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 |
|---|---|---|---|---|---|
| CUTHAND CREEK BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1951 | 364 |
| MULBERRY CR | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 362 |
| WILLACY MAIN CANAL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2007 | 358 |
| DUCK CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1976 | 357 |
| MAXWELL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2003 | 356 |
| MALLORY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1956 | 356 |
| DUGAN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1959 | 354 |
| WEST YEGUA CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 353 |
| CEDAR CREEK | Georgia | Scour Critical — Countermeasures Ineffective | Good | 2023 | 350 |
| MOORES CREEK | Alabama | Scour Critical — Countermeasures Ineffective | Poor | 1910 | 350 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1967 | 350 |
| MOUND CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1999 | 350 |
| VALLEY FORK | West Virginia | Scour Critical — Countermeasures Ineffective | Fair | 1985 | 350 |
| N SULPHUR RIVER | Texas | Scour Critical — Countermeasures Ineffective | Good | 2010 | 350 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 2008 | 347 |
| ROCK CREEK RELIEF #1 | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2001 | 345 |
| DURHAM BR | Texas | Scour Critical — Countermeasures Ineffective | Good | 1951 | 345 |
| MIDDLE SULPHUR RIVER | Texas | Scour Critical — Countermeasures Ineffective | Good | 2002 | 341 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1938 | 340 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1938 | 340 |
| MORGAN BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1938 | 340 |
| MUSTANG BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 2010 | 340 |
| MALLORY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2003 | 336 |
| SHOOTER CR | Texas | Scour Critical — Countermeasures Ineffective | Good | 2006 | 332 |
| CEDAR CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1985 | 330 |
| CANEY CRK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1967 | 330 |
| DENTON CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1963 | 330 |
| Loring Creek Relief | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1949 | 329 |
| BOIS DARC CRK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1991 | 328 |
| DRY FORK LITTLE WICHITA | Texas | Scour Critical — Countermeasures Ineffective | Good | 1964 | 328 |
| KING CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1991 | 328 |
| ALLEN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1943 | 327 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1938 | 325 |
| PARKER CREEK NO 2 | Texas | Scour Critical — Countermeasures Ineffective | Good | 1968 | 324 |
| PARKERS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1968 | 324 |
| CYPRESS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 320 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1972 | 320 |
| N TONK BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2008 | 318 |
| CHIAMON CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Good | 2004 | 316 |
| ANDERSON CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1951 | 315 |
| LAKE NOCONA SPILLWAY | Texas | Scour Critical — Countermeasures Ineffective | Good | 1997 | 313 |
| HORSE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1967 | 313 |
| ALABAMA CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2022 | 312 |
| PERSIMMON CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1997 | 310 |
| ELM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1966 | 310 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 309 |
| Drainage Ditch | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 309 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2020 | 309 |
| SALITRILLO CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 309 |
| DENTON CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1966 | 309 |
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.