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 |
|---|---|---|---|---|---|
| Canal 078 | Florida | Scour Critical — Countermeasures Installed | Good | 1950 | 3,400 |
| WATER STONY BROOK | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1870 | 3,400 |
| CRUCES RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1952 | 3,400 |
| NORTH EDISTO RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,400 |
| PLACIDO BAYOU | Florida | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,400 |
| SAMMY SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1937 | 3,400 |
| Creek | Florida | Scour Critical — Countermeasures Installed | Fair | 1940 | 3,400 |
| GREAT BROOK | Vermont | Scour Critical — Countermeasures Installed | Fair | 1932 | 3,400 |
| GRANDE DE ARECIBO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1976 | 3,400 |
| HUTCHINSON CREEK | California | Scour Critical — Countermeasures Installed | Poor | 1952 | 3,400 |
| LYNCHES RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1961 | 3,400 |
| NEUSE RIVER | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,400 |
| AMES CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1960 | 3,399 |
| SOUTH POPLAR RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1913 | 3,392 |
| TRIB. TO MAHONING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1921 | 3,388 |
| E FORK TRINITY RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1985 | 3,383 |
| RAINY RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1954 | 3,382 |
| OVER OIL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1937 | 3,381 |
| ANGELICA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1927 | 3,378 |
| ANGELICA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1927 | 3,378 |
| WALNUT RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1988 | 3,377 |
| BNSF RR & RED OAK CRK | Texas | Scour Critical — Countermeasures Installed | Fair | 1987 | 3,377 |
| TRINITY RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1997 | 3,375 |
| Fortuna Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1933 | 3,375 |
| MICHIGAMME RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1958 | 3,375 |
| SEELEY DITCH | Oregon | Scour Critical — Countermeasures Installed | Good | 2006 | 3,373 |
| MISSISSINEWA RIVER | Indiana | Scour Critical — Countermeasures Installed | Poor | 1966 | 3,370 |
| MILL RACE | Delaware | Scour Critical — Countermeasures Installed | Fair | 1982 | 3,366 |
| BREAKNECK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1978 | 3,365 |
| AMITE R RELIEF | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,362 |
| LILLYS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,362 |
| LILLYS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,362 |
| OCHLOCKNEE RIVER O/F | Georgia | Scour Critical — Countermeasures Installed | Good | 1991 | 3,360 |
| OCHLOCKNEE RIVER | Georgia | Scour Critical — Countermeasures Installed | Good | 1991 | 3,360 |
| DRY BRANCH | Indiana | Scour Critical — Countermeasures Installed | Good | 1957 | 3,360 |
| SWATARA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1934 | 3,359 |
| POTTER POND CHANNEL | Rhode Island | Scour Critical — Countermeasures Installed | Good | 2002 | 3,358 |
| PETERS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1915 | 3,356 |
| DALTON RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1954 | 3,356 |
| WIGGINS BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1953 | 3,354 |
| Calapooia River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1937 | 3,351 |
| Creek | Oregon | Scour Critical — Countermeasures Installed | Poor | 1954 | 3,351 |
| HOG CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1933 | 3,350 |
| LITTLE WABASH RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1928 | 3,350 |
| HALL CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1914 | 3,348 |
| PEQUONNOCK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1916 | 3,343 |
| BEAR BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,342 |
| FRENCHTOWN BROOK | Rhode Island | Scour Critical — Countermeasures Installed | Good | 2012 | 3,341 |
| MCCOYS CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,341 |
| MAD RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,340 |
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.