AGUACYCLE
West · ID

Idaho

Exceptional (D4)Developing reuse

Idaho sits in the West and draws its water primarily from Snake River, Snake River Plain aquifer, and snowpack. With roughly 1.96 million residents, the state has a developing water reuse program, reusing an estimated 9% of its treated wastewater.

Systems in violationhealth-based, since 2016
219 gpcd
Per capita use
Exceptional (D4)
Drought
774
Water systems
2M
People served

Idahowater quality & safety

774
Community water systems
251
With a health violation (32.4%)
291
With unresolved violations
10
Over the lead action level

Top violation drivers in Idaho

Contaminant / ruleSystems
Revised Total Coliform Rule95
Groundwater Rule74
LEAD AND COPPER RULE REVISIONS60
Lead and Copper Rule18
Arsenic15
Surface Water Treatment Rule12

Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1 · health-based violations since 2016

Intensive irrigation gives Idaho some of the highest per-capita withdrawals in the nation; aquifer recharge is a growing focus.

On the U.S. Drought Monitor scale, Idaho currently tracks around exceptional conditions. Idaho has 774 community water systems serving about 2 million people; EPA records show 251 of them (32.4%) with a health-based Safe Drinking Water Act violation since 2016. The pages below break down the water issues that matter most here and the communities working on solutions.

Drought history — severe+ extent

% of Idaho in severe drought or worse (D2+) each late summer.

Source: U.S. Drought Monitor (NDMC/UNL, USDA, NOAA) · latest 2026-06-09

Water use (USGS 2015)

Per-capita (public supply)
219 gpcd
Total withdrawals
17.7 Bgal/d
From groundwater
30.2%
Irrigation share
86.2%
Wastewater reused (est.)
~9%

Source: USGS Estimated Use of Water, 2015

Primary water sources

  • Snake River
  • Snake River Plain aquifer
  • snowpack

Common questions

Is tap water safe in Idaho?

Idaho has 774 community water systems serving about 2 million people. EPA records show 251 of them (32.4%) with at least one health-based Safe Drinking Water Act violation since 2016, and 10 system(s) over the federal lead action level. Most large systems meet standards; check your specific city and your utility's annual report.

What contaminants are most common in Idaho's water?

The most frequent health-based violations involve Revised Total Coliform Rule, Groundwater Rule, LEAD AND COPPER RULE REVISIONS.

How much water does Idaho use per person?

Public water systems in Idaho withdraw about 219 gallons per person per day (USGS 2015), drawing 30.2% of fresh water from groundwater.

How bad is the drought in Idaho?

As of 2026-06-09, 85.5% of Idaho is in drought (D1+) and 54.5% is in severe drought or worse, per the U.S. Drought Monitor.

Cities in Idaho

6 tracked

Key issues in Idaho

Analysis featuring Idaho