12,405 people (2024 Census estimate, +0.5% since 2020)
502 square miles of land · 25 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 Grundy County in the area they serve, reporting 46,025 people served in all (a system that crosses county lines counts its whole population).
| IA REGIONAL UTILITIES ASSOC (WAVERLY) groundwater · private · IA0990701 | 37,820 served |
| GRUNDY CENTER WATER SUPPLY buys groundwater · local government · IA3833013 | 2,796 served |
| REINBECK WATER SUPPLY groundwater · local government · IA3870073 | 1,662 served |
| DIKE WATER SUPPLY buys groundwater · local government · IA3815042 | 1,306 served |
| CONRAD WATER SUPPLY buys groundwater · local government · IA3809067 | 1,098 served |
| WELLSBURG WATER SUPPLY buys groundwater · local government · IA3890097 | 721 served |
| HOLLAND WATER SUPPLY buys groundwater · local government · IA3839052 | 270 served |
| STOUT WATER SUPPLY groundwater · local government · IA3880001 | 191 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 2 people were held in Grundy County's jail, in Vera's latest figure (2019), or 27 per 100,000 residents ages 15–64. In 2014 it was about 5.
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.
4 school districts have their office in Grundy County. School taxes are usually the largest part of a property tax bill.
Spent $18.1 million — $12.8 million to run schools, about $13,499 per student, plus $4.5 million on buildings and equipment. Money in: $6.6 million local (mostly property tax), $7.7 million state, $833,000 federal. Long-term debt: $18.2 million.
Spent $11.7 million — $9.4 million to run schools, about $12,215 per student, plus $1.5 million on buildings and equipment. Money in: $6.1 million local (mostly property tax), $5.7 million state, $827,000 federal. Long-term debt: $12.6 million.
Spent $8.6 million — $7.2 million to run schools, about $14,322 per student, plus $906,000 on buildings and equipment. Money in: $4.5 million local (mostly property tax), $3.7 million state, $595,000 federal. Long-term debt: $149,000.
Spent $9 million — $6.7 million to run schools, about $13,361 per student, plus $983,000 on buildings and equipment. Money in: $4.3 million local (mostly property tax), $5 million state, $578,000 federal. Long-term debt: $255,000.
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 Grundy County about $9.5 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
288 bridges in Grundy County: 120 in good condition, 91 fair, and 77 poor (26.7%). “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 14 over BLACK HAWK CREEK · built 1931 | 3,230 vehicles a day |
| FM over BLACKHAWK CREEK · built 1971 | 1,935 vehicles a day |
| FIRST ST over BLACKHAWK CREEK · built 1977 | 1,429 vehicles a day |
| FIRST ST over BLACKHAWK CREEK · built 1977 | 1,429 vehicles a day |
| FM over WOLF CREEK BRANCH · built 1975 | 1,394 vehicles a day |
| FM over CREEK · built 1966 | 707 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $2.8 million of work in Grundy County in fiscal 2025, about $224 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 Grundy 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 Grundy County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Butler County (23 mi) · Hardin County (23 mi) · Black Hawk County (25 mi) · Tama County (26 mi) · Marshall County (27 mi) · Franklin County (34 mi).