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 |
|---|---|---|---|---|---|
| MAD RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,340 |
| SUGAR CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,340 |
| Mid. Fk. Coquille River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 3,336 |
| Mid. Fk. Coquille River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 3,336 |
| Mid. Fk. Coquille River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 3,336 |
| BALL CREEK | Michigan | Scour Critical — Countermeasures Installed | Good | 2003 | 3,332 |
| NORTH FORK ASH CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1922 | 3,329 |
| ALLOWAYS CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1952 | 3,326 |
| LITTLE BULL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1900 | 3,323 |
| E.BR.BIG ELK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,323 |
| FIVE MILE CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1977 | 3,321 |
| BEAR CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1957 | 3,320 |
| BRAZOS RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,317 |
| Clear Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1931 | 3,317 |
| ALABAMA RIVER REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1983 | 3,316 |
| ALABAMA RIVER REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1983 | 3,316 |
| ALABAMA RIVER REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1983 | 3,316 |
| ALABAMA RIVER | Alabama | Scour Critical — Countermeasures Installed | Fair | 1985 | 3,316 |
| SILVER CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1929 | 3,310 |
| CLARK CR | Missouri | Scour Critical — Countermeasures Installed | Poor | 1965 | 3,308 |
| OVER WARREN RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1966 | 3,304 |
| TITTABAWASSEE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1958 | 3,302 |
| BEAVERDAM CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1969 | 3,300 |
| FOUR MILE CREEK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1990 | 3,300 |
| SHANKLIN CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,300 |
| FRANK AND POET DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1959 | 3,300 |
| BRUSHY CREEK | Mississippi | Scour Critical — Countermeasures Installed | Fair | 1958 | 3,300 |
| GUADIANA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,300 |
| MENG CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1981 | 3,300 |
| UNKNOWN CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1999 | 3,300 |
| UNKNOWN CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1999 | 3,300 |
| KANSAS RIVER & BNSF RR | Kansas | Scour Critical — Countermeasures Installed | Fair | 1964 | 3,300 |
| CRIMS CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1939 | 3,300 |
| DURHAM CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1960 | 3,300 |
| RUSSIAN RIVER - JIMTOWN | California | Scour Critical — Countermeasures Installed | Fair | 1949 | 3,300 |
| LUMAHAI STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,300 |
| WESTFIELD CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1936 | 3,300 |
| OVER BR. OF BEAVER RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1951 | 3,299 |
| W BR MIDDLE BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1964 | 3,299 |
| PIDCOCK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 3,292 |
| MILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1981 | 3,290 |
| BAYOU MOREAU | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1957 | 3,289 |
| TIMMONS DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1936 | 3,288 |
| HAWN CREEK | Oregon | Scour Critical — Countermeasures Installed | Poor | 1964 | 3,288 |
| LITTLE PIPE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1933 | 3,287 |
| OSAGE RVR | Missouri | Scour Critical — Countermeasures Installed | Poor | 1964 | 3,285 |
| OVERFLOW DUCK RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,281 |
| DUCK RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,281 |
| PENNYPACK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1883 | 3,280 |
| INDIAN CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1992 | 3,278 |
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.