427,253 people (2024 Census estimate, −2.8% since 2020)
301 square miles of land · 1,420 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.
4 active community water systems list Jefferson Parish in the area they serve, reporting 440,987 people served in all (a system that crosses county lines counts its whole population).
| E JEFFERSON WW DISTRICT 1 surface water · local government · LA1051001 | 275,163 served |
| W JEFFERSON WW DISTRICT 2 surface water · local government · LA1051004 | 140,264 served |
| GRETNA WATERWORKS surface water · local government · LA1051003 | 17,026 served |
| WESTWEGO WATERWORKS buys surface water · local government · LA1051005 | 8,534 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 1,086 people were held in Jefferson Parish's jail, in Vera's latest figure (2021), or 396 per 100,000 residents ages 15–64. In 2016 it was about 937.
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.
1 school district has its office in Jefferson Parish. School taxes are usually the largest part of a property tax bill.
Spent $805.4 million — $716.7 million to run schools, about $14,155 per student, plus $59 million on buildings and equipment. Money in: $462.6 million local (mostly property tax), $257.4 million state, $180.1 million federal. Long-term debt: $263.4 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 High compared with other U.S. counties. FEMA estimates natural hazards cost Jefferson Parish about $370.9 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively High.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
381 bridges in Jefferson Parish: 226 in good condition, 139 fair, and 16 poor (4.2%). “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.
| I0010 over VET MEM HWY · built 1967 | 137,542 vehicles a day |
| LA3046 over R/R CITY STREETS LA 611 · built 1957 | 55,994 vehicles a day |
| I0010 over VET MEM HWY · built 1967 | 41,695 vehicles a day |
| W. METAIRIE AVE over SUBURBAN CANAL · built 1968 | 24,900 vehicles a day |
| WALL BLVD over BAYOU FATMA · built 1980 | 8,000 vehicles a day |
| LA3046 over LA SOU/KCS RR & CLAIBORN · built 1957 | 7,806 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $217.9 million of work in Jefferson Parish in fiscal 2025, about $494 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 Louisiana 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 Jefferson Parish 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 Jefferson Parish built: brayden.ozark@gmail.com.
More of Louisiana: the state government and every county in Louisiana.
Nearby counties: Lafourche Parish (22 mi) · Plaquemines Parish (32 mi) · St. Charles Parish (34 mi) · Orleans Parish (38 mi) · Terrebonne Parish (50 mi) · St. John the Baptist Parish (52 mi).