US Bridges

FM over Small Stream

Fair

Lyon County, Iowa · 099460702 · Structure no. 000000000230110

Built
1961
64 years old
Condition
Fair
inspected July 2023
Type
Culvert
Concrete Continuous
Length
20 ft
2 main spans
Daily traffic
450
2022 count
Owner
County
County Highway Agency

About this bridge

FM over Small Stream is a concrete continuous culvert carrying FM over Small Stream in Lyon County, Iowa. It was built in 1961, so it is 64 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 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 450 vehicles a day, projected to reach 450 by 2043. The structure is 20 ft (6.1 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesFM
CrossesSmall Stream
Location099460702
RouteCounty Highway 0
CountyLyon County
StateIowa
Coordinates43.41038, -96.32972
Functional classRural Major 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
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating57.1 US tons
Inventory rating34.2 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 20
Structure length20 ft (6.1 m)
Longest span10 ft (3 m)
Deck width32 ft (9.8 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic450 (2022)
Projected traffic450 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Small Stream built?

It was built in 1961, making it 64 years old in 2025.

What condition is FM over Small Stream 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 FM over Small Stream carry?

About 450 vehicles per day (2022 count).

How long is FM over Small Stream?

The structure is 20 ft (6.1 m) long with a longest span of 10 ft (3 m) and a deck 32 ft wide.

Who owns FM over Small Stream?

It is owned by the County Highway Agency.