112,031 people (2024 Census estimate, +2.3% since 2020)
357 square miles of land · 314 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.
24 active community water systems list Warren County in the area they serve, reporting 290,497 people served in all (a system that crosses county lines counts its whole population).
| NJ AMERICAN WATER - SHORT HILLS surface water · private · NJ0712001 | 217,230 served |
| AQUA NJ - PHILLIPSBURG groundwater (surface-influenced) · private · NJ2119001 | 26,686 served |
| HACKETTSTOWN MUA groundwater · local government · NJ2108001 | 22,000 served |
| NJ AMERICAN WATER - WASHINGTON/OXFORD groundwater · private · NJ2121001 | 10,719 served |
| ALLAMUCHY TWP WATER & SEWER groundwater · local government · NJ2101001 | 5,423 served |
| NJ AMERICAN WATER - BELVIDERE groundwater · private · NJ2103001 | 2,854 served |
| ALPHA MUNICIPAL WATER WORKS groundwater · local government · NJ2102001 | 2,530 served |
| TOWNSHIP OF BLAIRSTOWN DPW groundwater · local government · NJ2104001 | 800 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 99 people were held in Warren County's jail, in Vera's latest figure (2020), or 137 per 100,000 residents ages 15–64. In 2015 it was about 126.
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.
23 school districts have their office in Warren County. School taxes are usually the largest part of a property tax bill.
Spent $111.5 million — $105.8 million to run schools, about $26,529 per student, plus $3.6 million on buildings and equipment. Money in: $32.8 million local (mostly property tax), $67.5 million state, $15 million federal. Long-term debt: $6.2 million.
Spent $52.8 million — $49.3 million to run schools, about $23,715 per student, plus $3.4 million on buildings and equipment. Money in: $26.9 million local (mostly property tax), $21.4 million state, $2.2 million federal. Long-term debt: $4.1 million.
Spent $46.8 million — $43.1 million to run schools, about $27,121 per student, plus $917,000 on buildings and equipment. Money in: $29.2 million local (mostly property tax), $19.4 million state, $2.1 million federal. Long-term debt: $9.3 million.
Spent $22.3 million — $14.9 million to run schools, about $20,229 per student, plus $1.2 million on buildings and equipment. Money in: $16.1 million local (mostly property tax), $6.7 million state, $645,000 federal. Long-term debt: $8.9 million.
Spent $21.3 million — $15.2 million to run schools, about $23,033 per student. Money in: $12.3 million local (mostly property tax), $8.4 million state, $897,000 federal. Long-term debt: $435,000.
Spent $21.5 million — $14.9 million to run schools, about $23,125 per student, plus $290,000 on buildings and equipment. Money in: $16.4 million local (mostly property tax), $5.6 million state, $1.4 million federal. Long-term debt: $1.5 million.
Spent $18.9 million — $18 million to run schools, about $28,732 per student, plus $365,000 on buildings and equipment. Money in: $13.8 million local (mostly property tax), $5.7 million state, $926,000 federal.
Spent $18.2 million — $18 million to run schools, about $29,859 per student, plus $156,000 on buildings and equipment. Money in: $9.9 million local (mostly property tax), $7.5 million state, $661,000 federal.
And 15 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 Low compared with other U.S. counties. FEMA estimates natural hazards cost Warren County about $57.3 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.
268 bridges in Warren County: 50 in good condition, 206 fair, and 12 poor (4.5%). “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.
| NJ 31 over FURNACE BROOK · built 1926 | 12,730 vehicles a day |
| NJ 57 over MILL BROOK · built 1922 | 11,809 vehicles a day |
| NJ 57 over LOPATCONG CREEK TRIBUTAR · built 1921 | 10,951 vehicles a day |
| NJ 57 over LOPATCONG CREEK · built 1921 | 10,356 vehicles a day |
| US 46 over PAULINS KILL · built 1933 | 9,721 vehicles a day |
| South Main Street over Washington Scndry (N&S) · built 1910 | 9,013 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $61.7 million of work in Warren County in fiscal 2025, about $563 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 New Jersey 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 Warren 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 Warren County built: brayden.ozark@gmail.com.
More of New Jersey: the state government and every county in New Jersey.
Nearby counties: Northampton County, PA (17 mi) · Hunterdon County (21 mi) · Monroe County, PA (22 mi) · Morris County (24 mi) · Sussex County (26 mi) · Somerset County (28 mi).