Plumbing repair · San Marcos, Texas
Plumbing repair in San Marcos, TX
Leak, backed-up drain, no hot water, or a frozen line? The largest share of San Marcos's homes (26%) was built 2010 to 2019[1]. Request a licensed plumber who works here. San Marcos, in Hays County and Caldwell County and Guadalupe County — ZIP 78666, counts 77,830 residents (2025 estimate)[2].
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The San Marcos plumbing picture in brief
- Population (2025 est.)
- 77,830[2]+14.9% since 2020
- County
- Hays / Caldwell / Guadalupe[2]city spans more than one county
- Land area
- 40.4 sq mi[3]
- Decade the most homes date from
- 2010 to 2019[1]26% of housing units
- Homes built before 1980
- 23%[1]the highest share of the 15 Austin-area suburbs we cover
- Homes built 1980–1999
- 25%[1]2020–2024
- Homes built 2010 or later
- 33%[1]the 3rd-lowest share of the 15 Austin-area suburbs we cover
- Winter-storm & freeze days, hays zone
- 19[4]2016–2025
- Flood & flash-flood reports within 10 mi
- 21[4]20 flash floods, 2016–2025; flood-prone homes need working drainage and backflow prevention
- FEMA flood-insurance claims, local ZIPs
- 816[5]30 in the last 10 years; 710 paid
What the local data means for plumbing in San Marcos
San Marcos counts 77,830 residents (2025 estimate), growing at a middle-of-the-pack 14.9% since 2020[2]. The city spans 40.4 square miles at 1,925 residents per square mile (the 9th densest) and spans Hays County and Caldwell County and Guadalupe County, served by ZIP code 78666[3].
With 33% of homes built since 2010 and 23% before 1980[1], San Marcos's plumbing runs from brand-new supply lines and fixtures to aging pipe, original valves and water heaters past their rated life.
One ZIP code covers the whole city: 78666[7].
Nearest of the other suburbs we track: Kyle (8.9 mi N), Buda (14.8 mi N) and Dripping Springs (24.2 mi NW)[3].
23% of San Marcos's 30,349 housing units predate 1980 and 33% went up in 2010 or later[1] — the highest pre-1980 share of the 15 Austin-area suburbs we cover; nearby, Kyle (4%), Buda (4%), and Dripping Springs (4%) predate 1980. Houses that old can still have galvanized supply pipe or cast-iron drains — especially the 9% built before 1960.
The biggest single slice — 26% — was built 2010 to 2019, and the median home dates to 2001[1]. Neighbours from the same era tend to hit the same plumbing problems at the same time.
Freeze risk: the hays forecast zone logged 19 winter-storm, ice or hard-freeze days in 2016–2025, including February 2021; the latest was Jan 20, 2025[4].
Water from the sky is plumbing work too: 21 flood or flash-flood reports within 10 miles over 2016–2025[4], and FEMA logged 816 flood-insurance claims across San Marcos's ZIPs[5]. Homes that take water need working drainage, sump pumps and backflow prevention.
26% of homes heat with utility gas, and 69% of households rent[1]. Tenants: report plumbing failures to the landlord in writing.
Measured against the 15 suburbs on this site, San Marcos records the highest pre-1980 housing share (23%)[1], the oldest housing (by median year built) (2001)[1], the highest renter share (69%)[1], and the 3rd-lowest share of homes built since 2010 (33%)[1].
plumbing help in San Marcos: what to do next
Your request reaches Plumbing repair contractors who serve San Marcos (ZIP code 78666).
Before you call: before the plumber arrives
The San Marcos numbers behind this page
| Measure | San Marcos | Median of 15 | Difference |
|---|---|---|---|
| Built before 1960 | 9.2% | 1.5% | 8 pts higher |
| Built before 1980 | 23% | 4% | 19 pts higher |
| Renter-occupied | 69% | 31% | 39 pts higher |
| Built 2010 or later | 33% | 50% | 17 pts lower |
| Utility-gas heat | 26% | 37% | 11 pts lower |
| Flood reports (10 mi) | 21 | 17 | 4 more |
| Median year built | 2001 | 2010 | 9 years older |
Biggest gaps first. Medians are middle values across the Austin-area suburbs we cover, drawn from the same sources.
