US Bridges

Warm Springs RD over Calabazas Creek

Fair

Sonoma County, California · Near Arnold DR · Structure no. 20C0215

Built
1928
97 years old, rebuilt 1975
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
44 ft
2 main spans
Daily traffic
3,000
2015 count
Owner
County
County Highway Agency

About this bridge

Warm Springs RD over Calabazas Creek is a steel stringer/multi-beam or girder carrying Warm Springs RD over Calabazas Creek in Sonoma County, California. It was built in 1928 and reconstructed in 1975, so it is 97 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 3,000 vehicles a day, roughly 2% of them trucks, projected to reach 5,897 by 2040. The structure is 44 ft (13.4 m) long and 27 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesWarm Springs RD
CrossesCalabazas Creek
LocationNear Arnold DR
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.36437, -122.52541
Functional classUrban 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.1 US tons
Inventory rating18.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length44 ft (13.4 m)
Longest span21 ft (6.4 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2015)
Projected traffic5,897 by 2040
Trucks2%
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

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Warm Springs RD over Calabazas Creek built?

It was built in 1928, making it 97 years old in 2025. It was reconstructed in 1975.

What condition is Warm Springs RD over Calabazas 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 May 2023.

How much traffic does Warm Springs RD over Calabazas Creek carry?

About 3,000 vehicles per day (2015 count), of which roughly 2% are trucks.

How long is Warm Springs RD over Calabazas Creek?

The structure is 44 ft (13.4 m) long with a longest span of 21 ft (6.4 m) and a deck 27 ft wide.

Who owns Warm Springs RD over Calabazas Creek?

It is owned by the County Highway Agency.