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 |
|---|---|---|---|---|---|
| PUGET SOUND @ SOUTHWORTH | Washington | Scour Critical — Countermeasures Installed | Good | 2003 | 3,681 |
| Calapooia River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,679 |
| Town Branch | Texas | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,678 |
| EAST BRANCH COXES CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Good | 1956 | 3,675 |
| M FORK WILDCAT CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1993 | 3,675 |
| HONEY CR DRAIN DTC | Missouri | Scour Critical — Countermeasures Installed | Fair | 1973 | 3,670 |
| MUD CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1949 | 3,660 |
| Mammoth Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1956 | 3,653 |
| TYLER CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1940 | 3,652 |
| TRIB.TULPEHOCKEN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 3,651 |
| SPANISH HOLLOW CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,651 |
| SPANISH HOLLOW CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,651 |
| SPANISH HOLLOW CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,651 |
| WATER MOSS BROOK | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1909 | 3,651 |
| SPANISH HOLLOW CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,651 |
| WAGNER CR./TALENT AVE. | Oregon | Scour Critical — Countermeasures Installed | Fair | 1914 | 3,649 |
| PINE KILL | New York | Scour Critical — Countermeasures Installed | Poor | 1928 | 3,645 |
| BEARSKIN CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Poor | 1932 | 3,642 |
| LITTLE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1985 | 3,639 |
| WHITMORE DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1956 | 3,633 |
| TURKEY CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1957 | 3,632 |
| BEAVER DAM CREEK | New York | Scour Critical — Countermeasures Installed | Good | 1994 | 3,631 |
| SONOMA CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1929 | 3,628 |
| BITTERROOT RIVER 010 | Montana | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,627 |
| WILLOW CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 3,627 |
| ARKANSAS RIVER | Kansas | Scour Critical — Countermeasures Installed | Good | 1980 | 3,622 |
| BIG CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1966 | 3,622 |
| AROOSTOOK RIV ABANDD RR | Maine | Scour Critical — Countermeasures Installed | Poor | 1956 | 3,620 |
| C STREET CANAL | Kansas | Scour Critical — Countermeasures Installed | Fair | 1950 | 3,620 |
| MILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1947 | 3,617 |
| NINEMILE CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1966 | 3,616 |
| MUSKEGON RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1977 | 3,615 |
| MILL CANAL | Rhode Island | Scour Critical — Countermeasures Installed | Good | 2018 | 3,603 |
| ARKANSAS RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1961 | 3,602 |
| FIRE PRAIRIE CR | Missouri | Scour Critical — Countermeasures Installed | Poor | 1984 | 3,602 |
| JAMES RV | South Dakota | Scour Critical — Countermeasures Installed | Poor | 1960 | 3,601 |
| SINCLAIR INLET | Washington | Scour Critical — Countermeasures Installed | Fair | 1990 | 3,600 |
| CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Good | 1965 | 3,600 |
| CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Good | 1965 | 3,600 |
| ROCK CREEK | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1953 | 3,600 |
| MIRAFLORES CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1929 | 3,600 |
| SOLOMON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1950 | 3,600 |
| DUEY RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1949 | 3,600 |
| TRIB TO PACOLET RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1973 | 3,600 |
| UNNAMED CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1950 | 3,600 |
| CARMEL RIVER | California | Scour Critical — Countermeasures Installed | Good | 1971 | 3,600 |
| PORTER SLOUGH | California | Scour Critical — Countermeasures Installed | Good | 1937 | 3,600 |
| LA PLATA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1991 | 3,600 |
| CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1976 | 3,600 |
| HIGUERO CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1986 | 3,600 |
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.