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 |
|---|---|---|---|---|---|
| BIG BRUSHY CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1961 | 7,450 |
| SUWANNEE RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1963 | 7,450 |
| KALAMAZOO RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1908 | 7,449 |
| PESHASTIN CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1940 | 7,446 |
| PESHASTIN CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1962 | 7,446 |
| ST JOSEPH RIVER | Indiana | Scour Critical — Countermeasures Installed | Good | 1970 | 7,436 |
| MUSQUAPSINK BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1936 | 7,432 |
| FLEMMING CREEK | Michigan | Scour Critical — Countermeasures Installed | Poor | 1981 | 7,431 |
| PARIS CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1929 | 7,428 |
| HONEY CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1936 | 7,419 |
| Courtney Creek | Oregon | Scour Critical — Countermeasures Installed | Good | 1983 | 7,403 |
| EDSON BROOK | Connecticut | Scour Critical — Countermeasures Installed | Good | 1950 | 7,400 |
| ROCKY CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1961 | 7,400 |
| SOUTH TYGER RIVER | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1940 | 7,400 |
| CEDAR CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1935 | 7,400 |
| Spruce Creek | Florida | Scour Critical — Countermeasures Installed | Poor | 1962 | 7,400 |
| Canal C-100-A | Florida | Scour Critical — Countermeasures Installed | Fair | 1966 | 7,400 |
| MISSION CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1963 | 7,374 |
| BLACK DITCH CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1953 | 7,372 |
| WATER ABBOTT RUN RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1850 | 7,370 |
| BIG OX CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1995 | 7,352 |
| FROG CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1973 | 7,350 |
| FROG CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1973 | 7,350 |
| RIV RR PWRHS RD PASS RD | Kansas | Scour Critical — Countermeasures Installed | Good | 1978 | 7,343 |
| RIV RR PWRHS RD PASS RD | Kansas | Scour Critical — Countermeasures Installed | Good | 1979 | 7,343 |
| Senecal Creek | Oregon | Scour Critical — Countermeasures Installed | Good | 1985 | 7,340 |
| SO.BR RANCOCAS CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1918 | 7,337 |
| OVER SIXTEEN MILE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1941 | 7,330 |
| OPPOSSUM RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1947 | 7,326 |
| OVER MAHONING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Good | 1963 | 7,321 |
| NORFOLK SO. RR. | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1926 | 7,316 |
| NECANICUM RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 7,315 |
| MAMARONECK RIVER | New York | Scour Critical — Countermeasures Installed | Fair | 1910 | 7,311 |
| PUGET SOUND @ PT VASHON | Washington | Scour Critical — Countermeasures Installed | Fair | 1957 | 7,310 |
| Butte Creek Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1969 | 7,302 |
| S.FK.PAYETTE RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1955 | 7,300 |
| Intracoastal Waterway | Florida | Scour Critical — Countermeasures Installed | Fair | 1949 | 7,300 |
| EAST ASPETUCK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1931 | 7,300 |
| SALMON RIVER;SALMON BR. | Idaho | Scour Critical — Countermeasures Installed | Poor | 1926 | 7,300 |
| TRIBUTARY TO TROUT RIVER | Florida | Scour Critical — Countermeasures Installed | Good | 1986 | 7,300 |
| HIGHLANDS CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1986 | 7,300 |
| MAD RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1935 | 7,300 |
| BIG SOOS CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1931 | 7,293 |
| BULL CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1959 | 7,290 |
| ROGUE RIVER (WEDDERBURN) | Oregon | Scour Critical — Countermeasures Installed | Fair | 1930 | 7,286 |
| LITTLE SAND CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1972 | 7,285 |
| BROWNS BRANCH | Delaware | Scour Critical — Countermeasures Installed | Good | 1922 | 7,277 |
| CHEBOYGAN RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1940 | 7,273 |
| CAGUITAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Good | 2004 | 7,260 |
| Rogue River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1942 | 7,259 |
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.