US Bridges

Ia 12 over Drainage Ditch

Fair

Plymouth County, Iowa · 2.0 Mi. S of S JCT SR K18 · Structure no. 000000000039910

Built
1957
68 years old
Condition
Fair
inspected March 2023
Type
Culvert
Concrete Continuous
Length
29 ft
2 main spans
Daily traffic
1,940
2023 count
Owner
State
State Highway Agency

About this bridge

Ia 12 over Drainage Ditch is a concrete continuous culvert carrying Ia 12 over Drainage Ditch in Plymouth County, Iowa. It was built in 1957, so it is 68 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 1,940 vehicles a day, roughly 14% of them trucks, projected to reach 1,940 by 2043. The structure is 29 ft (8.8 m) long. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesIa 12
CrossesDrainage Ditch
Location2.0 Mi. S of S JCT SR K18
RouteState Highway 12
CountyPlymouth County
StateIowa
Coordinates42.60013, -96.49809
Functional classRural Minor 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 inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.7 US tons
Inventory rating19 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 20
Structure length29 ft (8.8 m)
Longest span14 ft (4.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,940 (2023)
Projected traffic1,940 by 2043
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 km)
TollOn a free road
National Highway SystemNo

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 12 over Drainage Ditch built?

It was built in 1957, making it 68 years old in 2025.

What condition is Ia 12 over Drainage Ditch 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 March 2023.

How much traffic does Ia 12 over Drainage Ditch carry?

About 1,940 vehicles per day (2023 count), of which roughly 14% are trucks.

How long is Ia 12 over Drainage Ditch?

The structure is 29 ft (8.8 m) long with a longest span of 14 ft (4.3 m).

Who owns Ia 12 over Drainage Ditch?

It is owned by the State Highway Agency.