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 |
|---|---|---|---|---|---|
| Pond Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 1986 | 2,616 |
| Spring Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1986 | 2,616 |
| Elm Fork of Trinity | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1986 | 2,616 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1940 | 2,607 |
| Buck Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1951 | 2,607 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1951 | 2,607 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1951 | 2,607 |
| CHIMNEY ROCK DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1963 | 2,600 |
| ANTELOPE CREEK | California | Scour Critical — Countermeasures Ineffective | Fair | 2002 | 2,600 |
| BRICKHOUSE GULLY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1966 | 2,590 |
| Rabbs Bayou | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1963 | 2,587 |
| ROWLETT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2009 | 2,576 |
| Timber Creek Relief | Texas | Scour Critical — Countermeasures Ineffective | Good | 1969 | 2,574 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1965 | 2,573 |
| HCFCD DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1998 | 2,572 |
| BLACK CREEK | New York | Scour Critical — Countermeasures Ineffective | Good | 2024 | 2,566 |
| Indian Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1964 | 2,555 |
| Truckee Canal | Nevada | Scour Critical — Countermeasures Ineffective | Good | 2024 | 2,550 |
| RUSSELL CREEK | Ohio | Scour Critical — Countermeasures Ineffective | Good | 2024 | 2,547 |
| KIRKWOOD BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2002 | 2,540 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1984 | 2,540 |
| GUM BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 1984 | 2,530 |
| INDIAN CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1990 | 2,530 |
| Big Cypress Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1970 | 2,526 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1980 | 2,522 |
| DUCK CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1962 | 2,516 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1954 | 2,503 |
| LANGHAM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2006 | 2,500 |
| MACHINE CREEK | South Carolina | Scour Critical — Countermeasures Ineffective | Good | 2024 | 2,500 |
| ARMAND BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 2001 | 2,500 |
| GUYANDOTTE RIVER | West Virginia | Scour Critical — Countermeasures Ineffective | Fair | 1997 | 2,500 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 2008 | 2,500 |
| SEALS GULLY | Texas | Scour Critical — Countermeasures Ineffective | Good | 2002 | 2,500 |
| ARMAND BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 2001 | 2,500 |
| Arroyo Burro | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1953 | 2,494 |
| SAW KILL | New York | Scour Critical — Countermeasures Ineffective | Good | 2024 | 2,489 |
| SALT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 2,485 |
| SALT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1987 | 2,485 |
| ELM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1954 | 2,483 |
| MILL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1925 | 2,478 |
| SALT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1958 | 2,478 |
| MUSTANG CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1930 | 2,464 |
| VARNER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 2,456 |
| VARNER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 2,456 |
| MARYS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2008 | 2,450 |
| WHITE OAK CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1988 | 2,426 |
| WHITE OAK CRK REL #3 | Texas | Scour Critical — Countermeasures Ineffective | Good | 1988 | 2,426 |
| RAWHIDE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1977 | 2,424 |
| ELM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1986 | 2,421 |
| CLENDINING CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1941 | 2,420 |
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.