US Bridges

County Road 6 over Granby Dam Spillway

Fair

Grand County, Colorado · 7.1 MI N of Granby CO · Structure no. ECA-BT-004

Built
1950
75 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Concrete
Length
75 ft
1 main span
Daily traffic
400
2019 count
Owner
Federal
Bureau of Reclamation

About this bridge

County Road 6 over Granby Dam Spillway is a concrete tee beam carrying County Road 6 over Granby Dam Spillway in Grand County, Colorado. It was built in 1950, so it is 75 years old, older 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 400 vehicles a day, roughly 3% of them trucks, projected to reach 500 by 2046. The structure is 75 ft (23 m) long and 26 ft wide. If it were closed, the detour would be 198.8 mi (320 km).

Location

Open in Google Maps
CarriesCounty Road 6
CrossesGranby Dam Spillway
Location7.1 MI N of Granby CO
RouteCounty Highway 0
CountyGrand County
StateColorado
Coordinates40.14777, -105.86597
Functional classRural Minor 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2023
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating57.9 US tons
Inventory rating27.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length75 ft (23 m)
Longest span71 ft (21.7 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic400 (2019)
Projected traffic500 by 2046
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed198.8 mi (320 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerBureau of Reclamation
Maintained byOther Local 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 6 over Granby Dam Spillway built?

It was built in 1950, making it 75 years old in 2025.

What condition is County Road 6 over Granby Dam Spillway 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 April 2023.

How much traffic does County Road 6 over Granby Dam Spillway carry?

About 400 vehicles per day (2019 count), of which roughly 3% are trucks.

How long is County Road 6 over Granby Dam Spillway?

The structure is 75 ft (23 m) long with a longest span of 71 ft (21.7 m) and a deck 26 ft wide.

Who owns County Road 6 over Granby Dam Spillway?

It is owned by the Bureau of Reclamation and maintained by the Other Local Agency.