US Bridges

Csah 20 over Willow Creek

Fair

Blue Earth County, Minnesota · 2.3 MI N of JCT TH 30 · Structure no. 07532

Built
1972
53 years old
Condition
Fair
inspected October 2023
Type
Channel Beam
Prestressed Concrete
Length
52 ft
1 main span
Daily traffic
400
2022 count
Owner
County
County Highway Agency

About this bridge

Csah 20 over Willow Creek is a prestressed concrete channel beam carrying Csah 20 over Willow Creek in Blue Earth County, Minnesota. It was built in 1972, so it is 53 years old, older than the Minnesota average of 38.5 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 400 vehicles a day, projected to reach 405 by 2042. The structure is 52 ft (15.7 m) long and 36 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesCsah 20
CrossesWillow Creek
Location2.3 MI N of JCT TH 30
RouteCounty Highway 20
CountyBlue Earth County
StateMinnesota
Coordinates43.92671, -94.23882
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
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 inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating62.6 US tons
Inventory rating37.4 US tons

Structure

Structure typeChannel Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length52 ft (15.7 m)
Longest span48 ft (14.6 m)
Deck width36 ft (11 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic400 (2022)
Projected traffic405 by 2042
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 Csah 20 over Willow Creek built?

It was built in 1972, making it 53 years old in 2025.

What condition is Csah 20 over Willow 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 2023.

How much traffic does Csah 20 over Willow Creek carry?

About 400 vehicles per day (2022 count).

How long is Csah 20 over Willow Creek?

The structure is 52 ft (15.7 m) long with a longest span of 48 ft (14.6 m) and a deck 36 ft wide.

Who owns Csah 20 over Willow Creek?

It is owned by the County Highway Agency.