17,609 people (2024 Census estimate, +0.9% since 2020)
578 square miles of land · 30 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 Delaware County in the area they serve, reporting 7,810 people served in all (a system that crosses county lines counts its whole population).
| MANCHESTER WATER SUPPLY groundwater · local government · IA2839021 | 5,077 served |
| EARLVILLE MUNI WATER SUPPLY groundwater · local government · IA2825099 | 724 served |
| HOPKINTON MUNICIPAL UTILITIES groundwater · local government · IA2835056 | 622 served |
| DELHI WATER SUPPLY groundwater · local government · IA2817020 | 420 served |
| COLESBURG WATER SUPPLY groundwater · local government · IA2809055 | 386 served |
| RYAN WATER SUPPLY groundwater · local government · IA2864013 | 350 served |
| DELAWARE MUNICIPAL WATER SUPPLY groundwater · local government · IA2813019 | 142 served |
| PENN CENTER INC groundwater · private · IA2800901 | 89 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 16 people were held in Delaware County's jail, in Vera's latest figure (2019), or 150 per 100,000 residents ages 15–64. In 2014 it was about 10.
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 Delaware County. School taxes are usually the largest part of a property tax bill.
Spent $45.9 million — $18.3 million to run schools, about $13,227 per student, plus $25.3 million on buildings and equipment. Money in: $10.5 million local (mostly property tax), $11.7 million state, $1.5 million federal. Long-term debt: $21.2 million.
Spent $11.2 million — $8.8 million to run schools, about $12,508 per student, plus $1.6 million on buildings and equipment. Money in: $5.5 million local (mostly property tax), $5.2 million state, $1 million federal. Long-term debt: $2.5 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 Delaware County about $17.1 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.
294 bridges in Delaware County: 114 in good condition, 160 fair, and 20 poor (6.8%). “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.
| W MARION ST over MAQUOKETA RIVER · built 1980 | 6,294 vehicles a day |
| 220 ST over BR ROBINSON CREEK · built 1922 | 1,061 vehicles a day |
| FM 197 AVE over SMALL STREAM · built 1967 | 962 vehicles a day |
| FM 130 AVE over SANDHAGEN CREEK · built 1965 | 825 vehicles a day |
| 170TH ST over PLUM CREEK · built 1949 | 275 vehicles a day |
| LOCAL PHEASANT over SMALL STREAM · built 1973 | 97 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $2.6 million of work in Delaware County in fiscal 2025, about $148 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 Delaware 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 Delaware County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Buchanan County (24 mi) · Dubuque County (25 mi) · Clayton County (25 mi) · Jones County (27 mi) · Linn County (30 mi) · Fayette County (36 mi).