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 SANDY CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1955 | 3,092 |
| SANDY CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1979 | 3,092 |
| SASCO BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,090 |
| DUGDEMONA RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1976 | 3,086 |
| PEQUEST RIVER BRANCH | New Jersey | Scour Critical — Countermeasures Installed | Good | 1933 | 3,081 |
| BUFFALO CANAL | Florida | Scour Critical — Countermeasures Installed | Good | 1984 | 3,078 |
| MYER CREEK | Kentucky | Scour Critical — Countermeasures Installed | Poor | 1956 | 3,076 |
| WOLF CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1940 | 3,071 |
| RICE CREEK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,070 |
| LITTLE WALNUT RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1949 | 3,068 |
| NAUGATUCK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1956 | 3,067 |
| WHITE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,067 |
| MONTOYA DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Installed | Good | 1984 | 3,065 |
| PRAIRIE CREEK TRIB | Texas | Scour Critical — Countermeasures Installed | Fair | 1974 | 3,065 |
| BIG SUGAR CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1979 | 3,063 |
| WILLOW CREEK | Utah | Scour Critical — Countermeasures Installed | Fair | 1962 | 3,058 |
| LIME CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1946 | 3,056 |
| BLANCHARD DRAIN | Michigan | Scour Critical — Countermeasures Installed | Poor | 1948 | 3,056 |
| BRAIR FORK FLINT RIVER | Alabama | Scour Critical — Countermeasures Installed | Fair | 1949 | 3,052 |
| PUGET SOUND @ EAGLE HRBR | Washington | Scour Critical — Countermeasures Installed | Fair | 2006 | 3,052 |
| BEAVER RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1905 | 3,051 |
| BROWARD RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1968 | 3,051 |
| LITTLE McPHERSON BAYOU | Florida | Scour Critical — Countermeasures Installed | Fair | 1954 | 3,046 |
| N F BLK VERMILLION R DRN | Kansas | Scour Critical — Countermeasures Installed | Good | 1958 | 3,045 |
| ALGER CREEK | Michigan | Scour Critical — Countermeasures Installed | Poor | 1928 | 3,044 |
| NINE MILE CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,042 |
| BEAVER CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,042 |
| ELM RV | South Dakota | Scour Critical — Countermeasures Installed | Poor | 1959 | 3,041 |
| PISCATAQUA ESTUARY | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,041 |
| BEAVER CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,040 |
| PAINT RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,039 |
| LAUREL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1934 | 3,032 |
| SWAN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1926 | 3,030 |
| TROUT CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1933 | 3,029 |
| WEST SANDY CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1942 | 3,025 |
| MILL CREEK | New York | Scour Critical — Countermeasures Installed | Poor | 1939 | 3,022 |
| COAST FK WILLAMETTE R | Oregon | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,020 |
| LONG CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1964 | 3,017 |
| LABETTE CREEK DRAINAGE | Kansas | Scour Critical — Countermeasures Installed | Fair | 1959 | 3,016 |
| BACHELOR CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1959 | 3,016 |
| BUTTE CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,013 |
| EBENEEZER CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1963 | 3,010 |
| IRISH RUN CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1984 | 3,009 |
| YELLOW RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1994 | 3,008 |
| UNAMI CREEK / 2806-E4 | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1890 | 3,005 |
| RIO PUERCO OF THE WEST | New Mexico | Scour Critical — Countermeasures Installed | Good | 1980 | 3,004 |
| SHOVELSBURG RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1938 | 3,004 |
| Big Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1931 | 3,003 |
| RICKREALL CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1965 | 3,001 |
| S. EDISTO RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1953 | 3,000 |
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.