Living in Sonterra, TX: what to set up and who to call
Sonterra has no town government of its own, so Williamson County runs its elections and most services, and its children attend Jarrell Independent School District. Oncor delivers the power in Sonterra, but in Texas’s open market you choose the company that sells it.
I’m new in town
What to set up in Sonterra, and who provides it. Tap an answer for the details and where they come from.
Power, water and internet
Who to call to start service at a new address in Sonterra.
Power comes from Oncor
Oncor (Oncor Electric Delivery Co.), an investor-owned utility, serves all of Sonterra.
Start or move service: oncor.com · (888) 875-6279
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from Sonterra MUD
Sonterra MUD supplies Sonterra: about 86% of residents live in its service area. About 13% of homes are outside any mapped community water system, most likely on private wells, which EPA doesn’t regulate. It buys treated surface water (EPA lists Jarrell Schwertner WSC and Lone Star Rwa as sellers) and serves 16,614 people in all.
No health-based violations reported to EPA in the five years to October 2026, like 83% of the 3,525 systems serving 10,001–50,000 people.
The latest lead result on file, the 90th percentile of homes sampled in Jan 2022–Dec 2024, was 0.4 ppb, below the 15 ppb action level that applied. The highest in five years was 3.2 ppb. That’s lower than 65% of similar systems’ latest results.
The system’s full record: EPA ECHO report
EPA SDWIS via Envirofacts (violations pulled Oct 9, 2026) and ECHO (lead samples, 2026Q3); service area: EPA Community Water System Service Area Boundaries v3.0. Violations are counted by the start of their compliance period. TX2460157.
10 home internet providers serve Sonterra
100% of 3,763 addresses can get 100/20 Mbps; 87% can get fiber.
| Provider | Technology | Addresses | Fastest (Mbps) |
|---|---|---|---|
| Optimum | Cable, Fiber | 94% | 940/35 |
| FiberFirst | Fiber | 81% | 5,000/5,000 |
| BEC Communications | Fiber, Fixed wireless | 12% | 2,000/1,000 |
| Spectrum | Fiber | 6% | 1,000/1,000 |
| Heritage Broadband | Fixed wireless | 100% | 1,000/100 |
| SOS Communications | Fixed wireless | 89% | 100/20 |
FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.
We don’t have Sonterra’s trash rules yet
Pickup rules, the dump and recycling in Sonterra.
Where your child goes to school
Public school districts and the school path by grade.
Sonterra is in Jarrell Independent School District.
C−School gradeSee Schools →U.S. Department of Education, NCES Common Core of Data, 2024–25. Enrollment rules and registration are the district’s.
No town hall: the county runs things
Sonterra is unincorporated, so Williamson County is the local government.
Election office: FVAP local election office directory, updated Nov 2025; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Nov 18, 2024.
Sonterra is in ZIP code 76537
ZIP codes where Sonterra residents live, with the share of the town in each.
| ZIP | Post office name | Share of Sonterra | ZIP’s residents in Sonterra |
|---|---|---|---|
| 76537 | Jarrell, TX | 100% | 70% |
Census 2020 ZIP Code Tabulation Areas, by census block; post office names: GeoNames (CC BY 4.0). ZIPs created since 2020 are missing.
Getting around, the ER and the library
One line each; the subject pages have the rest.
ER: CMS hospital data. Library: IMLS Public Libraries Survey, FY2024.
Questions about living in Sonterra
Who supplies Sonterra’s drinking water, and has it had violations?
Sonterra MUD (EPA ID TX2460157). It reported no health-based violations to EPA in the five years to October 2026; 83% of systems its size had none. Its latest lead 90th percentile was 0.4 ppb (Jan 2022–Dec 2024), against a 15 ppb action level.
Who provides electricity in Sonterra?
Oncor (Oncor Electric Delivery Co.), an investor-owned utility.
What internet providers serve Sonterra?
Optimum, FiberFirst, BEC Communications, Spectrum, Heritage Broadband, SOS Communications (FCC, as of December 2025).
What ZIP codes are in Sonterra?
76537. Census 2020 ZIP Code Tabulation Areas.
What school district is Sonterra in?
Jarrell Independent School District.
How do I register to vote in Sonterra?
Texas has no online registration; you can register in person until 30 days before Election Day or by mail (postmarked 30 days before). Elections here are run by the Williamson County Early Voting Clerk. Check your registration at teamrv-mvp.sos.texas.gov.
Sources & dates
Every answer above names its source. Here they are with their dates.
- Water: EPA SDWIS (Envirofacts, pulled Oct 9, 2026), ECHO SDWA 2026Q3, EPA CWS Service Area Boundaries v3.0.
- Power: HIFLD Electric Retail Service Territories (map Aug 2023); EIA-861 final 2025.
- Trash: OpenStreetMap, Geofabrik extract of Oct 9, 2026. © OpenStreetMap contributors (ODbL).
- ZIP codes: Census 2020 ZCTA relationship files; GeoNames postal codes (CC BY 4.0).
- Schools: NCES Common Core of Data, 2024–25.
- Registration: vote.gov, updated Nov 18, 2024 (read Oct 10, 2026). Official sites and area codes: Wikidata.
- Election office: FVAP local election office directory (fetched Oct 10, 2026; each record dated), EAC EAVS 2024 jurisdictions; registration and lookup links from vote.gov’s state data, checked Oct 10, 2026.
- Internet: FCC National Broadband Map, as of December 2025.