| City | Flood reports | NFIP claims | Freeze days |
|---|---|---|---|
| San Marcos | 21 | 816 | 19 |
| Kyle 8.9 mi | 31 | 835 | 19 |
| Buda 14.8 mi | 28 | 67 | 19 |
| Dripping Springs 24.2 mi | 6 | 42 | 19 |
| Bee Cave 30.0 mi | 17 | 2 | 22 |
| Lakeway 33.4 mi | 8 | 353 | 22 |
| ZIP | Claims | Paid | Busiest year |
|---|---|---|---|
| 78666 | 816 | $29,647,337 | 2015 (463) |
ZIPs extend past city limits.
| Date | Type | Distance |
|---|---|---|
| Jun 12, 2025 | Flash Flood | 8.1 mi |
| Jun 12, 2025 | Flash Flood | 3.0 mi |
| Oct 26, 2023 | Flash Flood | 0.1 mi |
| Oct 26, 2023 | Flash Flood | 1.1 mi |
| Oct 26, 2023 | Flash Flood | 6.7 mi |
| Oct 26, 2023 | Flash Flood | 3.0 mi |
| Oct 14, 2021 | Flash Flood | 1.7 mi |
| Sep 29, 2021 | Flash Flood | 3.0 mi |
| Built | Units | Share | Margin of error |
|---|---|---|---|
| 2020 or later | 2,153 | 7.1% | ±467 |
| 2010 to 2019 | 7,830 | 25.8% | ±774 |
| 2000 to 2009 | 5,734 | 18.9% | ±792 |
| 1990 to 1999 | 3,327 | 11.0% | ±623 |
| 1980 to 1989 | 4,319 | 14.2% | ±725 |
| 1970 to 1979 | 2,839 | 9.4% | ±548 |
| 1960 to 1969 | 1,341 | 4.4% | ±344 |
| 1950 to 1959 | 1,357 | 4.5% | ±308 |
| 1940 to 1949 | 742 | 2.4% | ±319 |
| 1939 or earlier | 707 | 2.3% | ±237 |
ACS 2020–2024 estimates; margins of error are the Census Bureau's 90% intervals.
| Measure | Value |
|---|---|
| Housing units | 30,349 |
| Detached single-family | 10,628 (35%) |
| Occupied homes | 28,013 |
| Owner-occupied | 8,630 (31%) |
| Renter-occupied | 19,383 (69%) |
| Median home value | $310,400 |
ACS 2020–2024 estimates.
| Main heating fuel | Homes | Share | Margin of error |
|---|---|---|---|
| Electricity | 19,824 | 70.8% | ±1,136 |
| Utility gas | 7,340 | 26.2% | ±742 |
| Bottled or tank gas (propane, butane, etc.) | 687 | 2.5% | ±301 |
| No fuel used | 127 | 0.5% | ±80 |
| Coal or coke | 16 | 0.1% | ±25 |
| Solar energy | 10 | 0.0% | ±17 |
| Other fuel | 9 | 0.0% | ±15 |
| ZIP (ZCTA) | Share of San Marcos's land | Share of the ZIP inside the city |
|---|---|---|
| 78666 | 91% | 17% |
Dated heat and freeze records for the HAYS forecast zone: see the county list.
San Marcos plumbing questions
Are San Marcos homes likely to have old galvanized pipes?
Only an inspection can say, but age is the clue: 9% were built before 1960 and 23% before 1980[1].
How often do pipes freeze in San Marcos?
The record for San Marcos's forecast zone shows 19 winter-storm or freeze days over 2016–2025, in 8 different years[4].
Which ZIP codes are covered in San Marcos?
78666[7], in Hays County. Nearby suburbs with their own pages: Kyle (8.9 mi), Buda (14.8 mi), and Dripping Springs (24.2 mi)[3].
I rent in San Marcos. Who arranges the repair?
69% of occupied San Marcos homes are rented[1], the highest share of the 15 Austin-area suburbs we cover. Tell your landlord or property manager in writing first; your lease says who arranges repairs.
Sources
- Census ACS 2020–2024 5-year (keyless bulk)
- Census population estimates, Vintage 2025
- Census Gazetteer 2025
- NOAA Storm Events Database
- OpenFEMA NFIP claims
- Texas State Board of Plumbing Examiners (link unverified)
- Census 2020 ZCTA–place file
Data pulled Sep 28, 2026. Full citations and method.