Structure 15C0055 · Colusa County, CA
Carries Walnut Drive over Glenn-colusa Canal, 0.2 Mi W Zumwalt RD.
Set by its lowest-rated component: Deck and Superstructure at 6 of 9.
How ratings work23 ft end to end, longest span 11 ft. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a slab bridge.
| State | California |
| County | Colusa |
| Location | 0.2 Mi W Zumwalt RD |
| Carries | Walnut Drive |
| Crosses | Glenn-colusa Canal |
| Coordinates | 39.11955, -122.15618 |
| Material | Concrete Continuous |
| Design | Slab |
| Total Length | 23.0 ft (7 m) |
| Max Span | 11.2 ft (3.4 m) |
| Deck Width | 23.6 ft (7.2 m) |
| Deck Area | 50.4 sq m |
| Main Spans | 2 |
| Year Built | 1940 |
| Avg Daily Traffic | 650 (2015) |
| Truck Traffic | 10% |
| Lanes On Bridge | 2 |
| Last Inspection | December 2024 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 5 — Stable for scour |
| Structure Number | 15C0055 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.