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 |
|---|---|---|---|---|---|
| DRAW | Texas | Scour Critical — Countermeasures Installed | Fair | 1960 | 4,098 |
| THREAD RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1928 | 4,097 |
| SPRING RIVER | Kansas | Scour Critical — Countermeasures Installed | Good | 1964 | 4,096 |
| WEST KEMPF CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1979 | 4,093 |
| Dry Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1933 | 4,083 |
| BIG INDIAN CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1971 | 4,080 |
| COULEE | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1972 | 4,080 |
| DRIFTWOOD RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1959 | 4,080 |
| TRIB TO ROCKAWAY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1900 | 4,079 |
| LOCAL DRAINAGE | Colorado | Scour Critical — Countermeasures Installed | Good | 2018 | 4,074 |
| TICKFAW RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 4,071 |
| Dry Creek | Alabama | Scour Critical — Countermeasures Installed | Fair | 1940 | 4,070 |
| REEVES DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1996 | 4,070 |
| SKUNK CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1986 | 4,068 |
| N FK NOOKSACK RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1954 | 4,066 |
| TRIB NO BR MAHANTANGO CR | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 4,066 |
| THOMAS CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1961 | 4,066 |
| BULL CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,065 |
| BULL CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,065 |
| TUTUILLA CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1988 | 4,062 |
| NO CR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1977 | 4,053 |
| CANEY BAYOU REL | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1957 | 4,051 |
| SHEBOYGAN RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1957 | 4,050 |
| LITTLE PORTAGE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1929 | 4,050 |
| HUNLOCK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1925 | 4,044 |
| CHEHALIS RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1958 | 4,044 |
| N BR BERMUDIAN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 4,044 |
| DARBY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1922 | 4,029 |
| I-465 WB LICK CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 4,028 |
| SOL DUC RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1958 | 4,018 |
| BULL CREEK BNSF RR | Kansas | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,016 |
| REDWOOD CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1976 | 4,014 |
| REDWOOD CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1976 | 4,014 |
| SILVER CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1937 | 4,014 |
| KUSSHI CR | Washington | Scour Critical — Countermeasures Installed | Poor | 1945 | 4,013 |
| CEDAR CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1958 | 4,008 |
| Marys River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1949 | 4,008 |
| CHELATCHIE CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1953 | 4,008 |
| YELLOWSTONE RIVER 170 | Montana | Scour Critical — Countermeasures Installed | Poor | 1949 | 4,005 |
| FOUNTAIN CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,005 |
| INDIAN CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1959 | 4,000 |
| DRY CREEK CANAL | California | Scour Critical — Countermeasures Installed | Fair | 1941 | 4,000 |
| JUAN MARTIN RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1916 | 4,000 |
| FURNACE BROOK | New York | Scour Critical — Countermeasures Installed | Fair | 1948 | 4,000 |
| W BRANCH SAUGATUCK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1957 | 4,000 |
| FOWLER SWITCH CANAL | California | Scour Critical — Countermeasures Installed | Fair | 1912 | 4,000 |
| SPRING CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1989 | 4,000 |
| Hogskin Lake Creek | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1989 | 4,000 |
| WILLAMETTE R COAST FK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1967 | 4,000 |
| MANCOS RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1959 | 4,000 |
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.