281,843 people (2024 Census estimate, −0.0% since 2020)
3,301 square miles of land · 85 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.
72 active community water systems list San Luis Obispo County in the area they serve, reporting 266,435 people served in all (a system that crosses county lines counts its whole population).
| SAN LUIS OBISPO WATER DEPARTMENT surface water · local government · CA4010009 | 49,534 served |
| ATASCADERO MUTUAL WATER CO groundwater · private · CA4010002 | 33,307 served |
| CITY OF PASO ROBLES WATER DIVISION surface water · local government · CA4010007 | 31,176 served |
| CITY OF ARROYO GRANDE UTILITIES DIVISION buys surface water · local government · CA4010001 | 17,963 served |
| CALIFORNIA MENS COLONY surface water · state · CA4010830 | 15,000 served |
| NIPOMO COMM SERVICES DIST buys surface water · local government · CA4010026 | 13,771 served |
| CITY OF GROVER BEACH PUBLIC WORKS DEPT surface water · local government · CA4010004 | 12,701 served |
| MORRO BAY PW DEPT - WATER DIVISION buys surface water · local government · CA4010011 | 10,757 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 484 people were held in San Luis Obispo County's jail, in Vera's latest figure (2025). In 2020 it was about 428.
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.
11 school districts have their office in San Luis Obispo County. School taxes are usually the largest part of a property tax bill.
Spent $189.1 million — $152.1 million to run schools, about $15,856 per student, plus $28.8 million on buildings and equipment. Money in: $104.7 million local (mostly property tax), $85.5 million state, $14.3 million federal. Long-term debt: $130.8 million.
Spent $175.7 million — $136.9 million to run schools, about $18,117 per student, plus $30.7 million on buildings and equipment. Money in: $113.3 million local (mostly property tax), $32.7 million state, $10.9 million federal. Long-term debt: $158.6 million.
Spent $119.7 million — $103.4 million to run schools, about $16,310 per student, plus $9.8 million on buildings and equipment. Money in: $63.4 million local (mostly property tax), $52.3 million state, $11.4 million federal. Long-term debt: $91.1 million.
Spent $75.7 million — $64.2 million to run schools, about $14,952 per student, plus $6.9 million on buildings and equipment. Money in: $50.4 million local (mostly property tax), $37.8 million state, $6.5 million federal. Long-term debt: $101.3 million.
Spent $36.2 million — $32.5 million to run schools, about $14,378 per student, plus $2 million on buildings and equipment. Money in: $19.7 million local (mostly property tax), $28.3 million state, $1.8 million federal. Long-term debt: $33.4 million.
Spent $15.1 million — $10.1 million to run schools, about $15,478 per student, plus $3.7 million on buildings and equipment. Money in: $5.9 million local (mostly property tax), $7.6 million state, $1.7 million federal. Long-term debt: $7.4 million.
Spent $17.7 million — $14.9 million to run schools, about $30,611 per student, plus $1.1 million on buildings and equipment. Money in: $15.4 million local (mostly property tax), $3.4 million state, $1.7 million federal. Long-term debt: $6.7 million.
Spent $69.3 million — $34.2 million to run schools, about $110,319 per student, plus $1.2 million on buildings and equipment. Money in: $43.8 million local (mostly property tax), $30 million state, $16.7 million federal.
And 3 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 San Luis Obispo County about $213.9 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
402 bridges in San Luis Obispo County: 210 in good condition, 170 fair, and 22 poor (5.5%). “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.
| NIBLICK ROAD over US HIGHWAY 101 · built 1987 | 30,055 vehicles a day |
| US HIGHWAY 101 SB over ATASCADERO CREEK · built 1956 | 30,000 vehicles a day |
| US HIGHWAY 101 NB over ATASCADERO CREEK · built 1956 | 30,000 vehicles a day |
| US HIGHWAY 101 SB over TRAFFIC WAY · built 1956 | 30,000 vehicles a day |
| US HIGHWAY 101 NB over TRAFFIC WAY · built 1956 | 30,000 vehicles a day |
| US HIGHWAY 101 SB over SANTA MARGARITA CREEK · built 1956 | 21,000 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $212 million of work in San Luis Obispo County in fiscal 2025, about $751 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; drop boxes open: 2026-10-05. Last day to register to vote: 2026-10-19. Early in-person voting: 2026-10-24 to 2026-11-03. Election Day: 2026-11-03. Last day for mailed ballots to arrive: 2026-11-10.
Source: California Secretary of State — Nov. 3, 2026 key dates · California Official Voter Information Guide — dates to remember · California Secretary of State — make a plan to vote
The budget, property tax rates, audits, local officials and offices for San Luis Obispo 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 San Luis Obispo County built: brayden.ozark@gmail.com.
More of California: the state government and every county in California.
Nearby counties: Kings County (59 mi) · Santa Barbara County (63 mi) · Monterey County (76 mi) · San Benito County (92 mi) · Kern County (97 mi) · Ventura County (103 mi).