22,631 people (2024 Census estimate, +0.4% since 2020)
569 square miles of land · 40 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.
14 active community water systems list Washington County in the area they serve, reporting 31,684 people served in all (a system that crosses county lines counts its whole population).
| WAPELLO RURAL WATER ASSOC. buys surface water · private · IA9000742 | 17,263 served |
| WASHINGTON WATER DEPARTMENT groundwater · local government · IA9271068 | 7,362 served |
| KALONA WATER DEPT groundwater · local government · IA9233012 | 2,630 served |
| WELLMAN MUNICIPAL WATERWORKS groundwater · local government · IA9276096 | 1,524 served |
| RIVERSIDE WATER SUPPLY groundwater · local government · IA9260090 | 1,060 served |
| BRIGHTON MUNICIPAL WATER SUPPLY groundwater · local government · IA9209043 | 600 served |
| AINSWORTH WATER WORKS groundwater · local government · IA9203007 | 511 served |
| CRAWFORDSVILLE WATER SUPPLY buys groundwater · local government · IA9214085 | 277 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 55 people were held in Washington County's jail, in Vera's latest figure (2019), or 406 per 100,000 residents ages 15–64. In 2013 it was about 28.
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 Washington County. School taxes are usually the largest part of a property tax bill.
Spent $33.4 million — $25.5 million to run schools, about $15,239 per student, plus $5.5 million on buildings and equipment. Money in: $11.8 million local (mostly property tax), $15.5 million state, $3.9 million federal. Long-term debt: $25.5 million.
Spent $25.7 million — $19.3 million to run schools, about $13,373 per student, plus $5.3 million on buildings and equipment. Money in: $13.2 million local (mostly property tax), $10.9 million state, $1.9 million federal. Long-term debt: $5.9 million.
Spent $10.1 million — $7.1 million to run schools, about $12,598 per student, plus $1.7 million on buildings and equipment. Money in: $5.7 million local (mostly property tax), $4.6 million state, $504,000 federal. Long-term debt: $4.4 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 Washington County about $13.9 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.
207 bridges in Washington County: 82 in good condition, 92 fair, and 33 poor (15.9%). “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 WILLIAMS CREEK · built 1936 | 1,650 vehicles a day |
| B AVE over SMALL STREAM · built 1936 | 938 vehicles a day |
| 9TH AVENUE over SMITH CREEK · built 1928 | 920 vehicles a day |
| FM over N. FORK LONG CREEK · built 1961 | 440 vehicles a day |
| FM over SMALL STREAM · built 1925 | 270 vehicles a day |
| FM over N. FORK LONG CREEK · built 1925 | 160 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $2.7 million of work in Washington County in fiscal 2025, about $119 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 Washington 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 Washington County built: brayden.ozark@gmail.com.
More of Iowa: the state government and every county in Iowa.
Nearby counties: Keokuk County (23 mi) · Johnson County (25 mi) · Louisa County (25 mi) · Henry County (25 mi) · Jefferson County (26 mi) · Iowa County (30 mi).