US Bridges

S NW over Irrigation Canal

Good

Grant County, Washington · S NW .4 S of SR 28 · Structure no. 087146000000000

Built
2004
21 years old
Condition
Good
inspected December 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
38 ft
1 main span
Daily traffic
663
2020 count
Owner
County
County Highway Agency

About this bridge

S NW over Irrigation Canal is a prestressed concrete stringer/multi-beam or girder carrying S NW over Irrigation Canal in Grant County, Washington. It was built in 2004, so it is 21 years old, younger 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 663 vehicles a day, roughly 23% of them trucks, projected to reach 1,000 by 2042. The structure is 38 ft (11.6 m) long and 30 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesS NW
CrossesIrrigation Canal
LocationS NW .4 S of SR 28
RouteCounty Highway 31550
CountyGrant County
StateWashington
Coordinates47.22638, -119.89671
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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.8 US tons
Inventory rating43.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 25 or greater
Structure length38 ft (11.6 m)
Longest span37 ft (11.3 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic663 (2020)
Projected traffic1,000 by 2042
Trucks23%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedDeck rehabilitation with only incidental widening
Estimated improvement cost$578,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was S NW over Irrigation Canal built?

It was built in 2004, making it 21 years old in 2025.

What condition is S NW over Irrigation 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 December 2023.

How much traffic does S NW over Irrigation Canal carry?

About 663 vehicles per day (2020 count), of which roughly 23% are trucks.

How long is S NW over Irrigation Canal?

The structure is 38 ft (11.6 m) long with a longest span of 37 ft (11.3 m) and a deck 30 ft wide.

Who owns S NW over Irrigation Canal?

It is owned by the County Highway Agency.