US Bridges

Zinnia over Rock Creek

Fair

Cerro Gordo County, Iowa · 095191305 · Structure no. 000000000105670

Built
1961
64 years old
Condition
Fair
inspected February 2024
Type
Culvert
Concrete
Length
34 ft
3 main spans
Daily traffic
265
2022 count
Owner
County
County Highway Agency

About this bridge

Zinnia over Rock Creek is a concrete culvert carrying Zinnia over Rock Creek in Cerro Gordo 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 265 vehicles a day, roughly 23% of them trucks, projected to reach 265 by 2044. The structure is 34 ft (10.4 m) long. If it were closed, the detour would be 11.8 mi (19 km).

Location

Open in Google Maps
CarriesZinnia
CrossesRock Creek
Location095191305
RouteCounty Highway 0
CountyCerro Gordo County
StateIowa
Coordinates43.03864, -93.02377
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
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 inspectionFebruary 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
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating61.4 US tons
Inventory rating49.5 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadH 20
Structure length34 ft (10.4 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 traffic265 (2022)
Projected traffic265 by 2044
Trucks23%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Zinnia over Rock Creek built?

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

What condition is Zinnia over Rock 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 February 2024.

How much traffic does Zinnia over Rock Creek carry?

About 265 vehicles per day (2022 count), of which roughly 23% are trucks.

How long is Zinnia over Rock Creek?

The structure is 34 ft (10.4 m) long with a longest span of 10 ft (3 m).

Who owns Zinnia over Rock Creek?

It is owned by the County Highway Agency.