8,429 people (2024 Census estimate, −3.6% since 2020)
694 square miles of land · 12 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.
8 active community water systems list Monona County in the area they serve, reporting 5,791 people served in all (a system that crosses county lines counts its whole population).
| ONAWA MUNICIPAL WATER PLANT groundwater · local government · IA6739095 | 2,906 served |
| MAPLETON MUNICIPAL WATER PLANT groundwater · local government · IA6727028 | 1,124 served |
| WHITING WATER SUPPLY groundwater · local government · IA6769018 | 727 served |
| UTE WATER SUPPLY groundwater · local government · IA6762043 | 338 served |
| BLENCOE MUNICIPAL WATERWORKS groundwater · local government · IA6709017 | 224 served |
| MOORHEAD WATER SUPPLY groundwater · local government · IA6731006 | 189 served |
| SOLDIER WATER SUPPLY groundwater · local government · IA6749061 | 180 served |
| CASTANA MUNICIPAL WATER SUPPLY groundwater · local government · IA6715083 | 103 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 30 people were held in Monona County's jail, in Vera's latest figure (2019), or 589 per 100,000 residents ages 15–64. In 2014 it was about 6.
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 Monona County. School taxes are usually the largest part of a property tax bill.
Spent $11.4 million — $9.6 million to run schools, about $14,655 per student, plus $1.1 million on buildings and equipment. Money in: $5.4 million local (mostly property tax), $4.7 million state, $652,000 federal.
Spent $9.8 million — $8.2 million to run schools, about $12,885 per student, plus $965,000 on buildings and equipment. Money in: $5.6 million local (mostly property tax), $5.2 million state, $1 million federal. Long-term debt: $3.9 million.
Spent $3.9 million — $3 million to run schools, about $17,718 per student, plus $339,000 on buildings and equipment. Money in: $2.1 million local (mostly property tax), $1.5 million state, $390,000 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: Very Low compared with other U.S. counties. FEMA estimates natural hazards cost Monona County about $8.7 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.
160 bridges in Monona County: 60 in good condition, 59 fair, and 41 poor (25.6%). “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.
| IA 175 over I-29 · built 1959 | 4,090 vehicles a day |
| IA 141 & 175 over MAPLE RIVER · built 1967 | 3,720 vehicles a day |
| FM over DIVERSION DITCH · built 1962 | 597 vehicles a day |
| FM over DD · built 1959 | 597 vehicles a day |
| FM over FAMERS GARRETSON DITCH · built 1962 | 578 vehicles a day |
| FM over SOLDIER RIVER · built 1955 | 349 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $6.6 million of work in Monona County in fiscal 2025, about $758 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 Monona 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 Monona County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Burt County, NE (24 mi) · Woodbury County (24 mi) · Harrison County (26 mi) · Crawford County (29 mi) · Thurston County, NE (30 mi) · Ida County (33 mi).