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 |
|---|---|---|---|---|---|
| BOISE RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1954 | 560 |
| SAND CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1982 | 550 |
| N.FK.PAYETTE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1969 | 550 |
| SALMON R;WHITEBIRD TRUSS | Idaho | Scour Critical — Countermeasures Installed | Poor | 1935 | 550 |
| BIG LOST RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1926 | 500 |
| PAYETTE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1961 | 480 |
| ST MARIES RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1955 | 460 |
| SNAKE R.;GLENNS FERRY BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1968 | 430 |
| S.FK.PAYETTE R;LOWMAN BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1948 | 410 |
| BEAR R.;GRACE-TURNER BR. | Idaho | Scour Critical — Countermeasures Installed | Fair | 1955 | 350 |
| N. FK. PAYETTE RIVER | Idaho | Scour Critical — Countermeasures Installed | Good | 1957 | 350 |
| MANNS CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1954 | 330 |
| N.FK.PAYETTE RIVER | Idaho | Scour Critical — Countermeasures Installed | Good | 1977 | 330 |
| POTLATCH RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1992 | 320 |
| PAYETTE RVR(MONTOUR BR) | Idaho | Scour Critical — Countermeasures Installed | Fair | 1967 | 310 |
| TROUT CREEK;N.BRANCH | Idaho | Scour Critical — Countermeasures Installed | Fair | 1957 | 300 |
| TETON RIVER | Idaho | Scour Critical — Countermeasures Installed | Good | 1976 | 300 |
| BEAR RIVER;BERN BRIDGE | Idaho | Scour Critical — Countermeasures Installed | Fair | 1973 | 300 |
| PINE CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1981 | 300 |
| SNAKE RVR(SLICK BRIDGE) | Idaho | Scour Critical — Countermeasures Installed | Fair | 1965 | 260 |
| BIG LOST RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1926 | 260 |
| TETON RIVER(CACHE BR) | Idaho | Scour Critical — Countermeasures Installed | Fair | 1956 | 250 |
| CANAL CREEK;PIERCE BR. | Idaho | Scour Critical — Countermeasures Installed | Good | 1975 | 210 |
| QUARTZ CREEK;THREE MILE | Idaho | Scour Critical — Countermeasures Installed | Fair | 1972 | 210 |
| DARBY CREEK | Idaho | Scour Critical — Countermeasures Installed | Good | 2014 | 200 |
| TETON RIVER(WHITE BR) | Idaho | Scour Critical — Countermeasures Installed | Fair | 1983 | 190 |
| MISSION CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1947 | 180 |
| FALL RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1983 | 180 |
| SAND CREEK | Idaho | Scour Critical — Countermeasures Installed | Good | 2010 | 160 |
| ST JOE RIVER;CALDER BR. | Idaho | Scour Critical — Countermeasures Installed | Fair | 1990 | 160 |
| A CANAL | Idaho | Scour Critical — Countermeasures Installed | Good | 2009 | 150 |
| BEAR R;CHEESECAKE FAC BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1975 | 140 |
| BEAR RIVER;E.DINGLE BR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1989 | 140 |
| MOYIE RIVER;MEADOW CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1928 | 120 |
| BEAVER CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1973 | 110 |
| CONANT CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1954 | 100 |
| PORTNEUF RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1945 | 100 |
| S.FK.BOISE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1961 | 90 |
| N.FK.PAYETTE RIVER | Idaho | Scour Critical — Countermeasures Installed | Poor | 1959 | 90 |
| LATOUR CREEK;SW.CATALDO | Idaho | Scour Critical — Countermeasures Installed | Fair | 1978 | 90 |
| LAPWAI CREEK | Idaho | Scour Critical — Countermeasures Installed | Good | 1963 | 80 |
| ROSE CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1990 | 80 |
| BEAR RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1984 | 70 |
| BRUNEAU RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1989 | 60 |
| CLOVER CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1915 | 50 |
| CLEAR CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 1974 | 50 |
| CRANE CREEK | Idaho | Scour Critical — Countermeasures Installed | Fair | 2015 | 50 |
| E.FK. OF S.FK.SALMON RVR | Idaho | Scour Critical — Countermeasures Installed | Fair | 1955 | 40 |
| CDA RIVER;SPRINGSTON BR | Idaho | Scour Critical — Countermeasures Installed | Poor | 1955 | 40 |
| TETON RVR (NICKERSON BR) | Idaho | Scour Critical — Countermeasures Installed | Good | 1990 | 40 |
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.