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 |
|---|---|---|---|---|---|
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1989 | 1,000 |
| WEST CANAL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1953 | 1,000 |
| SEARS BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 1,000 |
| FOURPOLE CREEK | West Virginia | Scour Critical — Countermeasures Ineffective | Poor | 1940 | 1,000 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2000 | 1,000 |
| BIG CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1942 | 996 |
| DENTON CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1942 | 996 |
| SABINAL RIVER | Texas | Scour Critical — Countermeasures Ineffective | Good | 1987 | 992 |
| WILLAWALLA CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2007 | 990 |
| SABINE RIVER RELIEF NO 2 | Texas | Scour Critical — Countermeasures Ineffective | Good | 1996 | 986 |
| STOVALL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1985 | 984 |
| W. LITTLE POST OAK CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1929 | 983 |
| NEWTON CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2008 | 981 |
| RESERVOIR BROOK | Vermont | Scour Critical — Countermeasures Ineffective | Good | 2023 | 980 |
| COTTONWOOD CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1991 | 973 |
| FLAT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1996 | 973 |
| HUNGARY BROOK | Connecticut | Scour Critical — Countermeasures Ineffective | Good | 2023 | 970 |
| LYNN CRK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1965 | 970 |
| BIG CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 968 |
| SEYMOUR CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1971 | 967 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1999 | 966 |
| ELM CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1978 | 960 |
| ELM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1953 | 960 |
| CANEY CRK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1960 | 950 |
| ROCK CREEK RELIEF #3 | Texas | Scour Critical — Countermeasures Ineffective | Good | 1960 | 950 |
| ROCK CREEK RELIEF #2 | Texas | Scour Critical — Countermeasures Ineffective | Good | 1960 | 950 |
| ROCK CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1960 | 944 |
| LANDERS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1962 | 944 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2004 | 943 |
| Frio River | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1922 | 940 |
| LYNCH CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1951 | 940 |
| SHARPSTOWN DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1970 | 938 |
| SABINE RIVER | Texas | Scour Critical — Countermeasures Ineffective | Good | 1951 | 936 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1975 | 936 |
| BIG BLACK RIVER | Mississippi | Scour Critical — Countermeasures Ineffective | Fair | 1939 | 930 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1995 | 929 |
| CHOCTAW SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1949 | 923 |
| DELTA LAKE DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 1971 | 922 |
| Cache River | Arkansas | Scour Critical — Countermeasures Ineffective | Poor | 1948 | 920 |
| LITTLE VINCE BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1986 | 909 |
| Pepper Creek | Arkansas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 908 |
| WHISKEY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1934 | 906 |
| CUTHAND CREEK BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1951 | 906 |
| Little Sandy Cree | West Virginia | Scour Critical — Countermeasures Ineffective | Good | 2024 | 904 |
| LAKE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1970 | 903 |
| MAXWELL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1997 | 902 |
| SANDY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1984 | 902 |
| FOURPOLE CREEK | West Virginia | Scour Critical — Countermeasures Ineffective | Fair | 1925 | 900 |
| TRACE CREEK | West Virginia | Scour Critical — Countermeasures Ineffective | Good | 1986 | 900 |
| WATER MILL RIVER | Massachusetts | Scour Critical — Countermeasures Ineffective | Good | 1990 | 900 |
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.