US Bridges

County Road over Wahluke Branch Canal

Good

Franklin County, Washington · 6.72 N JCT 460 · Structure no. 081939000000000

Built
1974
51 years old
Condition
Good
inspected November 2022
Type
Tee Beam
Prestressed Concrete
Length
100 ft
1 main span
Daily traffic
369
2022 count
Owner
County
County Highway Agency

About this bridge

County Road over Wahluke Branch Canal is a prestressed concrete tee beam carrying County Road over Wahluke Branch Canal in Franklin County, Washington. It was built in 1974, so it is 51 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 369 vehicles a day, roughly 40% of them trucks, projected to reach 548 by 2042. The structure is 100 ft (30.5 m) long and 30 ft wide. If it were closed, the detour would be 18 mi (29 km).

Location

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CarriesCounty Road
CrossesWahluke Branch Canal
Location6.72 N JCT 460
RouteCounty Highway 4450
CountyFranklin County
StateWashington
Coordinates46.70031, -119.30169
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2022
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
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating24.7 US tons
Inventory rating19 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length100 ft (30.5 m)
Longest span100 ft (30.5 m)
Deck width30 ft (9.1 m)
Roadway width29 ft (8.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic369 (2022)
Projected traffic548 by 2042
Trucks40%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County Road over Wahluke Branch Canal built?

It was built in 1974, making it 51 years old in 2025.

What condition is County Road over Wahluke Branch Canal in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2022.

How much traffic does County Road over Wahluke Branch Canal carry?

About 369 vehicles per day (2022 count), of which roughly 40% are trucks.

How long is County Road over Wahluke Branch Canal?

The structure is 100 ft (30.5 m) long with a longest span of 100 ft (30.5 m) and a deck 30 ft wide.

Who owns County Road over Wahluke Branch Canal?

It is owned by the County Highway Agency.