73,840 people (2024 Census estimate, +0.9% since 2020)
620 square miles of land · 119 people per square mile
“Highest” and “lowest” are just order, not grades: a high rank for poverty or hazard losses means more of it. Each figure's source is in its section below.
16 active community water systems list Kauai County in the area they serve, reporting 76,806 people served in all (a system that crosses county lines counts its whole population).
| LIHUE-KAPAA surface water · local government · HI0000400 | 34,854 served |
| KALAHEO-KOLOA groundwater · local government · HI0000434 | 12,660 served |
| PRINCEVILLE groundwater · private · HI0000428 | 6,911 served |
| KEKAHA-WAIMEA groundwater · local government · HI0000406 | 5,998 served |
| HANAPEPE-ELEELE groundwater · local government · HI0000404 | 5,592 served |
| KILAUEA groundwater · local government · HI0000407 | 3,420 served |
| ANAHOLA groundwater · local government · HI0000401 | 2,473 served |
| GAY & ROBINSON groundwater · private · HI0000417 | 1,271 served |
Source: U.S. EPA Safe Drinking Water Information System (SDWIS), active community systems, . Look up any system's violations and test results with EPA's search using its ID.
No county jail figure in the national data for Kauai County — not gathered, never hidden. Some counties share a regional jail or have none.
Source: County Health Rankings & Roadmaps 2025 (University of Wisconsin Population Health Institute), which gathers federal data (CDC, Census, and others); measures cover different recent years. Blank lines aren't reported for small counties.
Overall risk: Relatively Moderate compared with other U.S. counties. FEMA estimates natural hazards cost Kauai County about $60.9 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
85 bridges in Kauai County: 23 in good condition, 56 fair, and 6 poor (7.1%). “Poor” means a main part — the deck, the beams, or the supports — is rated 4 or lower on the federal 0–9 scale. It doesn't mean unsafe to drive; unsafe bridges are closed.
| KUHIO HWY over WAILUA RIVER · built 1945 | 31,600 vehicles a day |
| KUHIO HWY over KALIHIWAI RIVER · built 1963 | 15,500 vehicles a day |
| KOLOA RD over Waikomo Stream · built 1928 | 12,108 vehicles a day |
| Lawai Road over Kukuiula Bay · built 1993 | 500 vehicles a day |
| KIPU RD over HULEIA STRM(KIPU BR) · built 1914 | 200 vehicles a day |
| KOOLAU RD over WAIPAKE STRM(KIAKI BR) · built 1921 | 90 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $102.1 million of work in Kauai County in fiscal 2025, about $1,393 per resident — to the county, cities, schools, hospitals, nonprofits and others.
Source: USAspending.gov, grants by place of performance, fiscal 2025 (Oct. 2024 to Sept. 2025). Search it by county to see each award.
From Grants.gov: posted grants listing county governments as eligible, soonest deadline first; research-only and overseas programs left out; list updated 2026-10-13, refreshed weekly. 62 are open in all. Cities, towns, school districts and nonprofits have their own lists there.
General election: Tuesday, November 3, 2026. Mail ballots arrive: 2026-10-16. Voter service centers open: 2026-10-20 to 2026-11-03. Paper registration deadline: 2026-10-26. Last day to ask for your ballot at a different address: 2026-10-27. Election Day: 2026-11-03.
Source: Hawaii Office of Elections, 2026 General Election Voter Guide · Hawaii Office of Elections, Voting in Hawaii · Hawaii Office of Elections, Voter Service Centers and Ballot Drop Boxes
The budget, property tax rates, audits, local officials and offices for Kauai County come from the county's own records, which we haven't gathered — not gathered, never hidden. See what a full county site looks like, or ask to have Kauai County built: brayden.ozark@gmail.com.
More of Hawaii: the state government and every county in Hawaii.
Nearby counties: Honolulu County (103 mi) · Kalawao County (183 mi) · Maui County (214 mi) · Hawaii County (316 mi) · Aleutians East Borough, AK (2298 mi) · Kodiak Island Borough, AK (2490 mi).