County water report

Bexar County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Bexar County, Texas.

Water grade

Water score

67.5

State rank

#18

of 254

Health violations

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

122

65,822 recent measurements

Live streamflow

33%

San Antonio Rv nr Elmendorf, TX

Water at a glance

Key Water Indicators for Bexar County

EPA SDWIS

Safety Grade

Score: 67.5 / 100

EPA SDWIS

Active Violations

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

33% of mean

San Antonio Rv nr Elmendorf, TX

EPA WQP

Monitoring Sites

122

65,822 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

67.5/100

Health violations

Health-based violations

Violations per 100K served

2.2

Population-normalized SDWIS rate

Data center water stress

Bexar County has 42 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #32 nationally by combining its water score with mapped data center density.

DCWSI

79.7

0-100 index

Facility count

97.9 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+17.5

Compared with US county median

Named operators

AWSMicrosoft

Mapped facilities

Amazon
Amazon Data Services
OSM
Amazon AWS SAT - 12807 Donop
Amazon Web Services
OSM
CyrusOne San Antonio I
San Antonio · CyrusOne
OSM
CyrusOne San Antonio II
CyrusOne
OSM
CyrusOne San Antonio III
CyrusOne
OSM
CyrusOne San Antonio IV
CyrusOne
OSM

36 more mapped facilities included in the county score.

See the Bexar County data-center report Review methodology

Data Center Water Budget Calculator

Estimate daily water use for a hypothetical facility in Bexar County.

Facility size: 100 MW

1 MW1,000 MW

Cooling type

Utilization: 70%

40%100%

799K gallons/dayModerate Impact

Your facility would use 10.7% of this county's industrial water baseline — manageable but worth monitoring against drought trends.

10.7% of county industrial baseline6.65 Mgal/day remaining headroom

Based on USGS 2020 water-use data and EPA-standard cooling intensity constants. Not a substitute for site-specific water rights analysis.

Editorial analysis

Understanding Bexar County’s Water

Drinking Water Quality Overview

EPA SDWIS

Bexar County earns a B grade for drinking water quality, scoring 67.5 out of 100. Over the past five years, EPA SDWIS records 52 health-based violations — a pattern that public water utilities are required to disclose and correct.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T13:30:00.000-05:00) puts San Antonio Rv at 186.0 cfs — well below its long-term average at 33% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Bexar County has extensive coverage with 122 active monitoring sites with 65,822 recent measurements on record. Predominant monitoring categories include physical and organics, pesticide. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Bexar County

Water Verdict

Bexar County receives a fair water quality assessment with a grade of B and a score of 67.5 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring.

Violation Context

Bexar County has recorded 52 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 2.2 violations per 100,000 people served, this rate is relatively low compared to many U.S. counties.

Consumer Guidance

Tap water in Bexar County meets baseline safety standards, though the compliance record shows some violations worth watching. Bexar County's drinking-water compliance score is 67.5 out of 100. The violation rate for Bexar County is 2.2 per 100,000 people served. Running tap water for 30 seconds before drinking can reduce any localized lead exposure from household plumbing. Requesting your utility's most recent Consumer Confidence Report is the fastest way to identify which specific contaminants were flagged. With 122 active water-quality monitoring sites in Bexar County, data coverage is strong. A pipeline streamflow snapshot from the San Antonio Rv gauge is also available on this page.

Regional Context

Bexar County has better water quality than the average county in Texas. Its water score is 37.1 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Bexar County's water environment

Official EPA Resources for Bexar County

EPA How's My Waterway

Interactive watershed health data for Bexar County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Bexar County

Consumer Confidence Reports (TX)

Annual water quality reports from utilities in Texas

Past 5 years

Water Quality Monitoring

Monitoring Sites

122

Active in the past 5 years

Measurements Recorded

66K

65,822 total readings

Most Measured

Physical
Organics, Pesticide
Organics, Other

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

186cfs

May 14, 6:30 PM UTC

vs Long-Term Average

33%

Well below typical

Primary Streamgage

San Antonio Rv nr Elmendorf, TX

USGS site: 08181800
Drainage area: 1,743 sq mi
Long-term mean: 558 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

Free tool

Estimate Your Water Costs

Water Cost Estimate

Household size

3 people · ~225 gal/day

Filter type

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Bexar County:C — Moderate

Some violations or watershed impairment detected.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

Try the full calculator →

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Frequently Asked Questions

What is the water quality in Bexar County, Texas?

Bexar County, Texas has a drinking-water quality grade of B with a score of 67.5/100, based on EPA SDWIS compliance data. The county has 52 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.

Are there any water violations in Bexar County?

Bexar County has 52 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.

How much water-quality monitoring happens in Bexar County?

EPA's Water Quality Portal records 65,822 measurements from 122 monitoring sites in Bexar County over the past five years. The most frequently measured characteristic groups are Physical, Organics, Pesticide, Organics, Other. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.

What's happening with rivers in Bexar County right now?

Bexar County's primary USGS streamgage on the San Antonio Rv has a pipeline snapshot of 186 cubic feet per second — 33% of the long-term mean of 557.9 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.

How does Bexar County water compare to the Texas average?

Bexar County's SDWIS water quality score of 67.5/100 is higher than the Texas state average of 30.4. The average water quality grade across Texas is F, based on data from 254 counties with available SDWIS data.

Is tap water safe to drink in Bexar County?

Based on EPA SDWIS data, Bexar County has a water quality grade of B (67.5/100). This indicates good to excellent water quality with strong SDWIS compliance. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).

Why does Bexar County have so many water violations?

Bexar County has 52 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.

How does Bexar County rank for water quality in Texas?

Bexar County ranks #18 out of 254 counties in Texas by SDWIS water quality score (1 = best). With a score of 67.5/100, it falls in the top third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Fort Bend County

Texas

67.8

Water score

Denton County

Texas

66.8

Water score

Rockwall County

Texas

66.8

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated May 14, 2026Reviewed by Evan Brooks, Data Editor

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