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 |
|---|---|---|---|---|---|
| FIVE MILE CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1948 | 6,894 |
| BUFFALO BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1957 | 6,892 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1992 | 6,857 |
| ELAM BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1938 | 6,850 |
| TWELVEPOLE CREEK | West Virginia | Scour Critical — Countermeasures Ineffective | Poor | 1971 | 6,800 |
| LITTLE SUGAR CREEK | Arkansas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 6,800 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1995 | 6,787 |
| BOIS DARC CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1930 | 6,781 |
| CUTHAND CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1950 | 6,781 |
| WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1965 | 6,777 |
| HALFWAY HILLS WASH | California | Scour Critical — Countermeasures Ineffective | Fair | 2024 | 6,750 |
| DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 1984 | 6,727 |
| OYSTER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2012 | 6,724 |
| BULLHEAD SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2012 | 6,724 |
| OYSTER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2012 | 6,684 |
| BULLHEAD SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2012 | 6,684 |
| PHELPS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2009 | 6,682 |
| MUSTANG CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 6,658 |
| MILL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2006 | 6,650 |
| PINE CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1971 | 6,639 |
| PINE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1971 | 6,639 |
| PINE CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1971 | 6,639 |
| PINE CREEK DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1998 | 6,639 |
| ARROYO COLORADO | Texas | Scour Critical — Countermeasures Ineffective | Good | 1993 | 6,619 |
| SH 288 NB AND H SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 6,614 |
| MEDINA RIVER | Texas | Scour Critical — Countermeasures Ineffective | Good | 1977 | 6,608 |
| Trib 2 of Mound Crk | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 6,600 |
| Trib 2 of Mound Crk | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 6,600 |
| SALADO CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 6,584 |
| LONG BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1934 | 6,578 |
| NATURAL GROUND | Texas | Scour Critical — Countermeasures Ineffective | Good | 2011 | 6,570 |
| DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 1938 | 6,563 |
| DONNA MAIN CANAL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1949 | 6,554 |
| IRON ORE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1984 | 6,539 |
| JONES CR | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1922 | 6,515 |
| JONES CR SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1922 | 6,515 |
| DONNA DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1967 | 6,513 |
| S FORK OF CHACON CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1937 | 6,498 |
| GLADE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1950 | 6,493 |
| POST OAK CREEK TRIBUTARY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1962 | 6,470 |
| LITTLE VINCE BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1980 | 6,470 |
| LAKE RAY HUBBARD | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 6,460 |
| LAKE RAY HUBBARD | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 6,460 |
| ARMAND BAYOU TRIBUTARY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1994 | 6,434 |
| ARMAND BAYOU TRIBUTARY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1979 | 6,434 |
| FAULKEY GULLY | Texas | Scour Critical — Countermeasures Ineffective | Good | 1997 | 6,425 |
| Trib of Willow Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 2021 | 6,407 |
| Holder Branch | Texas | Scour Critical — Countermeasures Ineffective | Good | 2021 | 6,407 |
| Willow Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 2021 | 6,407 |
| Underwood Branch | Texas | Scour Critical — Countermeasures Ineffective | Good | 2021 | 6,407 |
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.