height split the market, with West Lake Hills priced on access; a single-story exterior runs $330 to $560.
At an average of 93 ppm the supply will mark dark glass in direct sun and will not damage it. The useful detail is the spread: the published range runs from 70 to 126, so the same address sits in soft-ish territory in a wet year and at the top of moderately hard in a dry one, and a rinse policy set during a full-lake spring will underperform during a drawdown.
| Hardness | 70–126 mg/L as CaCO₃ Moderately hard — 4.1 to 7.4 grains per gallon, averaging 5.4, as published by Austin Water. |
|---|---|
| pH | 9.65–9.74 |
| Alkalinity | 51–60 mg/L as CaCO₃ |
| Iron | 0.011–0.027 mg/L |
| Sodium | 18.6–28.5 mg/L |
| Chloride | 34–52 mg/L |
| Total dissolved solids | 154–156 mg/L |
| Disinfectant | chloramine |
| Source and treatment | Surface water from the Lower Colorado River as it flows through Lake Travis and Lake Austin, part of the Highland Lakes chain, treated at the Handcox, Davis and Ullrich plants · Coagulation, flocculation, sedimentation and filtration with a polymer feed for high-turbidity events, powdered activated carbon for taste and odour, copper sulfate on the raw-water piping against zebra mussels, lime softening, then a chloramine residual and fluoride. Operators check disinfectant residual, turbidity, pH, alkalinity and softening levels at least every two hours. · The plant softens. |
Not in the report: corrosion index and manganese.
SOURCE · Austin Water 2nd Quarter 2026 Water Quality Summary, finished-tap columns for the Davis, Ullrich and Handcox plants, read with the 2025 Consumer Confidence Report, PWS ID 2270001 (austintexas.gov) · How we source these numbers
Two pollen seasons at opposite ends of the year set the Austin calendar — cedar from December to February, oak in spring — with the usable window between and after them. Mineral spotting rises through late summer as lake levels drop, so the same interval delivers a visibly worse result in August than in April on identical work.
TEXAS SEASON BY SEASON →Austin Water publishes total hardness as 70 to 126 ppm, averaging 93 — 4.1 to 7.4 grains, moderately hard and far softer than San Antonio on the same limestone. The utility also posts monthly and quarterly summaries rather than only an annual report, so the current figure is checkable before a large job. Cedar pollen in midwinter and the tech-corridor commercial cycle define the operating cadence.
Austin Water's own report gives total hardness as a low of 70 ppm, a high of 126 and an average of 93, printed in both units — 4.1 to 7.4 grains per gallon. That is moderately hard, and it is dramatically softer than San Antonio ninety minutes south despite both sitting on Central Texas limestone, because Austin drinks surface water off the Highland Lakes rather than karst groundwater.
The utility publishes monthly and quarterly water quality summaries including total hardness, pH and dissolved solids, not just the annual report. That makes Austin the third city on this site with better-than-annual disclosure, after Minneapolis and Billings, and it means a crew can check the current number before committing to a rinse policy on a large job.
Three plants — Handcox, Davis and Ullrich — treat Lower Colorado River water as it flows through Lake Travis and Lake Austin. A surface supply in a drought-prone basin is the reason the published spread runs nearly two to one: low lake levels concentrate what is dissolved, so the hard end of that range belongs to dry years and late summer.
Hardness figures quoted online for Austin disagree wildly, anywhere from 4.9 to 17 grains, or 114 mg/L. The utility's own 93 average settles it.
Cedar pollen — mountain juniper — runs December through February and is a winter event rather than a spring one. Every surface coats yellow-green, respiratory protection is standard for the crew, and a service calendar imported from a March-pollen market will be scheduled exactly wrong.
Oak pollen follows in spring, so Austin effectively carries two distinct pollen seasons at opposite ends of the year with a workable window between them. That shapes the annual route more than anything in the water does.
Downtown's high-rise and luxury condo concentration is the institutional core of the market, and the tech corridor around it buys on quarterly campus refresh cycles. Both procure formally, which rewards documentation over responsiveness.
West Lake Hills and the western edge are steep, wooded and built for the view — large fixed picture windows on hillside lots with difficult approaches. High value per job, poor route density, and setup time that a flat-market quote will not carry.
