US Bridges

M RD NW over Irrigation Lateral

Fair

Grant County, Washington · M NW .6 N of 12 · Structure no. 084853000000000

Built
1952
73 years old
Condition
Fair
inspected January 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
32 ft
1 main span
Daily traffic
247
2021 count
Owner
County
County Highway Agency

About this bridge

M RD NW over Irrigation Lateral is a wood or timber stringer/multi-beam or girder carrying M RD NW over Irrigation Lateral in Grant County, Washington. It was built in 1952, so it is 73 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.

It carries about 247 vehicles a day, roughly 21% of them trucks, projected to reach 450 by 2042. The structure is 32 ft (9.8 m) long and 25 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesM RD NW
CrossesIrrigation Lateral
LocationM NW .6 N of 12
RouteCounty Highway 32470
CountyGrant County
StateWashington
Coordinates47.27, -119.76895
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 inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to 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 rating37 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 length32 ft (9.8 m)
Longest span31 ft (9.4 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic247 (2021)
Projected traffic450 by 2042
Trucks21%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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$1.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was M RD NW over Irrigation Lateral built?

It was built in 1952, making it 73 years old in 2025.

What condition is M 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 January 2024.

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

About 247 vehicles per day (2021 count), of which roughly 21% are trucks.

How long is M RD NW over Irrigation Lateral?

The structure is 32 ft (9.8 m) long with a longest span of 31 ft (9.4 m) and a deck 25 ft wide.

Who owns M RD NW over Irrigation Lateral?

It is owned by the County Highway Agency.