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 |
|---|---|---|---|---|---|
| BALL CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1985 | 5,813 |
| PORTER CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1986 | 5,811 |
| OX SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Good | 2003 | 5,800 |
| UNKNOWN WATERWAY | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1980 | 5,800 |
| TRIB TO ENOREE RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1965 | 5,800 |
| NUEVE PASOS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1929 | 5,800 |
| CHEPACHET RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1920 | 5,800 |
| BRANCH APPLE CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Good | 1997 | 5,800 |
| SUWANNEE RIVER | Florida | Scour Critical — Countermeasures Installed | Good | 1971 | 5,800 |
| WENATCHEE RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1957 | 5,800 |
| NORTH BR.NESHAMINY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1931 | 5,796 |
| SYCAMORE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1975 | 5,795 |
| PACIFIC P L TAILRACE | Washington | Scour Critical — Countermeasures Installed | Good | 1934 | 5,794 |
| CLARKS RR PEMIGEWASSET R | New Hampshire | Scour Critical — Countermeasures Installed | Good | 1973 | 5,785 |
| BUSH CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1960 | 5,784 |
| TOBYS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1970 | 5,783 |
| ANTHRACITE CREEK | Washington | Scour Critical — Countermeasures Installed | Poor | 1940 | 5,782 |
| CONTOOCOOK RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Poor | 1942 | 5,773 |
| COMITE RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1965 | 5,772 |
| BONAPARTE CR | Washington | Scour Critical — Countermeasures Installed | Good | 1957 | 5,771 |
| MILL CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1936 | 5,770 |
| POLE CAT SLU | Missouri | Scour Critical — Countermeasures Installed | Fair | 1966 | 5,768 |
| GOSHENHOPPEN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1954 | 5,768 |
| RIPLEY CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1975 | 5,763 |
| HUNTING CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1950 | 5,761 |
| MACKVILLE CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1938 | 5,757 |
| ST MARYS RIVER | Indiana | Scour Critical — Countermeasures Installed | Poor | 1972 | 5,750 |
| RAFT RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1973 | 5,750 |
| RAFT RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1967 | 5,750 |
| S.FK.COEUR DALENE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1978 | 5,750 |
| S.FK.COEUR DALENE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1978 | 5,750 |
| ROCK RIVER | Illinois | Scour Critical — Countermeasures Installed | Poor | 1980 | 5,750 |
| NEOSHO RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1987 | 5,746 |
| HICKORY CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1987 | 5,746 |
| PARADISE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 5,745 |
| DOWAGIAC RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1953 | 5,743 |
| TEANAWAY R | Washington | Scour Critical — Countermeasures Installed | Fair | 1977 | 5,741 |
| BEAR RIVER | Maine | Scour Critical — Countermeasures Installed | Fair | 1929 | 5,738 |
| CHAMBERS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1977 | 5,736 |
| WISSAHICKON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1963 | 5,733 |
| TAYLORS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 5,723 |
| NAVASOTA RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1952 | 5,723 |
| WHITEWATER RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1986 | 5,720 |
| ANNA RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1978 | 5,715 |
| BRANDYWINE CREEK | Indiana | Scour Critical — Countermeasures Installed | Poor | 1955 | 5,707 |
| LITTLE BEAVER CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1938 | 5,703 |
| ROGERS POND | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1941 | 5,700 |
| PATTEE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1939 | 5,700 |
| WILLIAMS RIVER | Vermont | Scour Critical — Countermeasures Installed | Good | 1962 | 5,700 |
| ARENAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1905 | 5,700 |
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.