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 |
|---|---|---|---|---|---|
| IRRIGATION CANAL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1949 | 10,162 |
| PARKER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1996 | 10,155 |
| BRICKHOUSE GULLY | Texas | Scour Critical — Countermeasures Ineffective | Good | 1968 | 10,150 |
| BUS77 UPRR & PRIMERA RD | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1967 | 10,110 |
| HICKORY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1980 | 10,098 |
| PAINT CREEK | Michigan | Scour Critical — Countermeasures Ineffective | Good | 2024 | 10,078 |
| PANTHER BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2000 | 10,038 |
| US 181 and Drainage Chan | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 10,017 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1993 | 10,000 |
| RELIEF FOR CANAL | Mississippi | Scour Critical — Countermeasures Ineffective | Fair | 1976 | 10,000 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 10,000 |
| WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1958 | 10,000 |
| PANTHER BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1999 | 10,000 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 10,000 |
| SIMS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1989 | 10,000 |
| WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1958 | 10,000 |
| HUNTING BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1960 | 10,000 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1997 | 10,000 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1993 | 10,000 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1998 | 10,000 |
| DRY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1987 | 9,959 |
| GRAPEVINE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2002 | 9,956 |
| NEAL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1950 | 9,954 |
| BANITA CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1935 | 9,912 |
| Seaborne Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 2015 | 9,900 |
| MOUND CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1972 | 9,890 |
| COUNTRY CLUB BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1950 | 9,800 |
| PEACH CR & MARE BR | Texas | Scour Critical — Countermeasures Ineffective | Good | 2007 | 9,774 |
| ARROYO COLORADO | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1957 | 9,768 |
| HALLS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 2011 | 9,685 |
| LEWIS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1972 | 9,679 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1988 | 9,676 |
| RAYMONDVILLE DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2014 | 9,649 |
| RAYMONDVILLE DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2014 | 9,649 |
| ARROYO LOS OLMOS | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 9,622 |
| PLUM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1940 | 9,620 |
| LK CONROE/W FK SN JAC RI | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1972 | 9,618 |
| BERESFORD CREEK | South Carolina | Scour Critical — Countermeasures Ineffective | Good | 2024 | 9,600 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1949 | 9,600 |
| OCMULGEE RIVER | Georgia | Scour Critical — Countermeasures Ineffective | Good | 2023 | 9,600 |
| PANTHER BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1992 | 9,560 |
| DUCK CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1988 | 9,554 |
| BEAR CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1968 | 9,549 |
| WEST CADDO SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2000 | 9,542 |
| RIO GRANDE RIVER | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1994 | 9,525 |
| MULBERRY CREEK BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1950 | 9,490 |
| MULBERRY CREEK BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1950 | 9,490 |
| CRYSTAL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2010 | 9,461 |
| DRY COMAL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1938 | 9,457 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1961 | 9,454 |
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.