Two homes list at the same price, in the same Teravista section of Williamson County, both built the same year, both sold as part of the same 1,500-acre master-planned community. One sits a few blocks north. The other sits a few blocks south. Their tax bills are not the same, and the gap has nothing to do with square footage, lot size, or finish level. It comes down to which side of an internal line each house happens to fall on, a line the sales brochure never draws because it has nothing to do with marketing and everything to do with which government actually built the water and sewer pipes under the street.
Teravista spans both Round Rock and Georgetown, with nearly 3,400 residences governed within Williamson County. That single fact, repeated in almost every listing description, is also the reason the community doesn't have one tax bill. It has several, depending on exactly where a given address sits.
Why a golf-course community needs three water districts
Teravista's water, wastewater, and drainage infrastructure was built and financed through three separate Municipal Utility Districts, organized starting in 1998, ahead of the community's 2001 opening. Two of those districts sit inside Round Rock's extraterritorial jurisdiction. One sits inside Georgetown's.
Extraterritorial jurisdiction, or ETJ, is the term worth knowing before anything else here. It means land close enough to a city to fall under some of that city's planning authority without being annexed into it. Land in a city's ETJ doesn't get city water, sewer, or the tax rate that funds them. Someone else has to build that infrastructure and someone else has to bill for it. That someone else is the MUD.
Each MUD issues bonds to pay for the pipes and repays those bonds through its own ad valorem property tax, collected on the same county tax bill as everything else, but as its own separate line. Two houses can share a mailing address, a school bus stop, and an HOA newsletter, and still answer to three different water districts depending on which side of an invisible boundary they sit on.
What the HOA pays for that the MUD doesn't
Teravista's MUDs were kept narrow by design. They cover water, wastewater, and drainage. They do not fund the pools, the golf course, or the trail system. That job belongs to the Teravista Community Association, the HOA that collects dues separately from anything that shows up on a county tax bill.
That separation is not an accident of paperwork. A utility-only MUD is a cleaner asset for a city to eventually absorb than one that also owns and operates recreation amenities. If Round Rock or Georgetown ever moves to formally annex sections of Teravista, a district that only ever built pipes hands over more simply than one entangled in golf course maintenance and pool schedules. The HOA, not the MUD, is the permanent owner of the lifestyle amenities regardless of what the taxing map eventually looks like.
What the actual gap looks like on paper
None of this is theoretical. Run the same $450,000 home through two different Williamson County taxing-unit combinations, one reflecting a typical arrangement on the Round Rock side, one reflecting the unit combination that Williamson County Appraisal District records show for the Georgetown side of Teravista, and the two bills land roughly $900 apart per year, even before either owner claims a homestead exemption.
| Taxing layer | What it funds | Where it shows up |
|---|---|---|
| City (Round Rock only) | General city services | Only if the address is inside Round Rock's city limits, not its ETJ |
| Independent School District | Round Rock ISD's 2025 rate runs $0.8931 per $100, split between $0.7101 for maintenance and operations and $0.1830 for debt service | Typically the largest single line on the bill |
| Williamson County | County-wide services | Every address in the county |
| MUD | Repays the bonds that built water, sewer, and drainage for that specific district | Only addresses inside that district's boundary |
| Emergency Services District | Fire and EMS, mostly outside city limits | Common on ETJ addresses, ranged roughly $0.074 to $0.100 per $100 across Williamson County's ESDs in 2025 |
The Georgetown-side combination in this comparison also carries a small water control district rate that doesn't apply on the Round Rock side, which is part of what drives the roughly $900 spread. Two houses, same asking price, same builder era, meaningfully different carrying cost.
A homestead exemption doesn't automatically close that gap either. The exemption reduces the ad valorem taxes it applies to, which includes MUD tax, but only if that specific district's board has chosen to offer its own exemption. That's a board-level decision, not a statewide guarantee, and it has to be confirmed with the district directly rather than assumed from how exemptions work elsewhere on the bill.
