Scour Critical Bridges in California
623 bridges in California 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 623 bridges in California have been identified as vulnerable to scour damage.
| Bridge | State | Scour Status | Condition | Year Built | ADT |
|---|---|---|---|---|---|
| OBAN DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| META DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| WALLA DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| WALLA DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| BEEHIVE DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| BEEHIVE DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| TARANTULA DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| ALTA DITCH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 10,700 |
| DRY CREEK CANAL | California | Scour Critical — Countermeasures Installed | Good | 1952 | 10,269 |
| HACIENDA WASH | California | Scour Critical — Countermeasures Installed | Poor | 1971 | 10,150 |
| HACIENDA WASH | California | Scour Critical — Countermeasures Installed | Fair | 1971 | 10,150 |
| SONOMA CREEK | California | Scour Critical — Countermeasures Installed | Good | 1949 | 9,700 |
| ARROYO GRANDE CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1932 | 9,600 |
| GALE DITCH | California | Scour Critical — Countermeasures Installed | Fair | 1969 | 9,500 |
| NEW CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1924 | 9,300 |
| COYOTE CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1930 | 9,275 |
| MISSION CHANNEL OVERFLOW | California | Scour Critical — Countermeasures Installed | Poor | 1966 | 9,000 |
| TANK FARM DITCH | California | Scour Critical — Countermeasures Installed | Good | 1988 | 8,803 |
| WHITEWATER RIVER | California | Scour Critical — Countermeasures Installed | Poor | 1950 | 8,700 |
| WILLOW SPRINGS WASH | California | Scour Critical — Countermeasures Installed | Poor | 1972 | 8,500 |
| SANTA YNEZ RIVER | California | Scour Critical — Countermeasures Installed | Fair | 1939 | 8,500 |
| MORRO CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1921 | 8,500 |
| RED WASH | California | Scour Critical — Countermeasures Installed | Good | 1967 | 8,150 |
| RED WASH | California | Scour Critical — Countermeasures Installed | Good | 1967 | 8,150 |
| MARK WEST CREEK | California | Scour Critical — Countermeasures Installed | Poor | 1958 | 8,000 |
| DRY CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1940 | 7,681 |
| SUTTER BYPASS | California | Scour Critical — Countermeasures Installed | Poor | 1938 | 7,600 |
| BLIND HILLS WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| ARDIS DITCH | California | Scour Critical — Countermeasures Installed | Poor | 1971 | 7,500 |
| WOODS WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| MCGINLEY WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| WOODS WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| NEWTON WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| ARDIS DITCH | California | Scour Critical — Countermeasures Installed | Fair | 1971 | 7,500 |
| HALFWAY HILLS WASH | California | Scour Critical — Countermeasures Installed | Fair | 1970 | 7,500 |
| BLIND HILLS WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| NEWTON WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| MCGINLEY WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| BLACK CYN WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| BLACK CYN WASH | California | Scour Critical — Countermeasures Installed | Poor | 1970 | 7,500 |
| TANK TOWER DITCH | California | Scour Critical — Countermeasures Installed | Poor | 1971 | 7,450 |
| WHALE MTN WASH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 7,450 |
| WHALE MTN WASH | California | Scour Critical — Countermeasures Installed | Good | 1966 | 7,450 |
| TANK TOWER DITCH | California | Scour Critical — Countermeasures Installed | Poor | 1971 | 7,450 |
| RICKEY DITCH OVERFLOW | California | Scour Critical — Countermeasures Installed | Good | 1965 | 6,950 |
| SAN ANTONIO CREEK | California | Scour Critical — Countermeasures Installed | Good | 1966 | 6,900 |
| SAN ANTONIO CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1966 | 6,900 |
| DRY CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1958 | 6,877 |
| SPANISH CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1964 | 6,700 |
| VIEJAS CREEK | California | Scour Critical — Countermeasures Installed | Good | 1933 | 6,575 |
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.