West Lake Hills vs. City of Austin in 78746: Taxes, Building Rules & Septic (2026)
September 22, 2026
September 22, 2026
Last updated: September 22, 2026 · By Johnny Ronca, SERHANT. Luxury Associate Broker
The 15-Second Answer
A 78746 address can sit in the City of Austin, the City of West Lake Hills, the City of Rollingwood or unincorporated Travis County, and that choice changes your city tax bill, your building rules and who answers a 911 call. For 2026, Austin's city rate is $0.579948 per $100 versus $0.174896 in West Lake Hills. West Lake Hills also has its own tree, impervious cover and septic rules. Check any address on TCAD before you write an offer.
After 20+ years, 300+ closings and $250M+ in Austin sales, the most expensive surprise I see in 78746 isn't a foundation issue. It's a buyer who assumed "Westlake" meant one set of rules. It doesn't. The zip code is a mail route. The city limit line is what sets your city taxes, your permits and your services, and in 78746 those lines zigzag.
Here's how the four jurisdictions compare, how to check any address in five minutes, and what it means if you're planning to renovate, add a pool or tear down in West Lake Hills, Rollingwood or the City of Austin side of 78746.
It depends on the street. 78746 includes parts of the City of Austin, all of West Lake Hills and Rollingwood, and unincorporated Travis County.
The unincorporated pockets are bigger than most people realize. Travis County ESD No. 9, which runs the Westlake Fire Department, says it serves the cities of Rollingwood and West Lake Hills plus unincorporated areas including Lost Creek, Rolling Hills West, Westwood, Camelot, Rob Roy, St. Stephens, Rivercrest and Riverhills.
Lost Creek is the best example of how this can change. Austin annexed it in December 2015. Then, under a 2023 state law (HB 3053) that required large cities to let certain recently annexed areas vote, Lost Creek residents voted on May 4, 2024 to leave, with 91.29% in favor according to KUT. The City's disannexation ordinance (No. 20240829-163) released about 657 acres from the full-purpose city limits, effective September 9, 2024. So older listing sheets and tax estimates for Lost Creek may be out of date.
Street names and marketing names don't settle it either. A home can say "West Lake Hills" on the listing and sit in unincorporated Travis County, or say "Austin" and sit in Rollingwood. Always check.
Look the property up on the Travis Central Appraisal District (TCAD) site and read the list of taxing entities.
The City of Austin also publishes jurisdiction and annexation information and address ranges for annexed and disannexed areas. I run this check on every 78746 address before we talk price.
The City of Austin's rate is more than three times West Lake Hills' rate. Everything else on your bill (school, county and other districts) stacks on top of whichever city you're in.
Jurisdiction | City rate (per $100) | Notes |
|---|---|---|
City of Austin | $0.579948 (FY 2026-27) | Up from $0.524017 in FY 2025-26, per the City. Community Impact reports a 20% city homestead exemption. |
West Lake Hills | $0.174896 (FY 2026-27) | Adopted Sept. 9, 2026, down from $0.176783. Average city tax on a residence: $3,918.36. |
Rollingwood | Check the city's FY 2026-27 budget | Community Impact reported an average city tax of $5,014.22 per home under the FY 2025-26 rate. |
Unincorporated Travis County | No city tax | County, school and special districts (such as ESD No. 9) still apply. |
To make it concrete, on $2,000,000 of taxable value the city portion alone works out to about $11,599 at Austin's rate and about $3,498 at West Lake Hills' rate, before any exemptions. That's a rough illustration, not your bill. Your real number depends on your appraised value, exemptions and every taxing unit on your TCAD record, so use the Travis County tax estimator or ask me to run it.
Rates also move. Austin's rate rose after voters rejected Proposition Q, and Community Impact reports the FY 2026-27 rate is the most the City could adopt without an election. West Lake Hills has been drifting slightly down. Rollingwood's council postponed its final FY 2026-27 rate vote into mid-September, so confirm the adopted figure on the city's site.
West Lake Hills runs its own permitting, with slope-based impervious cover limits and one of the stricter tree ordinances in the area.
The city reviews projects by type, with separate submittal checklists for Type II and Type III development. Here's what I tell clients to expect:
If you're buying a West Lake Hills home to expand or rebuild, I want an architect who works in the city regularly to look at the survey, slopes and tree survey during your option period.
Austin regulates trees 19 inches and up on residential lots, and lakefront lots may also fall under the Lake Austin (LA) zoning district.
The City says trees 19 inches or more in diameter, measured 4.5 feet above ground, are regulated on residential property. Removing one, pruning 25% or more of its canopy, or working in its critical root zone requires a Tree Ordinance Review Application, which the City says usually takes up to 10 business days once it's complete. Applications go through the Austin Build + Connect portal.
For waterfront homes on Lake Austin, the LA district adds a shoreline setback and slope-based impervious cover limits, and City of Austin dock rules apply on Lake Austin even when the house itself is outside city limits. I cover that in my guide to Lake Austin waterfront homes.
