FM over Porter Creek

FairPosted for load

Sac County, Iowa · 086383501 · Structure no. 000000000299740

Built: 1953; 72 years old
Condition: Fair; inspected August 2024
Type: Slab; Concrete Continuous
Length: 103 ft; 3 main spans
Daily traffic: 26; 2022 count
Owner: County; County Highway Agency

About this bridge

FM over Porter Creek is a concrete continuous slab carrying FM over Porter Creek in Sac County, Iowa. It was built in 1953, so it is 72 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. Its operating status is: posted for load restriction.

It carries about 26 vehicles a day, projected to reach 26 by 2044. The structure is 103 ft (31.4 m) long and 23 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesFM

CrossesPorter Creek

Location086383501

RouteCounty Highway 0

CountySac County

StateIowa

Coordinates42.22527, -95.24281

Functional classRural Minor Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

Component	Rating	Meaning
Deck	5 Fair	All primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure	5 Fair	All primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure	6 Satisfactory	Structural elements show some minor deterioration.
Channel and channel protection	6 Satisfactory	Structural elements show some minor deterioration.

Last inspectionAugust 2024

Inspection intervalevery 24 months

Operating statusPosted for load restriction

ScourFoundations stable; scour above top of footing

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 adequacy7: Better than present minimum criteria

Approach roadway alignment6: Equal to present minimum criteria

Operating rating30.6 US tons

Inventory rating15.5 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans3

Design loadH 15

Structure length103 ft (31.4 m)

Longest span39 ft (11.9 m)

Deck width23 ft (6.9 m)

Roadway width20 ft (6.1 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic26 (2022)

Projected traffic26 by 2044

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 proposedReplacement because of substandard load-carrying capacity or roadway geometry

Estimated improvement cost—

NavigationNo navigation control on waterway

Frequently asked questions

When was FM over Porter Creek built?

It was built in 1953, making it 72 years old in 2025.

What condition is FM over Porter 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 August 2024.

How much traffic does FM over Porter Creek carry?

About 26 vehicles per day (2022 count).

How long is FM over Porter Creek?

The structure is 103 ft (31.4 m) long with a longest span of 39 ft (11.9 m) and a deck 23 ft wide.

Who owns FM over Porter Creek?

It is owned by the County Highway Agency.