US Bridges

Harkins Slough RD over Watsonville Slough

Fair

Santa Cruz County, California · West of Ohlone Parkway · Structure no. 36C0166

Built
2008
17 years old
Condition
Fair
inspected November 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
751 ft
8 main spans
Daily traffic
5,000
2016 count
Owner
City
City or Municipal Highway Agency

About this bridge

Harkins Slough RD over Watsonville Slough is a prestressed concrete continuous box beam or girders - multiple carrying Harkins Slough RD over Watsonville Slough in Santa Cruz County, California. It was built in 2008, so it is 17 years old, younger 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 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 5,000 vehicles a day, roughly 5% of them trucks, projected to reach 11,222 by 2046. The structure is 751 ft (229 m) long and 86 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesHarkins Slough RD
CrossesWatsonville Slough
LocationWest of Ohlone Parkway
RouteCity Street 0
Coordinates36.91499, -121.78143
Functional classRural 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans8
Design loadHS 20 + Mod
Structure length751 ft (229 m)
Longest span100 ft (30.5 m)
Deck width86 ft (26.2 m)
Roadway width72 ft (21.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,000 (2016)
Projected traffic11,222 by 2046
Trucks5%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 Harkins Slough RD over Watsonville Slough built?

It was built in 2008, making it 17 years old in 2025.

What condition is Harkins Slough RD over Watsonville Slough 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 November 2024.

How much traffic does Harkins Slough RD over Watsonville Slough carry?

About 5,000 vehicles per day (2016 count), of which roughly 5% are trucks.

How long is Harkins Slough RD over Watsonville Slough?

The structure is 751 ft (229 m) long with a longest span of 100 ft (30.5 m) and a deck 86 ft wide.

Who owns Harkins Slough RD over Watsonville Slough?

It is owned by the City or Municipal Highway Agency.