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 |
|---|---|---|---|---|---|
| SPARKILL CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1906 | 22,073 |
| Intracoastal Waterway | Florida | Scour Critical — Countermeasures Installed | Fair | 1979 | 22,000 |
| W. LITTLE LLAGAS CREEK | California | Scour Critical — Countermeasures Installed | Good | 1965 | 22,000 |
| BOISE RIVER;N. CHANNEL | Idaho | Scour Critical — Countermeasures Installed | Good | 1992 | 22,000 |
| ANCLOTE RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1972 | 22,000 |
| FOUNTAIN CREEK | Colorado | Scour Critical — Countermeasures Installed | Poor | 1965 | 22,000 |
| W FRK E BR WHITE CLAY CR | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1965 | 21,979 |
| E.FRK BR. WHITE CLAY CR | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1965 | 21,979 |
| TURKEY CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1939 | 21,969 |
| SWIFTWATER CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1957 | 21,965 |
| SCOT RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1948 | 21,965 |
| MCAIN CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1993 | 21,933 |
| THIRD RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1954 | 21,931 |
| PASSAIC RIVER | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1908 | 21,920 |
| TRIB TO LITTLE MILL CRK | Delaware | Scour Critical — Countermeasures Installed | Good | 1949 | 21,909 |
| FIVE MILE RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1850 | 21,900 |
| MARSHALLS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1930 | 21,886 |
| WOODBURY CREEK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1892 | 21,874 |
| SAGINAW RV;MARTIN ST&RR | Michigan | Scour Critical — Countermeasures Installed | Fair | 1976 | 21,832 |
| COWLITZ RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1953 | 21,828 |
| COWLITZ RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1953 | 21,828 |
| DOAN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 21,800 |
| DOAN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 21,800 |
| LEHIGH RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1912 | 21,778 |
| CSX RR & UNNAMED CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1949 | 21,772 |
| CSX RR & UNNAMED CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1958 | 21,772 |
| PRINGLE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1928 | 21,752 |
| PONCHATOULA CR. | Louisiana | Scour Critical — Countermeasures Installed | Good | 1960 | 21,736 |
| COMB AMTRAK & CONN RIV | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1922 | 21,706 |
| JESSE LITTLE DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1964 | 21,697 |
| BROWN DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1964 | 21,697 |
| Calapooia Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 21,606 |
| Sodom Ditch Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1959 | 21,606 |
| Courtney Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1959 | 21,606 |
| Sodom Ditch Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1959 | 21,606 |
| Courtney Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1959 | 21,606 |
| Calapooia Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 21,606 |
| Sodom Ditch Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 21,606 |
| Courtney Creek Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1959 | 21,606 |
| Sodom Ditch Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 21,606 |
| Calapooia Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 21,606 |
| Courtney Creek Oflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1959 | 21,606 |
| Calapooia Oflow | Oregon | Scour Critical — Countermeasures Installed | Good | 1958 | 21,606 |
| MILL BRANCH | Texas | Scour Critical — Countermeasures Installed | Fair | 1986 | 21,577 |
| BUFFALO CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 21,561 |
| CURLEW CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1986 | 21,500 |
| Intracoastal Waterway | Florida | Scour Critical — Countermeasures Installed | Fair | 1956 | 21,500 |
| WATER CHARLES RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1967 | 21,500 |
| CEDAR CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1923 | 21,480 |
| WYNOOCHEE RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1935 | 21,466 |
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.