96,509 people (2024 Census estimate, +6.8% since 2020)
1,922 square miles of land · 50 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.
14 active community water systems list Twin Falls County in the area they serve, reporting 71,444 people served in all (a system that crosses county lines counts its whole population).
| TWIN FALLS CITY OF groundwater · local government · ID5420058 | 56,121 served |
| KIMBERLY CITY OF groundwater · local government · ID5420033 | 5,359 served |
| BUHL CITY OF groundwater · local government · ID5420007 | 4,518 served |
| FILER WATER WORKS groundwater · local government · ID5420021 | 2,858 served |
| HANSEN CITY OF groundwater · local government · ID5420027 | 1,200 served |
| CASTLEFORD CITY OF groundwater · local government · ID5420010 | 275 served |
| KANAKA RAPIDS RANCH WATER SYSTEM INC groundwater · private · ID5420089 | 240 served |
| HOLLISTER CITY OF groundwater · local government · ID5420030 | 220 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 297 people were held in Twin Falls County's jail, in Vera's latest figure (2019), or 544 per 100,000 residents ages 15–64. In 2014 it was about 169.
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.
7 school districts have their office in Twin Falls County. School taxes are usually the largest part of a property tax bill.
Spent $95.6 million — $90.3 million to run schools, about $9,657 per student, plus $3.1 million on buildings and equipment. Money in: $21.8 million local (mostly property tax), $65.9 million state, $17.7 million federal. Long-term debt: $73 million.
Spent $19.3 million — $18 million to run schools, about $8,359 per student, plus $558,000 on buildings and equipment. Money in: $4.4 million local (mostly property tax), $14.1 million state, $2.4 million federal. Long-term debt: $21 million.
Spent $15.7 million — $14.1 million to run schools, about $8,835 per student, plus $975,000 on buildings and equipment. Money in: $2.9 million local (mostly property tax), $12 million state, $2.6 million federal. Long-term debt: $6.3 million.
Spent $14.6 million — $13.7 million to run schools, about $10,800 per student, plus $282,000 on buildings and equipment. Money in: $1.6 million local (mostly property tax), $9.6 million state, $3.7 million federal. Long-term debt: $828,000.
Spent $5.5 million — $4.6 million to run schools, about $11,504 per student, plus $700,000 on buildings and equipment. Money in: $1.6 million local (mostly property tax), $3.9 million state, $1.2 million federal. Long-term debt: $5.7 million.
Spent $4.4 million — $4.4 million to run schools, about $13,018 per student, plus $47,000 on buildings and equipment. Money in: $841,000 local (mostly property tax), $3.1 million state, $802,000 federal. Long-term debt: $41,000.
Spent $4.3 million — $3.9 million to run schools, about $12,817 per student, plus $367,000 on buildings and equipment. Money in: $542,000 local (mostly property tax), $3.1 million state, $873,000 federal. Long-term debt: $160,000.
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 Twin Falls County about $16.6 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Relatively Moderate; social vulnerability: Relatively Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
126 bridges in Twin Falls County: 14 in good condition, 107 fair, and 5 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.
| STC7232;BLUE LAKES over ROCK CREEK · built 1959 | 11,500 vehicles a day |
| STC2714;3700 NORTH over ROCK CREEK · built 1973 | 6,000 vehicles a day |
| US 30 over DRY CREEK · built 1934 | 2,900 vehicles a day |
| US 30 over UPRR;BICKEL OVERPASS · built 1936 | 2,500 vehicles a day |
| SHOESTRING ROAD over SNAKE RIVER;SW BLISS BR · built 1977 | 190 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $32.2 million of work in Twin Falls County in fiscal 2025, about $358 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 Idaho 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 Twin Falls 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 Twin Falls County built: brayden.ozark@gmail.com.
More of Idaho: the state government and every county in Idaho.
Nearby counties: Jerome County (31 mi) · Gooding County (44 mi) · Lincoln County (51 mi) · Cassia County (53 mi) · Minidoka County (63 mi) · Owyhee County (79 mi).