Terrain and height split this market. West Lake Hills prices on approach and carry rather than pane count, downtown prices on rigging and out-of-hours access, and the tech corridor prices at bid on quarterly cycles. Across all three, the two pollen seasons compress demand into predictable windows that the annual rate card should reflect.
Moderately hard water and accessible suburban glazing keep a homeowner result realistic for most of the year, and the honest caveat is seasonal rather than technical: in a dry late summer, tap rinsing that worked in spring will spot. The exclusions are the hillside stock west of the city, where the access risk is real, and downtown, which is platform and rope work under building coordination.
OPEN COST ESTIMATOR →2025 annual mean at the Austin Webberville Rd monitor, 2600B Webberville Rd, 5.6 km south-east of the city (EPA site 48-453-0021).
Largest air release: NXP USA Inc. - ED Bluestein Facility, 3501 ED Bluestein Blvd (computers and electronic products), inside the city limits, 36,820 lb in 2024.
Under Austin's Conservation Stage rules, washing cars and power washing outdoor surfaces are allowed only with a hose fitted with a positive shut-off or with a bucket, while hand-held watering is allowed at any time. Austin Water investigates water waste reported through 3-1-1 and on scheduled patrols.
Austin Water, return to Conservation Stage watering restrictions · checked September 2026
Austin bars power-washing wastewater that holds pollutants or cleaning compounds from the storm sewer unless it has been treated. It has to be collected and taken to a permitted sewer-connected facility, a landfill or a waste treatment plant, and it may not go down a toilet, cleanout or manhole at the job site unless that site has an Austin Water permit and a sand and oil interceptor.
Austin Water, wastewater disposal for power washers and mobile car washes · checked September 2026
In Austin, exterior alterations to a historic landmark or to a contributing property in a local or National Register historic district go through the city's historic review, judged against its design standards, so new windows on those buildings need sign-off first. Staff can approve small projects within five business days; larger ones go to the monthly Historic Landmark Commission.
City of Austin Planning, Historic Review · checked September 2026
The central Texas mountain juniper releases huge volumes of cedar pollen from December through February — locally called cedar fever season. Pollen settles on glass in visible yellow clouds on heavy-release days. Sticks tenaciously and needs a surfactant pass.
Live oak and post oak release pollen from late February through early April. Yellow-green pollen layers everywhere in Austin, San Antonio, and the eastern hill country. Heavy enough to require a pre-rinse on most spring jobs.
At an average of 93 ppm the supply will mark dark glass in direct sun and will not damage it. The useful detail is the spread: the published range runs from 70 to 126, so the same address sits in soft-ish territory in a wet year and at the top of moderately hard in a dry one, and a rinse policy set during a full-lake spring will underperform during a drawdown.
Residential window cleaning in Austin typically runs $11–17 per pane or $330–560 for a standard single-story exterior. Terrain and height split this market. West Lake Hills prices on approach and carry rather than pane count, downtown prices on rigging and out-of-hours access, and the tech corridor prices at bid on quarterly cycles.
Austin's drier, frost-free months are February, April, July and August and November, by NOAA's 1991–2020 normals for the Austin-Camp Mabry station, where May brings the most rain. The calendar on this page marks April (after the February 22 bloom) and November (after smoke season and before frost). Frost nights usually run from December 3 to February 20.
Yes, if the rinse is squeegeed off before it dries: Austin Water publishes dissolved solids of 154–156 mg/L, between this site's two dissolved-solids flags. Water left to dry leaves mineral scale; fresh spots lift with a mild acid. It draws on surface water from the Lower Colorado River as it flows.
In Austin the dominant residue patterns include cedar and mountain-juniper pollen (december–february) and spring oak pollen wave. Two pollen seasons at opposite ends of the year set the Austin calendar — cedar from December to February, oak in spring — with the usable window between and after them.
Moderately hard water and accessible suburban glazing keep a homeowner result realistic for most of the year, and the honest caveat is seasonal rather than technical: in a dry late summer, tap rinsing that worked in spring will spot.
High-rise commercial and luxury condo concentration with institutional contract work. Platform and rope access, building coordination, out-of-hours scheduling. West Lake Hills and Hyde Park have their own housing stock and glazing as well.
Just over the Texas line