US Bridges

NH104 over Bog Pond Brook

Fair

Merrimack County, New Hampshire · 2.4 MI SW Hill Tl · Structure no. 005801520012800

Built
1930
95 years old
Condition
Fair
inspected May 2024
Type
Culvert
Concrete
Length
20 ft
1 main span
Daily traffic
2,913
2023 count
Owner
State
State Highway Agency

About this bridge

NH104 over Bog Pond Brook is a concrete culvert carrying NH104 over Bog Pond Brook in Merrimack County, New Hampshire. It was built in 1930, so it is 95 years old, older than the New Hampshire average of 56.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 2,913 vehicles a day, roughly 7% of them trucks, projected to reach 4,311 by 2043. The structure is 20 ft (6.1 m) long and 46 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesNH104
CrossesBog Pond Brook
Location2.4 MI SW Hill Tl
RouteState Highway 104
CountyMerrimack County
StateNew Hampshire
Coordinates43.52024, -71.83816
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61 US tons
Inventory rating37 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadH 15
Structure length20 ft (6.1 m)
Longest span20 ft (6.1 m)
Deck width46 ft (14 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,913 (2023)
Projected traffic4,311 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$314,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was NH104 over Bog Pond Brook built?

It was built in 1930, making it 95 years old in 2025.

What condition is NH104 over Bog Pond Brook in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in May 2024.

How much traffic does NH104 over Bog Pond Brook carry?

About 2,913 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is NH104 over Bog Pond Brook?

The structure is 20 ft (6.1 m) long with a longest span of 20 ft (6.1 m) and a deck 46 ft wide.

Who owns NH104 over Bog Pond Brook?

It is owned by the State Highway Agency.