US Bridges

Wapato Road South over Marion Drain

Fair

Yakima County, Washington · 00.01 N Mariondrain · Structure no. 083446000000000

Built
1974
51 years old
Condition
Fair
inspected January 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
72 ft
1 main span
Daily traffic
69
2023 count
Owner
County
County Highway Agency

About this bridge

Wapato Road South over Marion Drain is a prestressed concrete stringer/multi-beam or girder carrying Wapato Road South over Marion Drain in Yakima 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 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 69 vehicles a day, roughly 5% of them trucks, projected to reach 75 by 2043. The structure is 72 ft (21.9 m) long and 32 ft wide. If it were closed, the detour would be 5 mi (8 km).

CarriesWapato Road South
CrossesMarion Drain
Location00.01 N Mariondrain
RouteCounty Highway 50470
Coordinates46.325, -120.41667
Functional classRural Minor Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating19.3 US tons
Inventory rating13.9 US tons

Structure

MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length72 ft (21.9 m)
Longest span70 ft (21.3 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic69 (2023)
Projected traffic75 by 2043
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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$3 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Wapato Road South over Marion Drain built?

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

What condition is Wapato Road South over Marion Drain 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 2023.

How much traffic does Wapato Road South over Marion Drain carry?

About 69 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Wapato Road South over Marion Drain?

The structure is 72 ft (21.9 m) long with a longest span of 70 ft (21.3 m) and a deck 32 ft wide.

Who owns Wapato Road South over Marion Drain?

It is owned by the County Highway Agency.