Hawaii
Hawaii sits in the Pacific and draws its water primarily from volcanic aquifers and rainfall catchment. With roughly 1.44 million residents, the state has a developing water reuse program, reusing an estimated 12% of its treated wastewater.
Hawaiiwater quality & safety
Top violation drivers in Hawaii
| Contaminant / rule | Systems |
|---|---|
| LEAD AND COPPER RULE REVISIONS | 3 |
| Surface Water Treatment Rule | 2 |
| TTHM | 1 |
| Revised Total Coliform Rule | 1 |
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1 · health-based violations since 2016
Island aquifers are the primary supply and are sensitive to both over-pumping and contamination, as the Red Hill fuel crisis underscored.
On the U.S. Drought Monitor scale, Hawaii currently tracks around no drought conditions. Hawaii has 117 community water systems serving about 2 million people; EPA records show 7 of them (6%) 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 Hawaii 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)
- 194 gpcd
- Total withdrawals
- 1.1 Bgal/d
- From groundwater
- 49.6%
- Irrigation share
- 36.3%
- Wastewater reused (est.)
- ~12%
Primary water sources
- ≈ volcanic aquifers
- ≈ rainfall catchment
Common questions
Is tap water safe in Hawaii?
Hawaii has 117 community water systems serving about 2 million people. EPA records show 7 of them (6%) with at least one health-based Safe Drinking Water Act violation since 2016, and 0 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 Hawaii's water?
The most frequent health-based violations involve LEAD AND COPPER RULE REVISIONS, Surface Water Treatment Rule, TTHM.
How much water does Hawaii use per person?
Public water systems in Hawaii withdraw about 194 gallons per person per day (USGS 2015), drawing 49.6% of fresh water from groundwater.
How bad is the drought in Hawaii?
As of 2026-06-09, 0% of Hawaii is in drought (D1+) and 0% is in severe drought or worse, per the U.S. Drought Monitor.
Cities in Hawaii
6 trackedHonolulu
Honolulu, HI water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
East Honolulu
East Honolulu, HI water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
Pearl City
Pearl City, HI water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
Hilo
Hilo, HI water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
Kailua
Kailua, HI water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
Waipahu
Waipahu, HI water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
Key issues in Hawaii
Groundwater Depletion
Aquifers from the Central Valley to the Ogallala are being pumped faster than they recharge, causing land subsidence and threatening long-term supply.
ExploreSaltwater Intrusion
As coastal aquifers are over-pumped and seas rise, saltwater pushes inland and contaminates freshwater supplies for cities from Florida to California.
ExplorePotable Reuse
Advanced purification turns treated wastewater into water that meets or exceeds drinking-water standards — increasingly essential in water-stressed regions.
Explore