17,161 people (2024 Census estimate, +3.2% since 2020)
561 square miles of land · 31 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.
5 active community water systems list Madison County in the area they serve, reporting 48,287 people served in all (a system that crosses county lines counts its whole population).
| SIRWA #2 (CRESTON) surface water · private · IA8080701 | 20,793 served |
| WARREN WATER DISTRICT buys surface water · private · IA9133701 | 20,095 served |
| WINTERSET MUNICIPAL WATERWORKS surface water · local government · IA6171029 | 5,428 served |
| EARLHAM MUNICIPAL WATERWORKS buys surface water · local government · IA6115097 | 1,446 served |
| TRURO WATERWORKS buys surface water · local government · IA6167036 | 525 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 11 people were held in Madison County's jail, in Vera's latest figure (2019), or 106 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 Madison County. School taxes are usually the largest part of a property tax bill.
Spent $24.9 million — $20.7 million to run schools, about $12,275 per student, plus $2.3 million on buildings and equipment. Money in: $13.5 million local (mostly property tax), $15 million state, $1.5 million federal. Long-term debt: $25.1 million.
Spent $13.9 million — $11.4 million to run schools, about $13,504 per student, plus $1.1 million on buildings and equipment. Money in: $7.2 million local (mostly property tax), $7.8 million state, $702,000 federal. Long-term debt: $9.2 million.
Spent $8.2 million — $7.2 million to run schools, about $11,283 per student, plus $460,000 on buildings and equipment. Money in: $4.2 million local (mostly property tax), $4.8 million state, $383,000 federal. Long-term debt: $2.3 million.
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: Very Low compared with other U.S. counties. FEMA estimates natural hazards cost Madison County about $10.3 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively Moderate.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
225 bridges in Madison County: 38 in good condition, 105 fair, and 82 poor (36.4%). “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 BR BADGER CREEK · built 1970 | 1,714 vehicles a day |
| FM over BADGER CREEK · built 1956 | 1,404 vehicles a day |
| FM over OVER-FLOW-NORTH RIVER · built 1970 | 880 vehicles a day |
| FM over JONES CREEK · built 1929 | 788 vehicles a day |
| FM over JIM CREEK · built 1948 | 668 vehicles a day |
| FM over DRAINAGE · built 1949 | 597 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $3.2 million of work in Madison County in fiscal 2025, about $196 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 Madison 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 Madison County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Warren County (23 mi) · Clarke County (24 mi) · Adair County (24 mi) · Union County (24 mi) · Dallas County (25 mi) · Polk County (34 mi).