US Bridges

Local over Knotty Creek

Fair

Des Moines County, Iowa · 070031205 · Structure no. 000000000143120

Built
1900
125 years old
Condition
Fair
inspected September 2024
Type
Slab
Steel
Length
42 ft
1 main span
Daily traffic
26
2022 count
Owner
County
County Highway Agency

About this bridge

Local over Knotty Creek is a steel slab carrying Local over Knotty Creek in Des Moines County, Iowa. It was built in 1900, so it is 125 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 26 vehicles a day, projected to reach 26 by 2044. The structure is 42 ft (12.8 m) long and 21 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesLocal
CrossesKnotty Creek
Location070031205
RouteCounty Highway 0
CountyDes Moines County
StateIowa
Coordinates40.87029, -91.15131
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
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
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating57.7 US tons
Inventory rating34.6 US tons

Structure

Structure typeSlab
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length42 ft (12.8 m)
Longest span41 ft (12.5 m)
Deck width21 ft (6.4 m)
Roadway width21 ft (6.4 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 closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Local over Knotty Creek built?

It was built in 1900, making it 125 years old in 2025.

What condition is Local over Knotty 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 September 2024.

How much traffic does Local over Knotty Creek carry?

About 26 vehicles per day (2022 count).

How long is Local over Knotty Creek?

The structure is 42 ft (12.8 m) long with a longest span of 41 ft (12.5 m) and a deck 21 ft wide.

Who owns Local over Knotty Creek?

It is owned by the County Highway Agency.