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 |
|---|---|---|---|---|---|
| Houston Ship Channel | Texas | Scour Critical — Countermeasures Ineffective | Good | 1930 | 1,903 |
| CARTWRIGHT BRANCH | West Virginia | Scour Critical — Countermeasures Ineffective | Good | 1974 | 1,900 |
| ROBINETTE BRANCH | West Virginia | Scour Critical — Countermeasures Ineffective | Good | 1974 | 1,900 |
| GARY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 1,900 |
| TIMBER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1984 | 1,898 |
| RIO GRANDE RIVER | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1979 | 1,895 |
| HIDALGO W MAIN DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1989 | 1,888 |
| RAYMONDVILLE DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 1969 | 1,883 |
| WALNUT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1940 | 1,880 |
| FLINT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1927 | 1,868 |
| LITTLE VINCE BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1980 | 1,860 |
| FARMERS BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1968 | 1,860 |
| VINCE BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 1998 | 1,860 |
| BLACKS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 1,853 |
| FISHER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 1,853 |
| LITTLE WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1951 | 1,850 |
| WESLACO MAIN DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1960 | 1,844 |
| N IRRIGATION CANAL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1942 | 1,816 |
| RESACA DE LOS FRESNOS | Texas | Scour Critical — Countermeasures Ineffective | Good | 2001 | 1,800 |
| SULPHUR RIVER | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1973 | 1,797 |
| SULPHUR RIV REL 2 | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1973 | 1,797 |
| MUSTANG CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1987 | 1,797 |
| RICKETTS BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Poor | 1970 | 1,791 |
| China Ditch | Washington | Scour Critical — Countermeasures Ineffective | Poor | 2009 | 1,790 |
| RIPLEY CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1936 | 1,779 |
| LITTLE BEAR CREEK | Wyoming | Scour Critical — Countermeasures Ineffective | Fair | 2018 | 1,775 |
| Brooks Branch | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1981 | 1,774 |
| FRIO RIVER | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 1,766 |
| WILLOW FLATS | Texas | Scour Critical — Countermeasures Ineffective | Good | 2015 | 1,760 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1964 | 1,758 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1938 | 1,751 |
| GUM CREEK | Georgia | Scour Critical — Countermeasures Ineffective | Good | 1957 | 1,750 |
| PLUM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1942 | 1,745 |
| TANYARD CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1940 | 1,740 |
| WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1940 | 1,740 |
| CARROLL BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1940 | 1,740 |
| BOGGS GULLY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2000 | 1,740 |
| CIBOLO CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2002 | 1,737 |
| PECAN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 1,734 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1998 | 1,730 |
| PECAN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 1,730 |
| MILL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2005 | 1,729 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1966 | 1,728 |
| Salt Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1930 | 1,711 |
| Drainage Ditch | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1930 | 1,711 |
| ONION CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1928 | 1,704 |
| DOGWOOD CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1928 | 1,704 |
| IH10 EX-RP/WBFR/SH99SBFR | Texas | Scour Critical — Countermeasures Ineffective | Good | 2014 | 1,700 |
| VOGEL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2006 | 1,700 |
| Draw | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 1,688 |
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.