666,918 people (2024 Census estimate, +1.8% since 2020)
798 square miles of land · 836 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.
30 active community water systems list Arapahoe County in the area they serve, reporting 865,342 people served in all (a system that crosses county lines counts its whole population).
| AURORA CITY OF surface water · local government · CO0103005 | 533,407 served |
| EAST CHERRY CREEK VALLEY WSD buys surface water · local government · CO0103035 | 66,130 served |
| ENGLEWOOD CITY OF surface water · local government · CO0103045 | 59,904 served |
| SOUTHGATE WSD buys surface water · local government · CO0103721 | 55,000 served |
| SOUTHWEST METROPOLITAN WSD buys surface water · local government · CO0103723 | 48,648 served |
| ARAPAHOE CNTY WWWA groundwater · private · CO0203002 | 31,000 served |
| PLATTE CANYON WSD buys surface water · local government · CO0103614 | 19,485 served |
| WILLOWS WD buys surface water · local government · CO0103100 | 19,000 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 888 people were held in Arapahoe County's jail, in Vera's latest figure (2025). In 2020 it was about 687.
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.
7 school districts have their office in Arapahoe County. School taxes are usually the largest part of a property tax bill.
Spent $950.3 million — $794.1 million to run schools, about $15,158 per student, plus $122.9 million on buildings and equipment. Money in: $452.3 million local (mostly property tax), $425.6 million state, $47.8 million federal. Long-term debt: $711.6 million.
Spent $871.2 million — $690.7 million to run schools, about $18,111 per student, plus $135.3 million on buildings and equipment. Money in: $371.4 million local (mostly property tax), $338.5 million state, $92.9 million federal. Long-term debt: $421.4 million.
Spent $348 million — $214.2 million to run schools, about $15,924 per student, plus $114 million on buildings and equipment. Money in: $170.7 million local (mostly property tax), $83.4 million state, $10.7 million federal. Long-term debt: $382.6 million.
Spent $56 million — $53.4 million to run schools, about $9,415 per student, plus $2 million on buildings and equipment. Money in: $4 million local (mostly property tax), $50.4 million state, $2 million federal.
Spent $56.9 million — $45.5 million to run schools, about $18,632 per student, plus $5 million on buildings and equipment. Money in: $42.6 million local (mostly property tax), $9.6 million state, $6.3 million federal. Long-term debt: $132.8 million.
Spent $34.4 million — $28.5 million to run schools, about $25,345 per student, plus $4.5 million on buildings and equipment. Money in: $13.1 million local (mostly property tax), $9.9 million state, $9.1 million federal. Long-term debt: $14.9 million.
Spent $4.9 million — $4.1 million to run schools, about $12,751 per student, plus $231,000 on buildings and equipment. Money in: $2.5 million local (mostly property tax), $2.9 million state, $403,000 federal. Long-term debt: $5.8 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 Moderate compared with other U.S. counties. FEMA estimates natural hazards cost Arapahoe County about $171.5 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively Moderate; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
392 bridges in Arapahoe County: 104 in good condition, 267 fair, and 21 poor (5.4%). “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.
| US 285 ML over LITTLE DRY CREEK · built 1955 | 46,000 vehicles a day |
| BROADWAY over LITTLE DRY CREEK · built 1935 | 31,496 vehicles a day |
| SH 177 ML over LITTLE DRY CREEK · built 1965 | 29,000 vehicles a day |
| SH 88 ML over BEAR CREEK · built 1966 | 21,000 vehicles a day |
| ALAMEDA AVE over I 225 ML · built 1969 | 20,060 vehicles a day |
| I 70 ML WBND over US 40 FRONTAGE RD · built 1965 | 10,527 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $-250,815,533 of work in Arapahoe County in fiscal 2025, about $-383 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.
General election: Tuesday, November 3, 2026. Ballots mailed to voters: 2026-10-02 to 2026-10-09. Drop boxes open: 2026-10-12. In-person voting at voter centers: 2026-10-19 to 2026-11-03. Last day to register and still get a ballot by mail: 2026-10-26. Last suggested day to mail your ballot back: 2026-10-26. Election Day: 2026-11-03. Last day to fix a signature problem: 2026-11-12.
Source: Colorado Secretary of State, Oct. 2, 2026 · Colorado Secretary of State, Sept. 23, 2026 · Colorado Secretary of State — Election Day FAQs
The budget, property tax rates, audits, local officials and offices for Arapahoe 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 Arapahoe County built: brayden.ozark@gmail.com.
More of Colorado: the state government and every county in Colorado.
Nearby counties: Adams County (16 mi) · Elbert County (26 mi) · Denver County (30 mi) · Douglas County (38 mi) · Broomfield County (44 mi) · Jefferson County (49 mi).