Scour Critical Bridges
23,522 bridges across the US 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 23,522 bridges have been identified as vulnerable to scour damage.
| Bridge | State | Scour Status | Condition | Year Built | ADT |
|---|---|---|---|---|---|
| THORNAPPLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1970 | 2,730 |
| HUBBLE CR OVRFL | Missouri | Scour Critical — Countermeasures Installed | Poor | 1936 | 2,729 |
| HUBBLE CR | Missouri | Scour Critical — Countermeasures Installed | Poor | 1936 | 2,729 |
| Beaver Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1966 | 2,725 |
| Butler Wash | Arizona | Scour Critical — Countermeasures Installed | Good | 1961 | 2,725 |
| GLADDENS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1927 | 2,723 |
| S F NINNESCAH RIVER | Kansas | Scour Critical — Countermeasures Installed | Good | 1988 | 2,720 |
| Santa Cruz River | Arizona | Scour Critical — Countermeasures Installed | Poor | 1959 | 2,718 |
| LITTLE BLUE RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1987 | 2,718 |
| CUNNINGHAM CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 2005 | 2,717 |
| SPRING GULLY | Texas | Scour Critical — Countermeasures Installed | Fair | 1980 | 2,715 |
| COQUILLE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,715 |
| COQUILLE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1965 | 2,715 |
| Beaver Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1936 | 2,713 |
| COWLITZ RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1948 | 2,712 |
| DAVIS CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1957 | 2,712 |
| COWLITZ R OVERFLOW | Washington | Scour Critical — Countermeasures Installed | Good | 1958 | 2,712 |
| Big Horn River | Wyoming | Scour Critical — Countermeasures Installed | Fair | 1957 | 2,711 |
| BAYOU AMY | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1968 | 2,711 |
| SALT CREEK | Oregon | Scour Critical — Countermeasures Installed | Poor | 1965 | 2,706 |
| ROBINSONS BRANCH RAH RIV | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1930 | 2,706 |
| CUYON RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1877 | 2,700 |
| CUYON RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1877 | 2,700 |
| PORTNEUF RIVER | Idaho | Scour Critical — Countermeasures Installed | Good | 1968 | 2,700 |
| WATER IPSWICH RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1861 | 2,700 |
| CEDAR DRAW | Idaho | Scour Critical — Countermeasures Installed | Fair | 1932 | 2,700 |
| BR YELLOW RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Poor | 1936 | 2,700 |
| OTTER CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1920 | 2,700 |
| MILL GUT TIDAL INLET | Rhode Island | Scour Critical — Countermeasures Installed | Poor | 1967 | 2,700 |
| EAST FORK ARKANSAS RIVER | Colorado | Scour Critical — Countermeasures Installed | Good | 2008 | 2,700 |
| WINHALL RIVER | Vermont | Scour Critical — Countermeasures Installed | Fair | 1936 | 2,700 |
| ALAMEDA CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1948 | 2,700 |
| DEEP CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1930 | 2,700 |
| BRANCH TO EDISTO RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1931 | 2,700 |
| Turner River | Florida | Scour Critical — Countermeasures Installed | Fair | 1949 | 2,700 |
| CORONACA CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1961 | 2,700 |
| N FK SCAPPOOSE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1957 | 2,700 |
| MEADOW CREEK | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1960 | 2,700 |
| MENG CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1969 | 2,700 |
| CEDAR CREEK #1 | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1982 | 2,700 |
| TURKEY QUARTER CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1967 | 2,700 |
| EIGHT MILE RIVER | Connecticut | Scour Critical — Countermeasures Installed | Good | 1986 | 2,700 |
| BEAVERDAM CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1962 | 2,700 |
| BIG BEAVERDAM CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1979 | 2,700 |
| WEST BR. BANTAM RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1961 | 2,700 |
| TRIB OF E BR CODORUS CR | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1941 | 2,695 |
| CHIPPEWANUCK CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1993 | 2,691 |
| FALL CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1976 | 2,690 |
| SAW MILL RIVER | New York | Scour Critical — Countermeasures Installed | Poor | 1902 | 2,690 |
| COON CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1986 | 2,688 |
Scour Critical Bridges by State
States ranked by number of scour critical bridges.
| State | Scour Critical | Unaddressed | Countermeasures | Ineffective |
|---|---|---|---|---|
| Texas | 3,912 | 75 | 516 | 3,321 |
| Pennsylvania | 2,233 | 45 | 2,187 | 1 |
| Louisiana | 1,302 | 13 | 1,288 | 1 |
| South Carolina | 1,263 | 0 | 1,217 | 46 |
| Oregon | 1,231 | 4 | 1,221 | 6 |
| Michigan | 1,081 | 14 | 1,062 | 5 |
| Nebraska | 962 | 224 | 732 | 6 |
| New York | 864 | 9 | 780 | 75 |
| Indiana | 756 | 7 | 749 | 0 |
| Wisconsin | 751 | 0 | 748 | 3 |
| Kansas | 638 | 9 | 626 | 3 |
| California | 623 | 27 | 562 | 34 |
| Tennessee | 581 | 12 | 569 | 0 |
| Washington | 516 | 14 | 487 | 15 |
| Puerto Rico | 496 | 9 | 487 | 0 |
| Alabama | 450 | 1 | 423 | 26 |
| Iowa | 392 | 3 | 385 | 4 |
| New Jersey | 362 | 2 | 360 | 0 |
| Florida | 357 | 4 | 339 | 14 |
| Oklahoma | 317 | 33 | 283 | 1 |
| Missouri | 312 | 4 | 307 | 1 |
| Mississippi | 301 | 6 | 286 | 9 |
| Connecticut | 279 | 0 | 276 | 3 |
| Minnesota | 257 | 38 | 202 | 17 |
| Vermont | 242 | 0 | 240 | 2 |
| Colorado | 241 | 3 | 238 | 0 |
| Idaho | 215 | 18 | 186 | 11 |
| South Dakota | 207 | 3 | 203 | 1 |
| Arkansas | 187 | 3 | 129 | 55 |
| Massachusetts | 166 | 15 | 106 | 45 |
| Montana | 166 | 13 | 140 | 13 |
| Arizona | 164 | 2 | 160 | 2 |
| West Virginia | 160 | 2 | 98 | 60 |
| Alaska | 159 | 1 | 146 | 12 |
| Maine | 140 | 13 | 126 | 1 |
| North Carolina | 130 | 9 | 105 | 16 |
| New Mexico | 127 | 4 | 114 | 9 |
| North Dakota | 102 | 14 | 87 | 1 |
| Utah | 100 | 6 | 82 | 12 |
| Georgia | 99 | 1 | 81 | 17 |
| Illinois | 99 | 3 | 85 | 11 |
| Nevada | 94 | 0 | 85 | 9 |
| Rhode Island | 94 | 0 | 93 | 1 |
| New Hampshire | 86 | 2 | 78 | 6 |
| Hawaii | 83 | 0 | 82 | 1 |
| Kentucky | 56 | 16 | 39 | 1 |
| Maryland | 54 | 1 | 51 | 2 |
| Wyoming | 51 | 1 | 48 | 2 |
| Delaware | 39 | 0 | 39 | 0 |
| Ohio | 12 | 2 | 4 | 6 |
| Virginia | 8 | 0 | 8 | 0 |
| District of Columbia | 5 | 0 | 4 | 1 |
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.