US Bridges

Powerhouse RD 248A over Williams Creek

Good

Mendocino County, California · 0.3 MI South Gibson Lane · Structure no. 10C0224

Built
2020
5 years old
Condition
Good
inspected August 2021
Type
Slab
Prestressed Concrete
Length
50 ft
1 main span
Daily traffic
134
2011 count
Owner
County
County Highway Agency

About this bridge

Powerhouse RD 248A over Williams Creek is a prestressed concrete slab carrying Powerhouse RD 248A over Williams Creek in Mendocino County, California. It was built in 2020, so it is 5 years old, younger than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 134 vehicles a day, roughly 2% of them trucks, projected to reach 123 by 2041. The structure is 50 ft (15.2 m) long and 31 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesPowerhouse RD 248A
CrossesWilliams Creek
Location0.3 MI South Gibson Lane
RouteCounty Highway 0
Coordinates39.33161, -123.11772
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: 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 rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length50 ft (15.2 m)
Longest span46 ft (13.9 m)
Deck width31 ft (9.6 m)
Roadway width27 ft (8.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic134 (2011)
Projected traffic123 by 2041
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 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 Powerhouse RD 248A over Williams Creek built?

It was built in 2020, making it 5 years old in 2025.

What condition is Powerhouse RD 248A over Williams Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2021.

How much traffic does Powerhouse RD 248A over Williams Creek carry?

About 134 vehicles per day (2011 count), of which roughly 2% are trucks.

How long is Powerhouse RD 248A over Williams Creek?

The structure is 50 ft (15.2 m) long with a longest span of 46 ft (13.9 m) and a deck 31 ft wide.

Who owns Powerhouse RD 248A over Williams Creek?

It is owned by the County Highway Agency.