14,856 people (2024 Census estimate, −1.0% since 2020)
577 square miles of land · 26 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.
9 active community water systems list Hamilton County in the area they serve, reporting 17,394 people served in all (a system that crosses county lines counts its whole population).
| WEBSTER CITY WATER SUPPLY groundwater · local government · IA4063094 | 7,825 served |
| XENIA RWD (NORTH) groundwater · private · IA9425701 | 6,122 served |
| JEWELL WATER SUPPLY groundwater · local government · IA4027010 | 1,216 served |
| STRATFORD MUNI WATER DEPT groundwater · local government · IA4051002 | 707 served |
| ELLSWORTH PUBLIC WATER SUPPLY groundwater · local government · IA4009016 | 514 served |
| STANHOPE WATER DEPARTMENT groundwater · local government · IA4045090 | 364 served |
| WILLIAMS WATER SUPPLY groundwater · local government · IA4070022 | 315 served |
| BLAIRSBURG WATER SUPPLY groundwater · local government · IA4003012 | 177 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.
About 15 people were held in Hamilton County's jail, in Vera's latest figure (2019), or 164 per 100,000 residents ages 15–64. In 2014 it was about 11.
Source: Vera Institute of Justice, Incarceration Trends (built from federal Bureau of Justice Statistics jail surveys). Counties without their own jail, or that share one, may show no figure.
3 school districts have their office in Hamilton County. School taxes are usually the largest part of a property tax bill.
Spent $26.9 million — $23.5 million to run schools, about $12,872 per student, plus $2.1 million on buildings and equipment. Money in: $12.5 million local (mostly property tax), $15.7 million state, $2.5 million federal. Long-term debt: $10.2 million.
Spent $10.7 million — $8.6 million to run schools, about $12,459 per student, plus $1 million on buildings and equipment. Money in: $7.5 million local (mostly property tax), $4.8 million state, $666,000 federal. Long-term debt: $7.4 million.
Spent $2.7 million — $1.6 million to run schools, about $20,500 per student, plus $151,000 on buildings and equipment. Money in: $1.6 million local (mostly property tax), $1.1 million state, $190,000 federal.
Source: U.S. Census Bureau, 2023 Annual Survey of School System Finances. Districts are listed by the county of their main office; some serve neighboring counties too.
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 Low compared with other U.S. counties. FEMA estimates natural hazards cost Hamilton County about $15.5 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively High; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
165 bridges in Hamilton County: 61 in good condition, 72 fair, and 32 poor (19.4%). “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.
| FM over SKUNK RIVER · built 1974 | 698 vehicles a day |
| VAIL AVE over OVER CC RR · built 1932 | 578 vehicles a day |
| PARK AVE over LYONS CREEK · built 1947 | 490 vehicles a day |
| FAS 3556 over CREEK · built 1947 | 478 vehicles a day |
| FM over SKUNK RIVER · built 1992 | 459 vehicles a day |
| FM over DRAINAGE DITCH · built 1960 | 319 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $1.9 million of work in Hamilton County in fiscal 2025, about $125 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.
Registration deadlines, early voting and polling places for Iowa are on the federal site vote.gov, which links to the state's official election office.
The budget, property tax rates, audits, local officials and offices for Hamilton 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 Hamilton County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Wright County (24 mi) · Hardin County (24 mi) · Webster County (24 mi) · Boone County (27 mi) · Story County (27 mi) · Franklin County (33 mi).