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 |
|---|---|---|---|---|---|
| WHITE RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1974 | 4,260 |
| SANTA ISABEL CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 2000 | 4,260 |
| COOKS BROOK | Maine | Scour Critical — Countermeasures Installed | Fair | 1932 | 4,258 |
| MARION DRAIN CANAL | Washington | Scour Critical — Countermeasures Installed | Good | 1931 | 4,257 |
| ELDER CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1966 | 4,257 |
| EVANS CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1962 | 4,256 |
| MILLERS BRANCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1931 | 4,256 |
| BROOKSHIRE CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1988 | 4,254 |
| NEWTOWN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1796 | 4,254 |
| DRAIN | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1951 | 4,251 |
| BAYOU GRAND CANE | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1951 | 4,251 |
| B.GRAND CANE RLF | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1951 | 4,251 |
| SILVER CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1933 | 4,248 |
| M BR PINE RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1952 | 4,242 |
| Tumble Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1949 | 4,241 |
| FADES CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1932 | 4,241 |
| MUD CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1981 | 4,240 |
| SKINNER DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1978 | 4,238 |
| GRAND RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1978 | 4,238 |
| GRAND RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1978 | 4,238 |
| SKINNER DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1978 | 4,238 |
| SEQUATCHIE RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1980 | 4,237 |
| QUAKAKE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1927 | 4,225 |
| SALT CREEK | New Mexico | Scour Critical — Countermeasures Installed | Fair | 1974 | 4,224 |
| YELLOW RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,219 |
| KENT RUN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1940 | 4,215 |
| WATER SCORTON RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1926 | 4,214 |
| SOUTH UMPQUA RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1989 | 4,214 |
| PACHAUG RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1951 | 4,214 |
| ARKANSAS RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1957 | 4,206 |
| PINE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1932 | 4,202 |
| ROCK RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1954 | 4,201 |
| ABITA RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1983 | 4,200 |
| ALAPAHA RIVER OVERFLOW | Florida | Scour Critical — Countermeasures Installed | Fair | 1922 | 4,200 |
| BIMINI CANAL | Florida | Scour Critical — Countermeasures Installed | Good | 1960 | 4,200 |
| DEPRESSION SMALL STREAM | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1925 | 4,200 |
| FOWLER SWITCH CANAL | California | Scour Critical — Countermeasures Installed | Fair | 1938 | 4,200 |
| GUAYO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1961 | 4,200 |
| BROCKWAY CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1932 | 4,200 |
| YAMPA RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1967 | 4,200 |
| ANON CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1922 | 4,200 |
| MARICAO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1983 | 4,200 |
| ROCK RIVER | Illinois | Scour Critical — Countermeasures Installed | Poor | 1966 | 4,200 |
| MARIA BAYOU TRIB. #3 | Louisiana | Scour Critical — Countermeasures Installed | Good | 2011 | 4,200 |
| KALAMAZOO RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1950 | 4,200 |
| SWARTZ CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1969 | 4,200 |
| SHEPAUG RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1950 | 4,200 |
| ARENAS CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1933 | 4,200 |
| HAMILTON CR | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1957 | 4,200 |
| WINOOSKI RIVER | Vermont | Scour Critical — Countermeasures Installed | Fair | 1902 | 4,200 |
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.