US Bridges

W 33rd South over Porter Canal

Fair

Bonneville County, Idaho · 1.6 S. 3.5 W. Idaho Falls · Structure no. 000000000031235

Built
1959
66 years old
Condition
Fair
inspected November 2024
Type
Frame
Concrete
Length
23 ft
1 main span
Daily traffic
1,400
2023 count
Owner
County
County Highway Agency

About this bridge

W 33rd South over Porter Canal is a concrete frame carrying W 33rd South over Porter Canal in Bonneville County, Idaho. It was built in 1959, so it is 66 years old, older than the Idaho average of 45.3 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 1,400 vehicles a day, roughly 8% of them trucks, projected to reach 2,100 by 2042. The structure is 23 ft (7 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesW 33rd South
CrossesPorter Canal
Location1.6 S. 3.5 W. Idaho Falls
RouteCounty Highway 0
CountyBonneville County
StateIdaho
Coordinates43.46797, -112.10706
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.
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be 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 rating30 US tons
Inventory rating18 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 15
Structure length23 ft (7 m)
Longest span23 ft (7 m)
Deck width30 ft (9.2 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,400 (2023)
Projected traffic2,100 by 2042
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$432,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was W 33rd South over Porter Canal built?

It was built in 1959, making it 66 years old in 2025.

What condition is W 33rd South over Porter Canal 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 W 33rd South over Porter Canal carry?

About 1,400 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is W 33rd South over Porter Canal?

The structure is 23 ft (7 m) long with a longest span of 23 ft (7 m) and a deck 30 ft wide.

Who owns W 33rd South over Porter Canal?

It is owned by the County Highway Agency.