US Bridges

Nelson RD over Edgar Slough Overflow

Fair

Butte County, California · 0.2 MI E of 7 MI Lane · Structure no. 12C0403

Built
1927
98 years old
Condition
Fair
inspected January 2025
Type
Tee Beam
Concrete Continuous
Length
70 ft
3 main spans
Daily traffic
50
2019 count
Owner
County
County Highway Agency

About this bridge

Nelson RD over Edgar Slough Overflow is a concrete continuous tee beam carrying Nelson RD over Edgar Slough Overflow in Butte County, California. It was built in 1927, so it is 98 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 50 vehicles a day, projected to reach 81 by 2044. The structure is 70 ft (21.3 m) long and 23 ft wide. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
CarriesNelson RD
CrossesEdgar Slough Overflow
Location0.2 MI E of 7 MI Lane
RouteCounty Highway 0
CountyButte County
StateCalifornia
Coordinates39.54584, -121.90489
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2025
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27.9 US tons
Inventory rating21.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length70 ft (21.3 m)
Longest span23 ft (7 m)
Deck width23 ft (7 m)
Roadway width21 ft (6.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2019)
Projected traffic81 by 2044
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 Nelson RD over Edgar Slough Overflow built?

It was built in 1927, making it 98 years old in 2025.

What condition is Nelson RD 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 January 2025.

How much traffic does Nelson RD over Edgar Slough Overflow carry?

About 50 vehicles per day (2019 count).

How long is Nelson RD over Edgar Slough Overflow?

The structure is 70 ft (21.3 m) long with a longest span of 23 ft (7 m) and a deck 23 ft wide.

Who owns Nelson RD over Edgar Slough Overflow?

It is owned by the County Highway Agency.