99,242 people (2024 Census estimate, −0.1% since 2020)
608 square miles of land · 163 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.
32 active community water systems list Dubuque County in the area they serve, reporting 83,775 people served in all (a system that crosses county lines counts its whole population).
| DUBUQUE WATER WORKS groundwater · local government · IA3126052 | 59,667 served |
| ASBURY MUNICIPAL WATER SYSTEM groundwater · local government · IA3102001 | 5,943 served |
| DYERSVILLE MUNICIPAL WATER CO groundwater · local government · IA3130091 | 4,477 served |
| CASCADE MUNICIPAL WATER SUPPLY groundwater · local government · IA3118080 | 2,386 served |
| PEOSTA WATER SUPPLY groundwater · local government · IA3170001 | 2,278 served |
| EPWORTH WATER SUPPLY groundwater · local government · IA3133033 | 2,023 served |
| FARLEY WATER SUPPLY groundwater · local government · IA3135018 | 1,766 served |
| ALPINE PARK buys groundwater · private · IA3126605 | 932 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 162 people were held in Dubuque County's jail, in Vera's latest figure (2019), or 260 per 100,000 residents ages 15–64. In 2014 it was about 128.
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.
2 school districts have their office in Dubuque County. School taxes are usually the largest part of a property tax bill.
Spent $167.7 million — $145.2 million to run schools, about $13,808 per student, plus $16.8 million on buildings and equipment. Money in: $68.4 million local (mostly property tax), $92.6 million state, $13.5 million federal. Long-term debt: $82.3 million.
Spent $52.7 million — $44.3 million to run schools, about $11,836 per student, plus $6.6 million on buildings and equipment. Money in: $27.6 million local (mostly property tax), $27 million state, $3 million federal. Long-term debt: $24.8 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: Relatively Low compared with other U.S. counties. FEMA estimates natural hazards cost Dubuque County about $41.7 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.
346 bridges in Dubuque County: 180 in good condition, 141 fair, and 25 poor (7.2%). “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.
| 3RD AVE SW over N FORK MAQUOKETA RIVER · built 1967 | 1,651 vehicles a day |
| LOCAL over SOUTH FORK CATFISH CREEK · built 1926 | 756 vehicles a day |
| FM over SMALL · built 1996 | 540 vehicles a day |
| WILDWOOD DR over BEE BRANCH · built 1970 | 537 vehicles a day |
| LOCAL over CATFISH CREEK · built 1980 | 530 vehicles a day |
| DYERSVILLE EAST RD over CREEK · built 1964 | 511 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $44.1 million of work in Dubuque County in fiscal 2025, about $445 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 Dubuque 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 Dubuque County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Delaware County (25 mi) · Jackson County (26 mi) · Jones County (26 mi) · Grant County, WI (30 mi) · Clayton County (35 mi) · Jo Daviess County, IL (35 mi).