US Bridges

7 Mile Lane over Edgar Slough Overflow

Fair

Butte County, California · 0.25 MI N of Nelson RD · Structure no. 12C0075

Built
1935
90 years old, rebuilt 1956
Condition
Fair
inspected August 2023
Type
Slab
Concrete Continuous
Length
34 ft
3 main spans
Daily traffic
184
2018 count
Owner
County
County Highway Agency

About this bridge

7 Mile Lane over Edgar Slough Overflow is a concrete continuous slab carrying 7 Mile Lane over Edgar Slough Overflow in Butte County, California. It was built in 1935 and reconstructed in 1956, so it is 90 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 184 vehicles a day, roughly 13% of them trucks, projected to reach 734 by 2041. The structure is 34 ft (10.4 m) long and 35 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
Carries7 Mile Lane
CrossesEdgar Slough Overflow
Location0.25 MI N of Nelson RD
RouteCounty Highway 0
CountyButte County
StateCalifornia
Coordinates39.54816, -121.9086
Functional classRural Minor 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.9 US tons
Inventory rating25.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length34 ft (10.4 m)
Longest span11 ft (3.4 m)
Deck width35 ft (10.6 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic184 (2018)
Projected traffic734 by 2041
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 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 7 Mile Lane over Edgar Slough Overflow built?

It was built in 1935, making it 90 years old in 2025. It was reconstructed in 1956.

What condition is 7 Mile Lane over Edgar Slough 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 August 2023.

How much traffic does 7 Mile Lane over Edgar Slough Overflow carry?

About 184 vehicles per day (2018 count), of which roughly 13% are trucks.

How long is 7 Mile Lane over Edgar Slough Overflow?

The structure is 34 ft (10.4 m) long with a longest span of 11 ft (3.4 m) and a deck 35 ft wide.

Who owns 7 Mile Lane over Edgar Slough Overflow?

It is owned by the County Highway Agency.