Scour Critical Bridges in Arizona
164 bridges in Arizona at risk from water erosion around foundations.
Scour Critical Bridges
Scour is the erosion of soil and rock around a bridge's foundation caused by moving water. When foundations are exposed or undermined, a bridge can collapse even if its deck and superstructure are in good condition. Scour is the leading cause of bridge failures in the US. These 164 bridges in Arizona have been identified as vulnerable to scour damage.
| Bridge | State | Scour Status | Condition | Year Built | ADT |
|---|---|---|---|---|---|
| BLACK CANYON WASH | Arizona | Scour Critical — Unaddressed | Poor | 1986 | 2,051 |
| LAGUNA CREEK | Arizona | Scour Critical — Unaddressed | Poor | 1965 | 150 |
| HUACHUCA CANYON CREEK | Arizona | Scour Critical — Countermeasures Ineffective | Good | 2021 | 300 |
| CORDUROY CREEK | Arizona | Scour Critical — Countermeasures Ineffective | Fair | 1973 | 40 |
| Indian Bend Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1979 | 57,843 |
| Grand Canal | Arizona | Scour Critical — Countermeasures Installed | Fair | 1979 | 52,404 |
| Cave Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1965 | 40,125 |
| Indian Bend Wash | Arizona | Scour Critical — Countermeasures Installed | Poor | 1976 | 37,601 |
| Cave Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1976 | 36,376 |
| Colorado River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1987 | 31,500 |
| Indian Bend Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1978 | 31,074 |
| Rillito Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1970 | 31,053 |
| Grand Canal | Arizona | Scour Critical — Countermeasures Installed | Fair | 1957 | 23,182 |
| Rillito River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1971 | 22,976 |
| Cave Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1958 | 20,381 |
| Ventana Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1967 | 17,470 |
| Arizona Canal | Arizona | Scour Critical — Countermeasures Installed | Fair | 1946 | 13,080 |
| Santa Cruz River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1953 | 11,577 |
| Pima Lateral Canal | Arizona | Scour Critical — Countermeasures Installed | Fair | 1920 | 11,494 |
| Lee Moore Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1973 | 11,193 |
| McClellan Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1960 | 10,511 |
| Santa Cruz Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1960 | 10,511 |
| Santa Cruz River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1960 | 10,449 |
| Cane Springs Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1961 | 10,203 |
| Natural Corral Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1961 | 10,203 |
| Granite Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1924 | 9,396 |
| Detrital Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1982 | 8,908 |
| Detrital Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1982 | 8,855 |
| Wilbur Canyon | Arizona | Scour Critical — Countermeasures Installed | Fair | 1963 | 8,346 |
| Ventana Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1987 | 7,758 |
| Granite Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1921 | 7,000 |
| Small Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1900 | 6,995 |
| Small Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1938 | 6,968 |
| San Simon River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1923 | 6,912 |
| Potrero Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1979 | 6,783 |
| Cherry Creek | Arizona | Scour Critical — Countermeasures Installed | Good | 1967 | 6,709 |
| Agua Fria River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1972 | 6,675 |
| Verde River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1975 | 6,328 |
| San Pedro River | Arizona | Scour Critical — Countermeasures Installed | Poor | 1960 | 6,156 |
| E Branch Brawley Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1957 | 5,668 |
| Cottonwood Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1948 | 5,460 |
| Rillito Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1963 | 5,205 |
| Niger Canyon | Arizona | Scour Critical — Countermeasures Installed | Fair | 1942 | 5,190 |
| Pinal Creek | Arizona | Scour Critical — Countermeasures Installed | Poor | 1920 | 5,162 |
| Wet Beaver Creek | Arizona | Scour Critical — Countermeasures Installed | Good | 1972 | 4,800 |
| Pinal Creek | Arizona | Scour Critical — Countermeasures Installed | Good | 1957 | 4,750 |
| Church Rock Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1961 | 4,533 |
| Dry Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1933 | 4,308 |
| Stronghold Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1933 | 4,308 |
| Dry Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1933 | 4,083 |
Scour Critical Rating Codes
| Code 2 — Unaddressed | Bridge is scour critical with no countermeasures installed. The foundation is vulnerable and no protective action has been taken. |
| Code 3 — Countermeasures Installed | Protective measures (riprap, sheet piling, etc.) have been installed to reduce scour risk, but the bridge remains classified as scour critical. |
| Code 6 — Countermeasures Ineffective | Protective measures were installed but have been assessed as ineffective. The bridge requires re-evaluation and additional action. |
About Scour Critical Bridges
Scour critical bridges have been identified through underwater inspection or analysis as having foundations that are unstable or could become unstable during flood conditions. FHWA requires action plans for all scour critical bridges. Famous scour failures include the 1987 Schoharie Creek Bridge collapse in New York.