US Bridges

Heron Ave over Dry Mill Creek

FairPosted for load

Clayton County, Iowa · 093040406 · Structure no. 000000000119570

Built
1960
65 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
33 ft
1 main span
Daily traffic
82
2022 count
Owner
County
County Highway Agency

About this bridge

Heron Ave over Dry Mill Creek is a steel stringer/multi-beam or girder carrying Heron Ave over Dry Mill Creek in Clayton County, Iowa. It was built in 1960, so it is 65 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. Its operating status is: posted for load restriction.

It carries about 82 vehicles a day, projected to reach 82 by 2044. The structure is 33 ft (10.1 m) long and 21 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesHeron Ave
CrossesDry Mill Creek
Location093040406
RouteCounty Highway 0
CountyClayton County
StateIowa
Coordinates42.89556, -91.31954
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30.3 US tons
Inventory rating23.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length33 ft (10.1 m)
Longest span33 ft (10.1 m)
Deck width21 ft (6.5 m)
Roadway width20 ft (6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic82 (2022)
Projected traffic82 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 Heron Ave over Dry Mill Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is Heron Ave over Dry Mill 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 October 2024.

How much traffic does Heron Ave over Dry Mill Creek carry?

About 82 vehicles per day (2022 count).

How long is Heron Ave over Dry Mill Creek?

The structure is 33 ft (10.1 m) long with a longest span of 33 ft (10.1 m) and a deck 21 ft wide.

Who owns Heron Ave over Dry Mill Creek?

It is owned by the County Highway Agency.