Scour Critical Bridges in Idaho
215 bridges in Idaho 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 215 bridges in Idaho have been identified as vulnerable to scour damage.
| Bridge | State | Scour Status | Condition | Year Built | ADT |
|---|---|---|---|---|---|
| SNAKE RIVER DRY BED | Idaho | Scour Critical — Countermeasures Installed | Fair | 1980 | 1,900 |
| CHIMNEY CR.;SHEEP CR. | Idaho | Scour Critical — Countermeasures Installed | Fair | 1961 | 1,900 |
| W.FK.SOLDIER CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1958 | 1,900 |
| SOLDIER CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1958 | 1,900 |
| JOHNSON CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1958 | 1,900 |
| KNOWLTON CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1958 | 1,900 |
| S.FK.COEUR DALENE RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1971 | 1,900 |
| ST MARIES RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1977 | 1,700 |
| CAMAS CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1963 | 1,700 |
| SNAKE R.;INDIAN COVE BR. | Idaho | Scour Critical — Countermeasures Installed | Fair | 1967 | 1,600 |
| SNAKE RIVER;GRANDVIEW BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1970 | 1,600 |
| BRUNEAU RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1955 | 1,500 |
| SNAKE R.(MONTGOMERY BR) | Idaho | Scour Critical — Countermeasures Installed | Poor | 1954 | 1,500 |
| S.FK.TETON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1959 | 1,500 |
| BIG WOOD RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1958 | 1,400 |
| PAYETTE RIVER;E.LETHA BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1960 | 1,400 |
| S.FK.COEUR DALENE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1949 | 1,400 |
| BEAR RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1960 | 1,300 |
| PACK RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1951 | 1,300 |
| CLEAR CREEK;AT LOWMAN | Idaho | Scour Critical — Countermeasures Installed | Fair | 1939 | 1,200 |
| THOMAS FORK CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1964 | 1,200 |
| SALMON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1954 | 1,100 |
| PAHSIMEROI RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1938 | 1,100 |
| S.FK.TETON RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1977 | 1,100 |
| N.FK.SNAKE R.;HIBBARD BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1968 | 1,000 |
| BOISE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1980 | 1,000 |
| PINE CREEK;WB ON RAMP | Idaho | Scour Critical — Countermeasures Installed | Fair | 1965 | 970 |
| COEUR DALENE RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1951 | 960 |
| ST JOE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1985 | 930 |
| BROWN CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1954 | 880 |
| PACK RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1941 | 870 |
| GROUSE CREEK | Idaho | Scour Critical — Countermeasures Installed | Poor | 1941 | 870 |
| SALMON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1985 | 800 |
| INDIAN CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1976 | 800 |
| BEAR RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1986 | 760 |
| YANKEE FK OF SALMON RIVR | Idaho | Scour Critical — Countermeasures Installed | Poor | 1934 | 680 |
| COEUR DALENE RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1936 | 680 |
| PAYETTE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1963 | 650 |
| CAMAS CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1955 | 630 |
| MINEAR CREEK | Idaho | Scour Critical — Countermeasures Installed | Poor | 1955 | 630 |
| KNOWLTON CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1955 | 630 |
| PINE CREEK;EB OFF RAMP | Idaho | Scour Critical — Countermeasures Installed | Fair | 1977 | 630 |
| CAPE HORN CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1964 | 620 |
| S.FK.BOISE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1963 | 620 |
| LIME CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1984 | 620 |
| CROOKED FK.CLEARWATER R. | Idaho | Scour Critical — Countermeasures Installed | Fair | 1960 | 610 |
| COEUR DALENE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1975 | 610 |
| PALOUSE R;SE.POTLATCH BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1965 | 580 |
| CASTLE CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1955 | 580 |
| BEAR RIVER;N.DINGLE BR. | Idaho | Scour Critical — Countermeasures Installed | Fair | 1966 | 560 |
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.