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 |
|---|---|---|---|---|---|
| WILKESON CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1967 | 4,521 |
| KENTNER CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1975 | 4,519 |
| KENTNER CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1975 | 4,519 |
| DEN BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1924 | 4,517 |
| MCMICHAELS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 4,514 |
| RAMSEY CR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1930 | 4,514 |
| Snake River | Oregon | Scour Critical — Countermeasures Installed | Poor | 1953 | 4,512 |
| ROGUE RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1961 | 4,511 |
| SUGAR CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1965 | 4,510 |
| MATTAWOMAN CREEK | Maryland | Scour Critical — Countermeasures Installed | Fair | 1978 | 4,509 |
| BR.LITTLE PLUM CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1900 | 4,508 |
| Musgrove Creek | Alabama | Scour Critical — Countermeasures Installed | Fair | 1926 | 4,504 |
| OKANOGAN RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1950 | 4,504 |
| NECANICUM RV | Oregon | Scour Critical — Countermeasures Installed | Fair | 1952 | 4,501 |
| BLUFF CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1962 | 4,500 |
| BLUFF CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1962 | 4,500 |
| KING ARROYO | Colorado | Scour Critical — Countermeasures Installed | Fair | 1961 | 4,500 |
| Little River | Florida | Scour Critical — Countermeasures Installed | Poor | 1959 | 4,500 |
| LOS LLANOS CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1972 | 4,500 |
| JENKINTOWN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1936 | 4,500 |
| WEBSTER CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1920 | 4,500 |
| BRANCH CANYON | California | Scour Critical — Countermeasures Installed | Poor | 1943 | 4,500 |
| DAMIAN CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1945 | 4,500 |
| JUAN MARTIN CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1963 | 4,500 |
| TURKEY CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1966 | 4,500 |
| LOUSE CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1957 | 4,500 |
| BRUSHY CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1962 | 4,500 |
| CLARK CREEK | North Carolina | Scour Critical — Countermeasures Installed | Poor | 1964 | 4,500 |
| BROCKLISS SLOUGH | Nevada | Scour Critical — Countermeasures Installed | Good | 1952 | 4,500 |
| STREAM | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1901 | 4,500 |
| ARKANSAS RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1951 | 4,500 |
| NONEWAUG RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1957 | 4,500 |
| SEVEN MILE CREEK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1996 | 4,500 |
| SHRUB OAK BROOK | New York | Scour Critical — Countermeasures Installed | Fair | 1975 | 4,496 |
| M. FK. FORKED DEER RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1924 | 4,494 |
| MILL CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1960 | 4,484 |
| DRY CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1969 | 4,484 |
| REESE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 4,481 |
| MOREAU RVR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1974 | 4,478 |
| SMITH CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1929 | 4,478 |
| ELKHORN CR | Washington | Scour Critical — Countermeasures Installed | Fair | 1929 | 4,478 |
| HOGGATT BRANCH | Indiana | Scour Critical — Countermeasures Installed | Good | 2004 | 4,473 |
| LEONA RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1952 | 4,470 |
| TIPPECANOE RIVER | Indiana | Scour Critical — Countermeasures Installed | Good | 1952 | 4,468 |
| SIXES RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 4,463 |
| CRYSTAL CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 4,463 |
| DRAINAGE DITCH | Oregon | Scour Critical — Countermeasures Installed | Good | 1971 | 4,463 |
| OVER TRIB TO SUSQUEHANNA | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1921 | 4,462 |
| WEAVER RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 4,460 |
| BLACKWELL CR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,457 |
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.