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 |
|---|---|---|---|---|---|
| PLUM CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1970 | 8,539 |
| PLUM CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1970 | 8,539 |
| W. BR. NESHAMINY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1927 | 8,535 |
| LITTLE SWATARA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1966 | 8,530 |
| BRANCH MARTINS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1957 | 8,523 |
| HOUK DITCH | Indiana | Scour Critical — Countermeasures Installed | Good | 1988 | 8,521 |
| FISHING CREEK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1964 | 8,520 |
| BRANCH STONY CR/ 3256-A8 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1973 | 8,516 |
| CHAMBERS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1930 | 8,509 |
| MIDDLEBURY RIVER | Vermont | Scour Critical — Countermeasures Installed | Fair | 1964 | 8,500 |
| GUAJATACA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1978 | 8,500 |
| ROCK RIV& MADISON ST | Illinois | Scour Critical — Countermeasures Installed | Fair | 1925 | 8,500 |
| WILLOW SPRINGS WASH | California | Scour Critical — Countermeasures Installed | Poor | 1972 | 8,500 |
| BRUJO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 2002 | 8,500 |
| Miller Creek | Florida | Scour Critical — Countermeasures Installed | Poor | 1961 | 8,500 |
| GRANDE CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1984 | 8,500 |
| MORRO CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1921 | 8,500 |
| PASTILLO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1915 | 8,500 |
| MASHAMOQUET BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1929 | 8,500 |
| SANTA YNEZ RIVER | California | Scour Critical — Countermeasures Installed | Fair | 1939 | 8,500 |
| DO¥A DOLORES CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1945 | 8,500 |
| LOW BRANCH ROUGE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1935 | 8,500 |
| PEARL RIVER | Mississippi | Scour Critical — Countermeasures Installed | Fair | 1967 | 8,500 |
| UNNAMED CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1994 | 8,500 |
| CREEK | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1975 | 8,480 |
| SANDY RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1931 | 8,478 |
| TRIBUTARY MIDDLE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1941 | 8,477 |
| SHELTON DITCH | Oregon | Scour Critical — Countermeasures Installed | Fair | 1954 | 8,475 |
| BRANCH RIDLEY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1946 | 8,472 |
| MURDER CREEK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1953 | 8,472 |
| JOHNSON BRANCH | Indiana | Scour Critical — Countermeasures Installed | Good | 1940 | 8,470 |
| North Fork Wolf Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1938 | 8,468 |
| SOUCOOK RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1936 | 8,465 |
| Flat Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1933 | 8,459 |
| LITTLE BUFFALO CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1929 | 8,458 |
| PRAIRIE CREEK | Michigan | Scour Critical — Countermeasures Installed | Poor | 1929 | 8,456 |
| Big Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1951 | 8,456 |
| RIFLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1972 | 8,450 |
| WOLF RIVER | Tennessee | Scour Critical — Countermeasures Installed | Poor | 1949 | 8,449 |
| GREAT SOUTH BAY | New York | Scour Critical — Countermeasures Installed | Good | 1967 | 8,443 |
| GREAT SOUTH BAY | New York | Scour Critical — Countermeasures Installed | Fair | 1951 | 8,443 |
| POQUESSING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1970 | 8,438 |
| GILBERT CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1928 | 8,430 |
| W FORK LTL WILDCAT CR | Indiana | Scour Critical — Countermeasures Installed | Fair | 1986 | 8,417 |
| ANNSVILLE CREEK | New York | Scour Critical — Countermeasures Installed | Poor | 1927 | 8,410 |
| SCHUYLKILL RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1935 | 8,408 |
| Tomoka River | Florida | Scour Critical — Countermeasures Installed | Fair | 1968 | 8,400 |
| TOWN BRANCH | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1928 | 8,400 |
| MYAKKAHATCHEE CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1973 | 8,400 |
| MILLS CREEK | Michigan | Scour Critical — Countermeasures Installed | Good | 2023 | 8,400 |
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.