County water report

Clark County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Clark County, Nevada.

Water grade

Water score

64.4

State rank

of 16

Health violations

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

2,386 recent measurements

Live streamflow

No gauge

COLORADO RV BLW HOOVER DAM, AZ-NV

Water at a glance

Key Water Indicators for Clark County

EPA SDWIS

Safety Grade

Score: 64.4 / 100

EPA SDWIS

Active Violations

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

No gauge

COLORADO RV BLW HOOVER DAM, AZ-NV

EPA WQP

Monitoring Sites

2,386 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.

64.4/100

Health violations

Health-based violations

Violations per 100K served

3.9

Population-normalized SDWIS rate

Data center water stress

Clark County has 26 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #47 nationally by combining its water score with mapped data center density.

DCWSI

76.4

0-100 index

Facility count

94.5 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+14.4

Compared with US county median

Named operators

Google

Mapped facilities

CenturyLink
Lumen Technologies
OSM
CenturyLink
Facility details limited
OSM
DataBank Las Vegas LAS1
Las Vegas · DataBank
OSM
Fiberhub LAS1
Las Vegas · Fiberhub
OSM
Flexential Las Vegas - Downtown
Las Vegas · Flexential
OSM
Flexential Las Vegas - North
North Las Vegas · Flexential
OSM

20 more mapped facilities included in the county score.

See the Clark County data-center report Review methodology

Data Center Water Budget Calculator

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

Facility size: 100 MW

1 MW1,000 MW

Cooling type

Utilization: 70%

40%100%

799K gallons/dayHigh Impact

Your facility would use 23.9% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

23.9% of county industrial baseline2.54 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 Clark County’s Water

Drinking Water Quality Overview

EPA SDWIS

Clark County earns a B grade for drinking water quality, scoring 64.4 out of 100. Over the past five years, EPA SDWIS records 92 health-based violations — a pattern that public water utilities are required to disclose and correct.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Clark County has moderate coverage with 46 active monitoring sites with 2,386 recent measurements on record. Predominant monitoring categories include inorganics, minor, metals 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 Clark County

Water Verdict

Clark County, Nevada receives a fair water quality assessment with a grade of B and a score of 64.4 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring. The county's primary USGS gauge drains roughly 171,700 square miles of upstream watershed, giving local source waters a regional footprint.

Violation Context

EPA SDWIS records for Clark County, Nevada show 92 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 3.9 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges. For independent context, 2,386 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Tap water in Clark County meets baseline safety standards, though the compliance record shows some violations worth watching. Clark County's drinking-water compliance score is 64.4 out of 100. The violation rate for Clark County is 3.9 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 46 active water-quality monitoring sites in Clark County, data coverage is strong. A pipeline streamflow snapshot from the COLORADO RV BLW HOOVER DAM, AZ-NV gauge is also available on this page.

Regional Context

Clark County has better water quality than the average county in Nevada. Its water score is 15.9 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 Clark County's water environment

Official EPA Resources for Clark County

EPA How's My Waterway

Interactive watershed health data for Clark County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Clark County

Consumer Confidence Reports (NV)

Annual water quality reports from utilities in Nevada

Past 5 years

Water Quality Monitoring

Monitoring Sites

Active in the past 5 years

Measurements Recorded

2.4K

2,386 total readings

Most Measured

Inorganics, Minor, Metals
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).

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 Clark 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 →

Improve your water quality at home

Berkey filters remove 99.9%+ of contaminants from tap water.

Shop Berkey →

Test your tap water

Tap Score provides professional mail-in water testing.

Get Tested →

Frequently Asked Questions

What is the water quality in Clark County, Nevada?

Clark County, Nevada has a drinking-water quality grade of B with a score of 64.4/100, based on EPA SDWIS compliance data. The county has 92 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 Clark County?

Clark County has 92 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 Clark County?

EPA's Water Quality Portal records 2,386 measurements from 46 monitoring sites in Clark County over the past five years. The most frequently measured characteristic groups are Inorganics, Minor, Metals, 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.

How does Clark County water compare to the Nevada average?

Clark County's SDWIS water quality score of 64.4/100 is higher than the Nevada state average of 48.5. The average water quality grade across Nevada is D, based on data from 16 counties with available SDWIS data.

Is tap water safe to drink in Clark County?

Based on EPA SDWIS data, Clark County has a water quality grade of B (64.4/100). 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 Clark County have so many water violations?

Clark County has 92 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 Clark County rank for water quality in Nevada?

Clark County ranks #5 out of 16 counties in Nevada by SDWIS water quality score (1 = best). With a score of 64.4/100, 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

White Pine County

Nevada

52.9

Water score

Lyon County

Nevada

47.3

Water score

Mineral County

Nevada

43.5

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.

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

Explore more data for Clark County

Property Tax Cost of Living Crime Rate Income Health Schools Disaster Risk Weather County Score