Septic is common in West Lake Hills and unincorporated 78746, so confirm it for every property and budget for the rules that come with it.
In West Lake Hills, the city's own on-site sewage facility (OSSF) ordinance sets the rules. According to the city code:
In unincorporated Travis County, septic permits go through Travis County Transportation and Natural Resources. On the City of Austin side, city sewer is more common, but never assume.
What I check on a septic home: the permit and license, the last inspection and pumping records, the system type, and where the drainfield sits. That last one matters a lot. A septic system is designed for a certain wastewater load, and the drainfield location can limit where a pool, guest house or addition can go. If your plans include more bedrooms, talk to a septic designer before you close.
West Lake Hills and Rollingwood have their own city police, unincorporated areas rely on the Travis County Sheriff, and ESD No. 9's Westlake Fire Department covers much of the non-Austin side.
In West Lake Hills, Community Impact reports that 38% of the FY 2026-27 general fund goes to the police department. ESD No. 9 says it protects about 17,000 residents across roughly 17 square miles from three fire stations, covering West Lake Hills, Rollingwood and the unincorporated areas listed earlier. When Lost Creek and other areas voted to leave Austin, KUT noted that services like fire and police would shift to the county. City of Austin addresses are served by Austin's police and fire departments.
No. City limits and school district lines are separate, and much of 78746 is in Eanes ISD regardless of the city.
Eanes ISD's current campuses are Barton Creek, Bridge Point, Cedar Creek, Eanes and Forest Trail elementaries, Hill Country and West Ridge middle schools, and Westlake High School. (Confirm assigned campuses for any specific home with Eanes ISD.) See my Eanes ISD homes guide for how the district breaks down by neighborhood.
Neither is automatically better. West Lake Hills usually wins on city taxes, while the Austin side can be simpler for sewer. The right answer depends on the specific lot.
If you're buying a finished home and plan to hold it, the lower West Lake Hills rate adds up over time. If you plan a major renovation, the lot's slope, trees and septic may matter more than the tax rate. And if you're comparing Austin-side neighborhoods like Davenport Ranch or Westlake Highlands, check each address on TCAD rather than going by the neighborhood name. For a broader look at the area, start with my complete 78746 guide.
No. West Lake Hills is its own incorporated city with its own council, police department, permits and tax rate. It shares the 78746 zip and Eanes ISD with nearby parts of Austin, which is why people mix them up.
The city adopted $0.174896 per $100 of value for FY 2026-27 on Sept. 9, 2026, down from $0.176783. That's only the city portion. Eanes ISD, Travis County and other taxing units are added on top.
The City of Austin's FY 2026-27 rate is $0.579948 per $100, up from $0.524017 the year before. Community Impact reports the City offers a 20% homestead exemption. Other taxing units are billed on top.
Not anymore. Lost Creek voted on May 4, 2024 to leave the city, and Austin's ordinance releasing about 657 acres took effect Sept. 9, 2024. It is now unincorporated Travis County. Confirm any specific address on TCAD.
Search the property on the Travis Central Appraisal District website and look at its taxing jurisdictions. If a city is listed, that's the city. If none is listed, it's unincorporated Travis County.
Usually, yes. The city requires a no-fee permit for most removals. One tree under 10 inches in diameter can come out with a permit once a year, and removing a tree 14 inches or larger requires a variance. Replacement requirements apply.
Many are. The city regulates septic systems itself, with inspections every 7 years outside the Edwards Aquifer Recharge Zone and every 3 years inside it, and new owners must request a license transfer. Confirm the system for any home you're considering.
Travis County ESD No. 9, which operates the Westlake Fire Department. It also covers unincorporated areas including Lost Creek, Rob Roy, Rivercrest and Camelot.
No. School district lines are separate from city limits. Much of 78746 is in Eanes ISD, but confirm on TCAD and use the Eanes ISD SchoolSearch map for campus assignments.
Because jurisdiction, septic and impervious cover can change what a home is worth to you, and those checks need to happen fast. I run them on every 78746 address before we talk price.
Not sure which side of the line a home is on?
Send me any 78746 address and I'll check the jurisdiction, estimate the tax picture and flag septic, tree and impervious cover issues before you make an offer.
Book a 15-minute call with Johnny →
Or text 78746 to (512) 797-0965
Johnny Ronca
SERHANT. Luxury Associate Broker · 20+ years · 300+ closings · $250M+ in sales
Your insider guide to buying smart in Austin's market. 11 chapters covering undervalued neighborhoods, 2/1 buydown strategies, off-market deals, school rankings, and expert tactics from a Top 1% agent with 270+ closed transactions.
Stay up to date on the latest real estate trends.
I am committed to guiding you every step of the way—whether you're buying a home, selling a property, or securing a mortgage. Whatever your needs, I've got you covered.
7415 SOUTHWEST PKWY BLDG 2 STE 200 AUSTIN TX 78620