US Bridges

Ia 9 over Inlet W Okoboji Lake

Fair

Dickinson County, Iowa · 0.4 Mi. E of Jct. Ia 86 · Structure no. 000000000023720

Built
1971
54 years old
Condition
Fair
inspected February 2023
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
8,500
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 9 over Inlet W Okoboji Lake is a concrete continuous culvert carrying Ia 9 over Inlet W Okoboji Lake in Dickinson County, Iowa. It was built in 1971, so it is 54 years old, older than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 8,500 vehicles a day, roughly 6% of them trucks, projected to reach 8,500 by 2042. The structure is 21 ft (6.4 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIa 9
CrossesInlet W Okoboji Lake
Location0.4 Mi. E of Jct. Ia 86
RouteState Highway 9
CountyDickinson County
StateIowa
Coordinates43.43035, -95.17245
Functional classUrban Other Principal 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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2023
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
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.4 US tons
Inventory rating24.8 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHS 20
Structure length21 ft (6.4 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,500 (2022)
Projected traffic8,500 by 2042
Trucks6%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Ia 9 over Inlet W Okoboji Lake built?

It was built in 1971, making it 54 years old in 2025.

What condition is Ia 9 over Inlet W Okoboji Lake 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 February 2023.

How much traffic does Ia 9 over Inlet W Okoboji Lake carry?

About 8,500 vehicles per day (2022 count), of which roughly 6% are trucks.

How long is Ia 9 over Inlet W Okoboji Lake?

The structure is 21 ft (6.4 m) long with a longest span of 10 ft (3 m).

Who owns Ia 9 over Inlet W Okoboji Lake?

It is owned by the State Highway Agency.