US Bridges

446th Avenue over Lake Marsh Inlet

Fair

Hamlin County, South Dakota · 4W & 0.2N of Hayti · Structure no. 000000029100098

Built
1936
89 years old, rebuilt 1987
Condition
Fair
inspected July 2024
Type
Culvert
Concrete Continuous
Length
30 ft
2 main spans
Daily traffic
135
2022 count
Owner
County
County Highway Agency

About this bridge

446th Avenue over Lake Marsh Inlet is a concrete continuous culvert carrying 446th Avenue over Lake Marsh Inlet in Hamlin County, South Dakota. It was built in 1936 and reconstructed in 1987, so it is 89 years old, older than the South Dakota average of 48.9 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 135 vehicles a day, roughly 2% of them trucks, projected to reach 135 by 2032. The structure is 30 ft (9.1 m) long and 31 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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Carries446th Avenue
CrossesLake Marsh Inlet
Location4W & 0.2N of Hayti
RouteCounty Highway 0
CountyHamlin County
StateSouth Dakota
Coordinates44.66221, -97.28906
Functional classRural Major Collector

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 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 geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating36 US tons
Inventory rating27 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 10
Structure length30 ft (9.1 m)
Longest span11 ft (3.3 m)
Deck width31 ft (9.4 m)
Roadway width31 ft (9.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic135 (2022)
Projected traffic135 by 2032
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 446th Avenue over Lake Marsh Inlet built?

It was built in 1936, making it 89 years old in 2025. It was reconstructed in 1987.

What condition is 446th Avenue over Lake Marsh Inlet 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 July 2024.

How much traffic does 446th Avenue over Lake Marsh Inlet carry?

About 135 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is 446th Avenue over Lake Marsh Inlet?

The structure is 30 ft (9.1 m) long with a longest span of 11 ft (3.3 m) and a deck 31 ft wide.

Who owns 446th Avenue over Lake Marsh Inlet?

It is owned by the County Highway Agency.