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 |
|---|---|---|---|---|---|
| Bullhead Slough | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1994 | 7,963 |
| POOR FARM DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1959 | 7,960 |
| POOR FARM DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1959 | 7,960 |
| SPRING CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1996 | 7,955 |
| WALLER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1934 | 7,914 |
| WHITE OAK BAYOU TRIB | Texas | Scour Critical — Countermeasures Ineffective | Good | 1987 | 7,870 |
| WHITE OAK BAYOU TRIB | Texas | Scour Critical — Countermeasures Ineffective | Good | 1987 | 7,870 |
| CAMP CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1961 | 7,867 |
| Gum Gully | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 7,864 |
| HORSE PEN CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1964 | 7,856 |
| HORSE PEN CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1964 | 7,856 |
| CANAL | Texas | Scour Critical — Countermeasures Ineffective | Good | 1989 | 7,856 |
| HORSE PEN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1964 | 7,856 |
| BURNT BOOT CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1938 | 7,830 |
| JACK CREEK TRIBUTARY | Texas | Scour Critical — Countermeasures Ineffective | Good | 1983 | 7,828 |
| HCFCD M121-00-00 | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 7,821 |
| HCFCD M121-00-00 | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 7,821 |
| CARPENTERS BAYOU TRIB | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1940 | 7,803 |
| MOORE CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1961 | 7,781 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1928 | 7,751 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1925 | 7,724 |
| ROCK CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2010 | 7,720 |
| ROCK CREEK TRIB | Texas | Scour Critical — Countermeasures Ineffective | Good | 2011 | 7,720 |
| DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 7,718 |
| SPRING BRANCH RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Good | 1993 | 7,714 |
| GOOSE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1959 | 7,700 |
| S FORK SABINE RIVER | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1959 | 7,628 |
| DUNBAR CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1952 | 7,615 |
| LITTLE ELM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1955 | 7,607 |
| LITTLE ELM CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1955 | 7,607 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1962 | 7,600 |
| Orchard Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 1981 | 7,564 |
| TIMBER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1989 | 7,519 |
| TIMBER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1989 | 7,519 |
| IH 10 BW 8 CONNECTORS | Texas | Scour Critical — Countermeasures Ineffective | Good | 1994 | 7,500 |
| DRY GULLY | Texas | Scour Critical — Countermeasures Ineffective | Good | 1994 | 7,500 |
| MILL CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Good | 1982 | 7,495 |
| MILL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1982 | 7,495 |
| HALL BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1948 | 7,490 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1999 | 7,486 |
| SOUTH DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 7,480 |
| NORTH DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 7,480 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1998 | 7,472 |
| FRIO RIVER RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Good | 1957 | 7,458 |
| POESTA CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1976 | 7,410 |
| SIMS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 2008 | 7,400 |
| SIMS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 2008 | 7,400 |
| WEST CADDO SLOUGH NORTH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2000 | 7,396 |
| WEST CADDO CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2000 | 7,396 |
| BUFFALO BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1938 | 7,344 |
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.