County water report

Collin County Water Report

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

Water grade

Water score

70.8

State rank

#16

of 254

Health violations

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

62,414 recent measurements

Live streamflow

128%

E Fk Trinity Rv nr Lavon, TX

Water at a glance

Key Water Indicators for Collin County

EPA SDWIS

Safety Grade

Score: 70.8 / 100

EPA SDWIS

Active Violations

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

128% of mean

E Fk Trinity Rv nr Lavon, TX

EPA WQP

Monitoring Sites

62,414 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.

70.8/100

Health violations

Health-based violations

Violations per 100K served

0.6

Population-normalized SDWIS rate

Data center water stress

Collin County has 18 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #35 nationally by combining its water score with mapped data center density.

DCWSI

79.4

0-100 index

Facility count

92.4 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+20.8

Compared with US county median

Named operators

Aligned Data CentersCyrusOneDataBankCentersquareFlexential

Mapped facilities

Aligned Data Centers
Plano · Aligned Data Centers
OSM
Cisco Allen
Facility details limited
OSM
CyrusOne Allen
CyrusOne
OSM
DATABANK DFW3
PLANO · DataBank
EPA ECHO
DATABANK DFW3
PLANO · DataBank
EPA CWA
DataBank Plano Data Center
Plano · DataBank
OSM

12 more mapped facilities included in the county score.

See the Collin County data-center report Review methodology

Data Center Water Budget Calculator

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

Facility size: 100 MW

1 MW1,000 MW

Cooling type

Utilization: 70%

40%100%

799K gallons/dayHigh Impact

Your facility would use 68.4% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

68.4% of county industrial baseline0.37 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 Collin County’s Water

Drinking Water Quality Overview

EPA SDWIS

Collin County earns an A grade for drinking water quality, scoring 70.8 out of 100. Over the past five years, EPA SDWIS records 8 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 E Fk Trinity Rv at 416.0 cfs — flowing above its historical average at 128% of mean. 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. Collin County has extensive coverage with 93 active monitoring sites with 62,414 recent measurements on record. Predominant monitoring categories include physical and inorganics, major, non-metals. 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 Collin County

Water Verdict

Collin County receives a good water quality assessment with a grade of A and a score of 70.8 out of 100. While the water supply is generally safe, occasional monitoring gaps or minor contaminant detections may occur.

Violation Context

Collin County has recorded 8 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 0.6 violations per 100,000 people served, this rate is relatively low compared to many U.S. counties.

Consumer Guidance

Tap water compliance data for Collin County shows a A grade. Collin County's drinking-water compliance score is 70.8 out of 100. Reviewing your utility's most recent Consumer Confidence Report provides the most accurate picture of detected contaminants and treatment status. An NSF-certified water filter can add an extra layer of safety for any household concerns. A pipeline streamflow snapshot from the E Fk Trinity Rv gauge is also available on this page.

Regional Context

Collin County has better water quality than the average county in Texas. Its water score is 40.4 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 Collin County's water environment

Official EPA Resources for Collin County

EPA How's My Waterway

Interactive watershed health data for Collin County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Collin County

Consumer Confidence Reports (TX)

Annual water quality reports from utilities in Texas

Past 5 years

Water Quality Monitoring

Monitoring Sites

Active in the past 5 years

Measurements Recorded

62K

62,414 total readings

Most Measured

Physical
Inorganics, Major, Non-metals
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

416cfs

May 14, 7:00 PM UTC

vs Long-Term Average

128%

Above typical

Primary Streamgage

E Fk Trinity Rv nr Lavon, TX

USGS site: 08061000
Drainage area: 773 sq mi
Long-term mean: 325 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 Collin 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 Collin County, Texas?

Collin County, Texas has a drinking-water quality grade of A with a score of 70.8/100, based on EPA SDWIS compliance data. The county has 8 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 Collin County?

Collin County has 8 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 Collin County?

EPA's Water Quality Portal records 62,414 measurements from 93 monitoring sites in Collin County over the past five years. The most frequently measured characteristic groups are Physical, Inorganics, Major, Non-metals, 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 Collin County right now?

Collin County's primary USGS streamgage on the E Fk Trinity Rv has a pipeline snapshot of 416 cubic feet per second — 128% of the long-term mean of 324.93 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.

How does Collin County water compare to the Texas average?

Collin County's SDWIS water quality score of 70.8/100 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 Collin County?

Based on EPA SDWIS data, Collin County has a water quality grade of A (70.8/100). 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 Collin County have so many water violations?

Collin County has 8 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 Collin County rank for water quality in Texas?

Collin County ranks #16 out of 254 counties in Texas by SDWIS water quality score (1 = best). With a score of 70.8/100, 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

Potter County

Texas

71.1

Water score

Dallas County

Texas

71.8

Water score

Fort Bend County

Texas

67.8

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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