US Bridges

STC3787;SWAN Falls over Indian Creek

Fair

Ada County, Idaho · In Kuna · Structure no. 000000000026250

Built
1940
85 years old, rebuilt 1974
Condition
Fair
inspected October 2023
Type
Tee Beam
Prestressed Concrete
Length
119 ft
6 main spans
Daily traffic
7,800
2023 count
Owner
County
County Highway Agency

About this bridge

STC3787;SWAN Falls over Indian Creek is a prestressed concrete tee beam carrying STC3787;SWAN Falls over Indian Creek in Ada County, Idaho. It was built in 1940 and reconstructed in 1974, so it is 85 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 7,800 vehicles a day, roughly 26% of them trucks, projected to reach 11,700 by 2042. The structure is 119 ft (36.3 m) long and 32 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesSTC3787;SWAN Falls
CrossesIndian Creek
LocationIn Kuna
RouteCity Street 3787
CountyAda County
StateIdaho
Coordinates43.48733, -116.41381
Functional classUrban Minor Arterial

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 inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38 US tons
Inventory rating23 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length119 ft (36.3 m)
Longest span20 ft (6.1 m)
Deck width32 ft (9.8 m)
Roadway width29 ft (8.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,800 (2023)
Projected traffic11,700 by 2042
Trucks26%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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$2.3 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was STC3787;SWAN Falls over Indian Creek built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 1974.

What condition is STC3787;SWAN Falls over Indian Creek 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 2023.

How much traffic does STC3787;SWAN Falls over Indian Creek carry?

About 7,800 vehicles per day (2023 count), of which roughly 26% are trucks.

How long is STC3787;SWAN Falls over Indian Creek?

The structure is 119 ft (36.3 m) long with a longest span of 20 ft (6.1 m) and a deck 32 ft wide.

Who owns STC3787;SWAN Falls over Indian Creek?

It is owned by the County Highway Agency.