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 |
|---|---|---|---|---|---|
| STONY RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1950 | 2,604 |
| WINNIPESAUKEE RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Good | 1988 | 2,602 |
| W FK DRY WOOD CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1935 | 2,601 |
| GOODBYS SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1938 | 2,600 |
| WATERWAY | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1930 | 2,600 |
| SMYRE CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1959 | 2,600 |
| LITTLE SALMON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1961 | 2,600 |
| CARICOSA CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1921 | 2,600 |
| FRANK AND POET DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,600 |
| TRUCKEE RIVER | Nevada | Scour Critical — Countermeasures Installed | Fair | 1978 | 2,600 |
| DRAW | Colorado | Scour Critical — Countermeasures Installed | Poor | 1938 | 2,600 |
| LITTLE SALMON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1962 | 2,600 |
| LITTLE SALMON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1962 | 2,600 |
| CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1965 | 2,600 |
| POCOTOPAUG CREEK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1929 | 2,600 |
| OROCOVIS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1927 | 2,600 |
| BURNT MILL CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1955 | 2,600 |
| BEACON HILL BROOK | Connecticut | Scour Critical — Countermeasures Installed | Good | 1933 | 2,600 |
| QUINEBAUG RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1931 | 2,600 |
| FOUR HOLE SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1975 | 2,600 |
| FOUR HOLE SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1975 | 2,600 |
| LAPILE CREEK | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1931 | 2,600 |
| SCOTTS CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1975 | 2,600 |
| EAST FORK WHITE RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1973 | 2,600 |
| TRIB TO 18 MI.CREEK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1980 | 2,600 |
| GRANDE DE MANATI RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1978 | 2,600 |
| LITTLE SALMON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1962 | 2,600 |
| PIGEON ROOST CR. | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1958 | 2,600 |
| BLACK RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,600 |
| UNCOMPAHGRE RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1966 | 2,600 |
| Creek | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1928 | 2,600 |
| GRANDE DE MAUNABO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1965 | 2,600 |
| Clabber Creek | Arkansas | Scour Critical — Countermeasures Installed | Poor | 1939 | 2,600 |
| BR BEAR CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1917 | 2,600 |
| CAIN CREEK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1935 | 2,600 |
| HOGANS CREEK | North Carolina | Scour Critical — Countermeasures Installed | Poor | 1967 | 2,600 |
| MAYO RIVER | North Carolina | Scour Critical — Countermeasures Installed | Poor | 1965 | 2,600 |
| SPRING CREEK | Idaho | Scour Critical — Countermeasures Installed | Good | 1962 | 2,600 |
| N BR RARITAN RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1934 | 2,598 |
| TRIB S BR PLUM CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 2,596 |
| BRENT RUN | Michigan | Scour Critical — Countermeasures Installed | Poor | 1926 | 2,595 |
| HARPETH RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1950 | 2,592 |
| LITTLE INDIAN CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 2,590 |
| BEAVER RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1920 | 2,589 |
| FRIDAY HBR-SAN JUAN CHAN | Washington | Scour Critical — Countermeasures Installed | Good | 2005 | 2,587 |
| ENGLISH CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1958 | 2,585 |
| DEER CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1967 | 2,585 |
| SIPSEY RIVER RELIEF | Alabama | Scour Critical — Countermeasures Installed | Fair | 1956 | 2,582 |
| SIPSEY RIVER | Alabama | Scour Critical — Countermeasures Installed | Fair | 1956 | 2,582 |
| LITTLE THORNAPPLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1942 | 2,581 |
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.