US Bridges

US 20 & Ia 17 over Waterway

Fair

Hamilton County, Iowa · 2.1 MI E of W JCT Ia 17 · Structure no. 000000000604330

Built
1977
48 years old
Condition
Fair
inspected July 2023
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
11,200
2022 count
Owner
State
State Highway Agency

About this bridge

US 20 & Ia 17 over Waterway is a concrete continuous culvert carrying US 20 & Ia 17 over Waterway in Hamilton County, Iowa. It was built in 1977, so it is 48 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 11,200 vehicles a day, roughly 25% of them trucks, projected to reach 11,200 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

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CarriesUS 20 & Ia 17
CrossesWaterway
Location2.1 MI E of W JCT Ia 17
RouteU.S. Route 20
CountyHamilton County
StateIowa
Coordinates42.4491, -93.86679
Functional classRural Principal Arterial - Other

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 protection9 ExcellentNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.3 US tons
Inventory rating26.5 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 traffic11,200 (2022)
Projected traffic11,200 by 2042
Trucks25%
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 US 20 & Ia 17 over Waterway built?

It was built in 1977, making it 48 years old in 2025.

What condition is US 20 & Ia 17 over Waterway 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 July 2023.

How much traffic does US 20 & Ia 17 over Waterway carry?

About 11,200 vehicles per day (2022 count), of which roughly 25% are trucks.

How long is US 20 & Ia 17 over Waterway?

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

Who owns US 20 & Ia 17 over Waterway?

It is owned by the State Highway Agency.