US Bridges

Birchwood Ave. over Bug Lake Overflow

Fair

Whatcom County, Washington · JCT Birchwood/Squalicum · Structure no. 085824000000000

Built
1987
38 years old
Condition
Fair
inspected May 2023
Type
Culvert
Steel
Length
24 ft
3 main spans
Daily traffic
6,200
2021 count
Owner
City
City or Municipal Highway Agency

About this bridge

Birchwood Ave. over Bug Lake Overflow is a steel culvert carrying Birchwood Ave. over Bug Lake Overflow in Whatcom County, Washington. It was built in 1987, so it is 38 years old, younger 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 6,200 vehicles a day, roughly 5% of them trucks, projected to reach 8,800 by 2043. The structure is 24 ft (7.3 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesBirchwood Ave.
CrossesBug Lake Overflow
LocationJCT Birchwood/Squalicum
RouteCity Street 86802
CountyWhatcom County
StateWashington
Coordinates48.77694, -122.47537
Functional classUrban 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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating48.6 US tons
Inventory rating28.9 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans3
Design loadUnknown
Structure length24 ft (7.3 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,200 (2021)
Projected traffic8,800 by 2043
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Birchwood Ave. over Bug Lake Overflow built?

It was built in 1987, making it 38 years old in 2025.

What condition is Birchwood Ave. over Bug Lake Overflow 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 May 2023.

How much traffic does Birchwood Ave. over Bug Lake Overflow carry?

About 6,200 vehicles per day (2021 count), of which roughly 5% are trucks.

How long is Birchwood Ave. over Bug Lake Overflow?

The structure is 24 ft (7.3 m) long with a longest span of 10 ft (3 m).

Who owns Birchwood Ave. over Bug Lake Overflow?

It is owned by the City or Municipal Highway Agency.