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 |
|---|---|---|---|---|---|
| ELIZABETH CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 2005 | 3,470 |
| ROBINSON RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1980 | 3,469 |
| Siletz River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1956 | 3,467 |
| SISTER GROVE CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1975 | 3,466 |
| PHILLIPS CREEK (ELGIN) | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,466 |
| MAHANOY CREEK. | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1983 | 3,464 |
| BIG FISHDAM RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1936 | 3,462 |
| PANTHER CREEK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1952 | 3,462 |
| MILL BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1957 | 3,462 |
| MILL CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1987 | 3,458 |
| Crabtree Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1954 | 3,452 |
| COUNTY ROAD | Alabama | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,450 |
| ALABAMA RIVER REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,450 |
| ALABAMA RIVER REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,450 |
| ALABAMA RIVER REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,450 |
| ALABAMA RIVER REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,450 |
| ALABAMA RIVER | Alabama | Scour Critical — Countermeasures Installed | Fair | 1969 | 3,450 |
| Nashville Creek W Branch | Illinois | Scour Critical — Countermeasures Installed | Fair | 1921 | 3,450 |
| NNRR & E. SQUAW CREEK | Nevada | Scour Critical — Countermeasures Installed | Fair | 1974 | 3,450 |
| NNRR & E. SQUAW CREEK | Nevada | Scour Critical — Countermeasures Installed | Fair | 1974 | 3,450 |
| KANE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1959 | 3,442 |
| MAJADA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1984 | 3,442 |
| Stamford Mill River | New York | Scour Critical — Countermeasures Installed | Fair | 1930 | 3,441 |
| OVER SUGAR RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 3,441 |
| S FORK SABINE RIVER | Texas | Scour Critical — Countermeasures Installed | Good | 2006 | 3,440 |
| TRIB. HOKENDAUQUA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1932 | 3,436 |
| LTL INDIAN CR CSX RR | Indiana | Scour Critical — Countermeasures Installed | Fair | 1993 | 3,434 |
| SUMNER BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,433 |
| PRAIRIE CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1936 | 3,433 |
| WABASCON CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1929 | 3,430 |
| MARSHALL BRANCH CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1994 | 3,426 |
| MERCED RIVER | California | Scour Critical — Countermeasures Installed | Fair | 1928 | 3,425 |
| KNOB CREEK | Kentucky | Scour Critical — Countermeasures Installed | Fair | 1941 | 3,423 |
| Minto Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1934 | 3,423 |
| CATSKILL CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1825 | 3,422 |
| NEIL CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1966 | 3,421 |
| FLATWOODS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1977 | 3,420 |
| ST. JOHNS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1977 | 3,420 |
| EAGLE DRAW | New Mexico | Scour Critical — Countermeasures Installed | Fair | 1969 | 3,419 |
| MILL CREEK | Oregon | Scour Critical — Countermeasures Installed | Poor | 1966 | 3,417 |
| MONTOUR RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1950 | 3,416 |
| MERCED RIVER | California | Scour Critical — Countermeasures Installed | Poor | 1933 | 3,416 |
| WINNIPESAUKEE RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1982 | 3,412 |
| SALEM CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1919 | 3,406 |
| LITTLE JUNIATA RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1898 | 3,406 |
| KAWKAWLIN RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1928 | 3,404 |
| LITTLE WABASH RIVER | Indiana | Scour Critical — Countermeasures Installed | Good | 1986 | 3,404 |
| Creek | Florida | Scour Critical — Countermeasures Installed | Fair | 1940 | 3,400 |
| LYNCHES RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1961 | 3,400 |
| CRUCES RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1952 | 3,400 |
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.