New construction gets hit before the cap kicks in
Buyers comparing a resale in an established Teravista section against new construction in a still-building phase are comparing two different appraisal trajectories, not just two different price points.
Texas caps how fast a homesteaded property's taxable value can climb in a given year at 10 percent, but that cap doesn't apply in the first year of ownership. Williamson County's 2025 reappraisal cycle showed average value increases of 6.3 percent countywide. Homes built since 2021, the vintage most likely to still sit inside an active MUD repayment period, averaged 19.6 percent. A buyer closing on new construction inside a young district takes the full force of that first appraisal with no cap to soften it, layered on top of a MUD rate that tends to run highest early in a district's life, before enough bonds have been retired to bring it down.
That combination, uncapped first-year appraisal plus a young district's peak rate, is the single biggest reason a new-construction Teravista purchase and a decade-old resale two streets over can carry noticeably different trajectories even when the sale price is nearly identical on day one.
This isn't a one-time quirk of how Teravista was built
The same jurisdictional logic that produced Teravista's three MUDs in the late 1990s is still exactly how Williamson County structures new growth today. In March 2026, Georgetown's City Council took up proposals to annex two developments, Rock Bluff Ranch and Yearwood, both then sitting in the city's ETJ. Rock Bluff Ranch alone plans 2,375 homes across 855 acres east of County Road 245, with developer Freehold Capital Management seeking annexation alongside new in-city MUDs to fund the same categories of infrastructure Teravista's districts were built to cover a generation earlier.
The mechanism doesn't retire once a community is built out. It's the standing method for how Williamson County's growth corridor gets financed, section by section, and it means a district's status, ETJ or annexed, city rate or none, can still shift over the life of a project. Anyone comparing Teravista against a newer community in the same corridor is comparing addresses that may be at very different points in that same annexation-and-bond cycle.
Before you write an offer
The taxing-unit list for any specific Teravista address is a matter of public record, and it's worth pulling before comparing two houses that both happen to say Teravista on the listing.
- Look up the parcel on the Williamson County Appraisal District site and list every taxing unit attached to it, not just the total rate
- Pull the current county tax bill from the Williamson County Tax Office to see how the MUD line and any water control district line are broken out
- Ask the specific MUD's board directly whether it offers its own homestead exemption, since that's a district-level decision rather than something to assume
- Mark May 15 on the calendar if you close on a Williamson County property, since that's the annual deadline for an appraisal protest, and a successful one lowers the base for future years, not just the current bill
Unlike some newer developments elsewhere in the county that stack a Public Improvement District assessment on top of a MUD, Williamson County's own guidance on how those assessments work shows Teravista's structure staying simpler, MUD only, no separate PID layer to track. That's one less moving piece when comparing it against a newer community carrying both.
A few questions worth asking directly
Does the new homestead exemption automatically lower my MUD tax? No. The statewide exemption applies to the school district portion of the bill. Whether a specific MUD offers its own exemption is a separate decision made by that district's board.
Is being inside a MUD a reason to avoid a neighborhood? Not on its own. Financing infrastructure through district bonds is part of how a developer avoids the upfront impact fees a city would otherwise charge, which is part of why new construction in these communities can price competitively against similarly sized homes built inside full city limits.
What happens to my MUD if the city eventually annexes my section? It depends on what the district covers. A utility-only district, which is what all three of Teravista's MUDs were built as, transfers more cleanly than one that also owns recreation assets, since the city only has to absorb pipes and a bond schedule rather than an entire amenity package.
Comparing Teravista against another Williamson County community, or comparing two sections within Teravista itself, is really a comparison of taxing-unit combinations and where each one sits in its own bond repayment timeline. That's a parcel-by-parcel question, not a neighborhood-wide one, and it's worth answering before an offer goes in rather than after closing.
If you're weighing a specific Teravista address against another option in the Round Rock or Georgetown corridor, Team West Real Estate can pull the taxing-unit breakdown for that parcel and walk through what it actually means for a monthly payment before you write anything up.
