US Bridges

Jefferson Island over Deblanc Coulee

Fair

Iberia Parish, Louisiana · 1.5 Mi. W. of US 90 · Structure no. 032329593915581

Built
1960
65 years old
Condition
Fair
inspected October 2024
Type
Slab
Concrete
Length
100 ft
5 main spans
Daily traffic
2,868
2020 count
Owner
County
County Highway Agency

About this bridge

Jefferson Island over Deblanc Coulee is a concrete slab carrying Jefferson Island over Deblanc Coulee in Iberia Parish, Louisiana. It was built in 1960, so it is 65 years old, older than the Louisiana average of 43 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 2,868 vehicles a day, roughly 8% of them trucks, projected to reach 3,154 by 2040. The structure is 100 ft (30.5 m) long and 29 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesJefferson Island
CrossesDeblanc Coulee
Location1.5 Mi. W. of US 90
RouteCounty Highway 0
CountyIberia Parish
StateLouisiana
Coordinates29.99762, -91.90734
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating32.8 US tons
Inventory rating25.4 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length100 ft (30.5 m)
Longest span20 ft (6.1 m)
Deck width29 ft (8.7 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,868 (2020)
Projected traffic3,154 by 2040
Trucks8%
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$348,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Jefferson Island over Deblanc Coulee built?

It was built in 1960, making it 65 years old in 2025.

What condition is Jefferson Island over Deblanc Coulee 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 October 2024.

How much traffic does Jefferson Island over Deblanc Coulee carry?

About 2,868 vehicles per day (2020 count), of which roughly 8% are trucks.

How long is Jefferson Island over Deblanc Coulee?

The structure is 100 ft (30.5 m) long with a longest span of 20 ft (6.1 m) and a deck 29 ft wide.

Who owns Jefferson Island over Deblanc Coulee?

It is owned by the County Highway Agency.