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County water report

San Patricio County Water Report

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

Water grade

F

Water score

23.6

State rank

#130

of 254

Health violations

66

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

4

816 recent measurements

Live streamflow

5%

Nueces Rv nr Mathis, TX

Water at a glance

Key Water Indicators for San Patricio County

EPA SDWIS

Safety Grade

F

Score: 23.6 / 100

EPA SDWIS

Active Violations

66

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

5% of mean

Nueces Rv nr Mathis, TX

EPA WQP

Monitoring Sites

4

816 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

F

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

23.6/100

Health violations

66

Health-based violations

Violations per 100K served

97.7

Population-normalized SDWIS rate

Editorial analysis

Understanding San Patricio County’s Water

Drinking Water Quality Overview

EPA SDWIS

San Patricio County's water systems carry a failing grade, scoring 23.6 out of 100. Over the past five years, EPA SDWIS records 66 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 2026-05-14T14:00:00.000-05:00) puts Nueces Rv at 30.0 cfs — well below its long-term average at 5% 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. San Patricio County has limited coverage with 4 active monitoring sites with 816 recent measurements on record. Predominant monitoring categories include microbiological and physical. 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 San Patricio County

Water Verdict

San Patricio County receives a poor water quality assessment with a grade of F and a score of 23.6 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans.

Violation Context

San Patricio County has recorded 66 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 97.7 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

San Patricio County has a Grade F compliance record with 66 health-based violations — among the highest levels in the country. San Patricio County's drinking-water compliance score is 23.6 out of 100. The violation rate for San Patricio County is 97.7 per 100,000 people served. Residents are strongly advised to use a certified NSF 58 reverse-osmosis filter or bottled water for all drinking and cooking until violations are corrected. Contacting the Texas Department of Environmental Quality or Health can expedite utility compliance action. There are 4 active water-quality monitoring sites in San Patricio County. A pipeline streamflow snapshot from the Nueces Rv gauge is also available on this page.

Regional Context

San Patricio County has poorer water quality than the average county in Texas. Its water score is 6.8 points lower than the state average, suggesting more challenges with contamination control or infrastructure than 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 San Patricio County's water environment

Official EPA Resources for San Patricio County

EPA How's My Waterway

Interactive watershed health data for San Patricio County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for San Patricio County

Consumer Confidence Reports (TX)

Annual water quality reports from utilities in Texas

Past 5 years

Water Quality Monitoring

Monitoring Sites

4

Active in the past 5 years

Measurements Recorded

816

816 total readings

Most Measured

  • Microbiological
  • Physical
  • Nutrient

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

30.0cfs

May 14, 7:00 PM UTC

vs Long-Term Average

5%

Well below typical

Primary Streamgage

Nueces Rv nr Mathis, TX

USGS site
08211000
Drainage area
16,503 sq mi
Long-term mean
626 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

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for San Patricio County:F — Failing

High violation count or severe watershed conditions.

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.

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Frequently Asked Questions

What is the water quality in San Patricio County, Texas?
San Patricio County, Texas has a drinking-water quality grade of F with a score of 23.6/100, based on EPA SDWIS compliance data. The county has 66 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 San Patricio County?
San Patricio County has 66 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 San Patricio County?
EPA's Water Quality Portal records 816 measurements from 4 monitoring sites in San Patricio County over the past five years. The most frequently measured characteristic groups are Microbiological, Physical, Nutrient. 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 San Patricio County right now?
San Patricio County's primary USGS streamgage on the Nueces Rv has a pipeline snapshot of 30 cubic feet per second — 5% of the long-term mean of 626.26 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 San Patricio County water compare to the Texas average?
San Patricio County's SDWIS water quality score of 23.6/100 is lower 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 San Patricio County?
Based on EPA SDWIS data, San Patricio County has a water quality grade of F (23.6/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. 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 San Patricio County have so many water violations?
San Patricio County has 66 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 San Patricio County rank for water quality in Texas?
San Patricio County ranks #130 out of 254 counties in Texas by SDWIS water quality score (1 = best). With a score of 23.6/100, it falls in the middle 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

Comal County

Texas

F

23.6

Water score

Randall County

Texas

F

23.0

Water score

Bandera County

Texas

F

24.3

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 Reviewed by Evan Brooks, Data Editor

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