US Bridges

County Road 21C over Jackson Ditch

Fair

Larimer County, Colorado · 0.4 MI N of CO RD 54G · Structure no. LR21C-0.4-54G-A

Built
1986
39 years old
Condition
Fair
inspected March 2025
Type
Culvert
Steel
Length
25 ft
1 main span
Daily traffic
772
2023 count
Owner
County
County Highway Agency

About this bridge

County Road 21C over Jackson Ditch is a steel culvert carrying County Road 21C over Jackson Ditch in Larimer County, Colorado. It was built in 1986, so it is 39 years old, younger than the Colorado average of 42.2 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 772 vehicles a day, roughly 24% of them trucks, projected to reach 965 by 2042. The structure is 25 ft (7.5 m) long and 68 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesCounty Road 21C
CrossesJackson Ditch
Location0.4 MI N of CO RD 54G
RouteCounty Highway 0
CountyLarimer County
StateColorado
Coordinates40.63264, -105.13797
Functional classUrban 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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 2025
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 adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating106.8 US tons
Inventory rating90.4 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans1
Design loadHS 20 + Mod
Structure length25 ft (7.5 m)
Longest span25 ft (7.5 m)
Deck width68 ft (20.8 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic772 (2023)
Projected traffic965 by 2042
Trucks24%
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 County Road 21C over Jackson Ditch built?

It was built in 1986, making it 39 years old in 2025.

What condition is County Road 21C over Jackson 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 2025.

How much traffic does County Road 21C over Jackson Ditch carry?

About 772 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is County Road 21C over Jackson Ditch?

The structure is 25 ft (7.5 m) long with a longest span of 25 ft (7.5 m) and a deck 68 ft wide.

Who owns County Road 21C over Jackson Ditch?

It is owned by the County Highway Agency.