157,869 people (2024 Census estimate, +2.5% since 2020)
933 square miles of land · 169 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.
63 active community water systems list Merrimack County in the area they serve, reporting 89,539 people served in all (a system that crosses county lines counts its whole population).
| CONCORD WATER DEPT surface water · local government · NH0501010 | 44,215 served |
| FRANKLIN WATER WORKS groundwater · local government · NH0851010 | 7,200 served |
| PEMBROKE WATER WORKS groundwater · local government · NH1861010 | 5,200 served |
| CENTRAL HOOKSETT WATER PCT buys surface water · local government · NH1181010 | 4,650 served |
| PENACOOK BOSCAWEN WATER PCT groundwater · local government · NH0251010 | 3,800 served |
| NEW LONDON SPRINGFIELD WATER groundwater · local government · NH1721010 | 3,250 served |
| COGSWELL SPRINGS WATER WORKS groundwater · local government · NH1121010 | 3,000 served |
| HOOKSETT VILLAGE WATER PCT groundwater · local government · NH1181020 | 3,000 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 193 people were held in Merrimack County's jail, in Vera's latest figure (2024), or 189 per 100,000 residents ages 15–64. In 2019 it was about 171.
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.
22 school districts have their office in Merrimack County. School taxes are usually the largest part of a property tax bill.
Spent $103 million — $98.5 million to run schools, about $24,406 per student, plus $3.1 million on buildings and equipment. Money in: $70 million local (mostly property tax), $26.1 million state, $13.5 million federal. Long-term debt: $43.6 million.
Spent $46.7 million — $43.2 million to run schools, about $19,273 per student, plus $2.8 million on buildings and equipment. Money in: $28.6 million local (mostly property tax), $13.9 million state, $4.4 million federal.
Spent $45.7 million — $43.3 million to run schools, about $24,958 per student, plus $1.4 million on buildings and equipment. Money in: $33.6 million local (mostly property tax), $11 million state, $2.1 million federal. Long-term debt: $4.7 million.
Spent $32.4 million — $31.3 million to run schools, about $18,784 per student, plus $816,000 on buildings and equipment. Money in: $24.9 million local (mostly property tax), $7.2 million state, $1.1 million federal. Long-term debt: $1 million.
Spent $29.3 million — $27.5 million to run schools, about $19,135 per student, plus $1.2 million on buildings and equipment. Money in: $19.7 million local (mostly property tax), $7.7 million state, $2.6 million federal.
Spent $37.2 million — $28.8 million to run schools, about $22,730 per student, plus $82,000 on buildings and equipment. Money in: $28.3 million local (mostly property tax), $9.3 million state, $1.5 million federal. Long-term debt: $1 million.
Spent $22.9 million — $21.7 million to run schools, about $23,087 per student, plus $854,000 on buildings and equipment. Money in: $17.7 million local (mostly property tax), $4.3 million state, $834,000 federal. Long-term debt: $8.5 million.
Spent $21 million — $19.1 million to run schools, about $20,320 per student, plus $1.7 million on buildings and equipment. Money in: $5.6 million local (mostly property tax), $10.3 million state, $4.8 million federal. Long-term debt: $2.5 million.
And 14 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 Merrimack County about $48.8 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Very Low.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
326 bridges in Merrimack County: 146 in good condition, 153 fair, and 27 poor (8.3%). “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.
| I-89 over SOUTH STREET · built 1959 | 46,612 vehicles a day |
| US202 over NHRR CONSTITUTION AV. · built 1958 | 45,555 vehicles a day |
| I-393 US 4 US202 over FORT EDDY RD · built 1980 | 40,527 vehicles a day |
| NH 9(LOUDON ROAD) over MERRIMACK RIVER · built 1966 | 23,721 vehicles a day |
| I-393 US 4 US202 over I-93 · built 1958 | 22,391 vehicles a day |
| I-89 SB over TURKEY POND · built 1959 | 20,703 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $384.9 million of work in Merrimack County in fiscal 2025, about $2,503 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 Hampshire 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 Merrimack 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 Merrimack County built: brayden.ozark@gmail.com.
More of New Hampshire: the state government and every county in New Hampshire.
Nearby counties: Belknap County (20 mi) · Hillsborough County (27 mi) · Sullivan County (28 mi) · Strafford County (32 mi) · Rockingham County (36 mi) · Cheshire County (38 mi).