US Bridges

1 RD NW over Irrigation Lateral

FairPosted for load

Grant County, Washington · 1 NW .5 W of U · Structure no. 084546000000000

Built
1956
69 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
28 ft
1 main span
Daily traffic
231
2022 count
Owner
County
County Highway Agency

About this bridge

1 RD NW over Irrigation Lateral is a wood or timber stringer/multi-beam or girder carrying 1 RD NW over Irrigation Lateral in Grant County, Washington. It was built in 1956, so it is 69 years old, older than the Washington average of 49.8 years.

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

It carries about 231 vehicles a day, roughly 22% of them trucks, projected to reach 300 by 2042. The structure is 28 ft (8.5 m) long and 25 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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Carries1 RD NW
CrossesIrrigation Lateral
Location1 NW .5 W of U
RouteCounty Highway 30990
CountyGrant County
StateWashington
Coordinates47.10198, -119.95009
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38 US tons
Inventory rating26 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadH 15
Structure length28 ft (8.5 m)
Longest span27 ft (8.2 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic231 (2022)
Projected traffic300 by 2042
Trucks22%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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$1.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 1 RD NW over Irrigation Lateral built?

It was built in 1956, making it 69 years old in 2025.

What condition is 1 RD NW over Irrigation Lateral 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 February 2023.

How much traffic does 1 RD NW over Irrigation Lateral carry?

About 231 vehicles per day (2022 count), of which roughly 22% are trucks.

How long is 1 RD NW over Irrigation Lateral?

The structure is 28 ft (8.5 m) long with a longest span of 27 ft (8.2 m) and a deck 25 ft wide.

Who owns 1 RD NW over Irrigation Lateral?

It is owned by the County Highway Agency.