US Bridges

Calistoga RD over Weeks Creek

Fair

Sonoma County, California · At St. Helena RD · Structure no. 20C0123

Built
1953
72 years old
Condition
Fair
inspected October 2024
Type
Culvert
Concrete Continuous
Length
25 ft
2 main spans
Daily traffic
6,000
2015 count
Owner
County
County Highway Agency

About this bridge

Calistoga RD over Weeks Creek is a concrete continuous culvert carrying Calistoga RD over Weeks Creek in Sonoma County, California. It was built in 1953, so it is 72 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 6,000 vehicles a day, roughly 1% of them trucks, projected to reach 4,391 by 2046. The structure is 25 ft (7.6 m) long. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesCalistoga RD
CrossesWeeks Creek
LocationAt St. Helena RD
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.5057, -122.64994
Functional classRural Major 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
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadUnknown
Structure length25 ft (7.6 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,000 (2015)
Projected traffic4,391 by 2046
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Calistoga RD over Weeks Creek built?

It was built in 1953, making it 72 years old in 2025.

What condition is Calistoga RD over Weeks Creek 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 October 2024.

How much traffic does Calistoga RD over Weeks Creek carry?

About 6,000 vehicles per day (2015 count), of which roughly 1% are trucks.

How long is Calistoga RD over Weeks Creek?

The structure is 25 ft (7.6 m) long with a longest span of 12 ft (3.7 m).

Who owns Calistoga RD over Weeks Creek?

It is owned by the County Highway Agency.