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 |
|---|---|---|---|---|---|
| LITTLE SHAWNEE CRK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1930 | 5,508 |
| DILLARD CREEK | Arkansas | Scour Critical — Countermeasures Ineffective | Fair | 1970 | 5,500 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 5,478 |
| Hackberry Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2000 | 5,453 |
| Hackberry Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2000 | 5,453 |
| EDINBURG MAIN CANAL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2014 | 5,451 |
| BRAZOS RIVER RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 5,432 |
| BRAZOS RIVER RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 5,432 |
| BRAZOS RIVER RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2023 | 5,432 |
| BRAZOS RIVER RELIEF DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 5,432 |
| Poindexter Branch | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 5,394 |
| PALMETTO CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1983 | 5,388 |
| ALDEN BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1994 | 5,375 |
| ALDEN BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1997 | 5,375 |
| DUCK CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1995 | 5,341 |
| BRAYS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1986 | 5,340 |
| BRAYS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1986 | 5,340 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1998 | 5,338 |
| LAKE TAWAKONI | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 5,311 |
| GUYANDOTTE RIVER | West Virginia | Scour Critical — Countermeasures Ineffective | Fair | 1971 | 5,300 |
| COWLEECH FORK SABINE | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1971 | 5,296 |
| GRAVEYARD BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1955 | 5,290 |
| BNSF/MTRLINK/EL TORO CRK | California | Scour Critical — Countermeasures Ineffective | Good | 2024 | 5,290 |
| DONNA DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 1995 | 5,278 |
| DRAINAGE DITCH 9A | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1963 | 5,273 |
| CIBOLO CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 5,252 |
| CIBOLO CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 5,252 |
| Drainage Ditch | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 5,238 |
| Hog Bayou | Texas | Scour Critical — Countermeasures Ineffective | Good | 1965 | 5,224 |
| BRAZOS RIVER RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Good | 2023 | 5,214 |
| WATER MINE BROOK | Massachusetts | Scour Critical — Countermeasures Ineffective | Fair | 1850 | 5,200 |
| STONE DAM CREEK | Arkansas | Scour Critical — Countermeasures Ineffective | Fair | 1935 | 5,200 |
| BRUSHY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2001 | 5,196 |
| RED BRANCH CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2001 | 5,196 |
| JERNIGAN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2016 | 5,190 |
| JERNIGAN CREEK RELIEF #2 | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 5,190 |
| JERNIGAN CREEK RELIEF #1 | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 5,190 |
| SMALL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1928 | 5,188 |
| JOHNS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 5,168 |
| DOCTORS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 5,168 |
| NORTH FLOODWAY CHANNEL | Texas | Scour Critical — Countermeasures Ineffective | Good | 2006 | 5,150 |
| SOUTH NOLAN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1961 | 5,150 |
| Corpus Christi Ship Chan | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2007 | 5,113 |
| Corpus Christi Ship Chan | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2002 | 5,113 |
| Corpus Christi Ship Chan | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2002 | 5,113 |
| Corpus Christi Ship Chan | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2002 | 5,113 |
| CHOCTAW CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1999 | 5,101 |
| CHOCTAW CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1999 | 5,101 |
| BRAYS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1951 | 5,100 |
| BRAYS BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1951 | 5,100 |
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.