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 |
|---|---|---|---|---|---|
| CRANE CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1922 | 10,100 |
| ST MARYS RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1981 | 10,100 |
| ST MARYS RIVER | Indiana | Scour Critical — Countermeasures Installed | Poor | 1981 | 10,100 |
| WATER CHARLES RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1922 | 10,100 |
| South Yamhill River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1956 | 10,099 |
| N. FK. FORKED DEER RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1963 | 10,097 |
| BABCOCK CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1941 | 10,090 |
| CABIN RUN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1950 | 10,089 |
| GINHOUSE CREEK | Florida | Scour Critical — Countermeasures Installed | Poor | 1965 | 10,081 |
| RED CLAY CREEK | Delaware | Scour Critical — Countermeasures Installed | Fair | 1931 | 10,072 |
| WILLIS BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1982 | 10,070 |
| PARKERS CREEK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1906 | 10,066 |
| HOUK DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1988 | 10,057 |
| WEST FORK BIG WALNUT CR | Indiana | Scour Critical — Countermeasures Installed | Fair | 1963 | 10,041 |
| WEST FORK BIG WALNUT CR | Indiana | Scour Critical — Countermeasures Installed | Fair | 1963 | 10,041 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1959 | 10,030 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1959 | 10,030 |
| OVER MAHONING CR. | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 10,026 |
| SLOAT BROOK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 10,020 |
| APPLE TREE COVE | Washington | Scour Critical — Countermeasures Installed | Fair | 1986 | 10,000 |
| Ten Mile Creek | Texas | Scour Critical — Countermeasures Installed | Fair | 1988 | 10,000 |
| MISSISSINEWA RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1950 | 10,000 |
| GUAYNABO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1954 | 10,000 |
| PAHEEHEE STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1950 | 10,000 |
| HANAWI STRM | Hawaii | Scour Critical — Countermeasures Installed | Good | 1968 | 10,000 |
| LOVILLS CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1977 | 10,000 |
| KALAOA STRM | Hawaii | Scour Critical — Countermeasures Installed | Good | 1967 | 10,000 |
| S.FK.TETON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1980 | 10,000 |
| S.FK.TETON RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1980 | 10,000 |
| Pennypack Creek | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1907 | 10,000 |
| BLACKSTONE RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1910 | 9,999 |
| BRADFIELD CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1973 | 9,995 |
| LODAL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1947 | 9,993 |
| SADDLE RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1902 | 9,984 |
| ASHLAND CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1911 | 9,979 |
| FARMERS HIGHLINE CANAL | Colorado | Scour Critical — Countermeasures Installed | Fair | 1971 | 9,958 |
| WATER PASKAMANSETT RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1826 | 9,957 |
| LITTLE PEE DEE SWP-1 | South Carolina | Scour Critical — Countermeasures Installed | Good | 1974 | 9,950 |
| LITTLE PEE DEE SWP-5 | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,950 |
| LITTLE PEE DEE SWP-5 | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1931 | 9,950 |
| LITTLE PEE DEE SWP-4 | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1931 | 9,950 |
| SOUTH BRUNSWICK RIVER | Georgia | Scour Critical — Countermeasures Installed | Fair | 1965 | 9,950 |
| LITTLE PEE DEE SWP-4 | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1974 | 9,950 |
| LITTLE PEE DEE SWP-2 | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1931 | 9,950 |
| LITTLE PEE DEE SWP-1 | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1931 | 9,950 |
| LITTLE PEE DEE SWP-2 | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,950 |
| CROWS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1979 | 9,942 |
| NFK DBL MTN FK BRAZOS RI | Texas | Scour Critical — Countermeasures Installed | Fair | 1953 | 9,942 |
| HEART RIVER | North Dakota | Scour Critical — Countermeasures Installed | Fair | 1931 | 9,940 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Installed | Fair | 1979 | 9,939 |
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.