2,340,211 people (2024 Census estimate, +2.9% since 2020)
2,116 square miles of land · 1,106 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.
156 active community water systems list King County in the area they serve, reporting 3,260,554 people served in all (a system that crosses county lines counts its whole population).
| SEATTLE PUBLIC UTILITIES surface water · local government · WA5377050 | 1,161,961 served |
| BELLEVUE CITY OF buys surface water · local government · WA5305575 | 321,349 served |
| KENT WATER DEPARTMENT buys surface water · local government · WA5338150 | 166,421 served |
| REDMOND WATER SYSTEM CITY OF buys surface water · local government · WA5371650 | 163,335 served |
| LAKEHAVEN WATER AND SEWER DISTRICT buys surface water · local government · WA5341997 | 148,809 served |
| RENTON CITY OF groundwater · local government · WA5371850 | 108,091 served |
| Auburn City of groundwater · local government · WA5303350 | 107,655 served |
| HIGHLINE WATER DISTRICT buys surface water · local government · WA5340650 | 100,170 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 1,326 people were held in King County's jail, in Vera's latest figure (2024), or 84 per 100,000 residents ages 15–64. In 2019 it was about 2,852.
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.
18 school districts have their office in King County. School taxes are usually the largest part of a property tax bill.
Spent $1.4 billion — $1.1 billion to run schools, about $21,806 per student, plus $278.9 million on buildings and equipment. Money in: $603.9 million local (mostly property tax), $716.2 million state, $77.7 million federal. Long-term debt: $15.3 million.
Spent $617.5 million — $528.5 million to run schools, about $17,053 per student, plus $56.9 million on buildings and equipment. Money in: $250.2 million local (mostly property tax), $395.4 million state, $14.6 million federal. Long-term debt: $571 million.
Spent $537.1 million — $491.2 million to run schools, about $19,199 per student, plus $34.3 million on buildings and equipment. Money in: $153.8 million local (mostly property tax), $353.6 million state, $68.7 million federal. Long-term debt: $234.6 million.
Spent $493.9 million — $386.7 million to run schools, about $17,898 per student, plus $79.1 million on buildings and equipment. Money in: $96.1 million local (mostly property tax), $298.6 million state, $53.2 million federal. Long-term debt: $513.7 million.
Spent $395.9 million — $335.6 million to run schools, about $17,188 per student, plus $16.8 million on buildings and equipment. Money in: $173.9 million local (mostly property tax), $251.2 million state, $11.1 million federal. Long-term debt: $700.5 million.
Spent $519 million — $382.8 million to run schools, about $20,051 per student, plus $95.2 million on buildings and equipment. Money in: $244.3 million local (mostly property tax), $247.6 million state, $22.7 million federal. Long-term debt: $743.1 million.
Spent $429 million — $371.7 million to run schools, about $20,594 per student, plus $38.4 million on buildings and equipment. Money in: $125.5 million local (mostly property tax), $260.9 million state, $57.5 million federal. Long-term debt: $364.6 million.
Spent $443.7 million — $332.5 million to run schools, about $18,620 per student, plus $80.3 million on buildings and equipment. Money in: $95.6 million local (mostly property tax), $250.9 million state, $40.4 million federal. Long-term debt: $475.6 million.
And 10 more.
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 High compared with other U.S. counties. FEMA estimates natural hazards cost King County about $1.7 billion 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.
1,252 bridges in King County: 595 in good condition, 607 fair, and 50 poor (4.0%). “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.
| I-5 over LUCILE ST · built 1966 | 96,847 vehicles a day |
| I-90 over MERCER SL · built 1970 | 74,410 vehicles a day |
| I-90 over MERCER SLOUGH · built 1940 | 74,410 vehicles a day |
| I-90 over LAKE WASHINGTON · built 1940 | 68,544 vehicles a day |
| W.B. & REV I-90 over LAKE WASHINGTON · built 1989 | 68,544 vehicles a day |
| S BOEING ACCESS RD over AIRPORT WAY BAR RAMP · built 1952 | 40,000 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $2.4 billion of work in King County in fiscal 2025, about $1,047 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 Washington 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 King 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 King County built: brayden.ozark@gmail.com.
More of Washington: the state government and every county in Washington.
Nearby counties: Pierce County (34 mi) · Snohomish County (39 mi) · Kitsap County (39 mi) · Kittitas County (60 mi) · Thurston County (60 mi) · Island County (60 mi).