718,604 people (2024 Census estimate, +0.7% since 2020)
444 square miles of land · 1,620 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.
103 active community water systems list Lake County in the area they serve, reporting 629,529 people served in all (a system that crosses county lines counts its whole population).
| WAUKEGAN surface water · local government · IL0971900 | 87,149 served |
| VERNON HILLS - LAKE CO PW buys surface water · local government · IL0971750 | 33,207 served |
| MUNDELEIN buys surface water · local government · IL0971150 | 31,500 served |
| GURNEE buys surface water · local government · IL0970350 | 30,193 served |
| HIGHLAND PARK surface water · local government · IL0970500 | 30,176 served |
| ROUND LAKE BEACH buys surface water · local government · IL0971550 | 27,200 served |
| ZION buys surface water · local government · IL0972000 | 24,442 served |
| GREAT LAKES NAVAL TRAINING STATION surface water · federal · IL0975227 | 23,000 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 508 people were held in Lake County's jail, in Vera's latest figure (2024), or 110 per 100,000 residents ages 15–64. In 2019 it was about 632.
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.
44 school districts have their office in Lake County. School taxes are usually the largest part of a property tax bill.
Spent $323.9 million — $298.8 million to run schools, about $21,843 per student, plus $20.9 million on buildings and equipment. Money in: $59 million local (mostly property tax), $245.6 million state, $52.9 million federal. Long-term debt: $28.1 million.
Spent $157 million — $143.4 million to run schools, about $22,655 per student, plus $7.4 million on buildings and equipment. Money in: $36.3 million local (mostly property tax), $115 million state, $18.2 million federal. Long-term debt: $46 million.
Spent $137 million — $115.3 million to run schools, about $20,496 per student, plus $18.4 million on buildings and equipment. Money in: $99.3 million local (mostly property tax), $34.5 million state, $3.7 million federal. Long-term debt: $74.9 million.
Spent $113.3 million — $100.3 million to run schools, about $21,357 per student, plus $8.8 million on buildings and equipment. Money in: $79.5 million local (mostly property tax), $33.8 million state, $5.5 million federal. Long-term debt: $94.3 million.
Spent $176.5 million — $139.9 million to run schools, about $31,167 per student, plus $19 million on buildings and equipment. Money in: $124.7 million local (mostly property tax), $34.1 million state, $3.7 million federal. Long-term debt: $47.9 million.
Spent $93.5 million — $84.7 million to run schools, about $19,309 per student, plus $2.1 million on buildings and equipment. Money in: $64.5 million local (mostly property tax), $39.4 million state, $4.3 million federal. Long-term debt: $28.9 million.
Spent $124.3 million — $95.3 million to run schools, about $25,171 per student, plus $25.1 million on buildings and equipment. Money in: $81.7 million local (mostly property tax), $27.2 million state, $3.8 million federal. Long-term debt: $46.3 million.
Spent $85.8 million — $71.7 million to run schools, about $19,080 per student, plus $7.3 million on buildings and equipment. Money in: $68.6 million local (mostly property tax), $29.5 million state, $3.6 million federal. Long-term debt: $80.7 million.
And 36 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: Relatively High compared with other U.S. counties. FEMA estimates natural hazards cost Lake County about $266.5 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively High; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
250 bridges in Lake County: 76 in good condition, 150 fair, and 24 poor (9.6%). “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 14 over FLINT CREEK TRIB · built 1937 | 24,300 vehicles a day |
| WASHINGTON ST over RR - UP · built 1961 | 16,400 vehicles a day |
| GREEN BAY RD. over U.P.R.R. · built 1988 | 8,500 vehicles a day |
| DILLEYS ROAD over MILL CREEK · built 2002 | 5,600 vehicles a day |
| SHERIDAN RD over IL 176 (SCRANTON RD) · built 1923 | 4,300 vehicles a day |
| FAU-1239 Rockland over DesPlaines River · built 1990 | 3,450 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $107.3 million of work in Lake County in fiscal 2025, about $150 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 Illinois 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 Lake 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 Lake County built: brayden.ozark@gmail.com.
More of Illinois: the state government and every county in Illinois.
Nearby counties: Cook County (22 mi) · DuPage County (27 mi) · Kenosha County, WI (28 mi) · McHenry County (34 mi) · Kane County (36 mi) · Racine County, WI (41 mi).