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 |
|---|---|---|---|---|---|
| SMITH BROOK | Vermont | Scour Critical — Countermeasures Installed | Fair | 1945 | 5,700 |
| ARENAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1905 | 5,700 |
| TRAVERS CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1936 | 5,700 |
| WILLIAMS RIVER | Vermont | Scour Critical — Countermeasures Installed | Good | 1962 | 5,700 |
| ROGERS POND | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1941 | 5,700 |
| PATTEE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1939 | 5,700 |
| TURTLE CREEK | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1957 | 5,698 |
| ROCK RIVER | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1965 | 5,696 |
| ROCK RIVER | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1965 | 5,696 |
| A2 CHANNEL | Oregon | Scour Critical — Countermeasures Installed | Good | 1993 | 5,694 |
| CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1998 | 5,692 |
| SHEPARD BROOK & RR TRAIL | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1991 | 5,690 |
| GREEN BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1929 | 5,689 |
| PROVIDENCE RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1994 | 5,684 |
| LITTLE BUTTE CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 2005 | 5,681 |
| SATILLA RIVER | Georgia | Scour Critical — Countermeasures Installed | Good | 1964 | 5,680 |
| SMACKOVER CREEK | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1974 | 5,679 |
| SHINNECOCK BAY | New York | Scour Critical — Countermeasures Installed | Fair | 1988 | 5,676 |
| SPRING CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1926 | 5,674 |
| E Branch Brawley Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1957 | 5,668 |
| FANNO CREEK | Oregon | Scour Critical — Countermeasures Installed | Poor | 1958 | 5,667 |
| Devils Lake Fk Wilson R | Oregon | Scour Critical — Countermeasures Installed | Fair | 1940 | 5,662 |
| SQUIRES CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1982 | 5,661 |
| SEELYE BROOK | Minnesota | Scour Critical — Countermeasures Installed | Poor | 1984 | 5,661 |
| CAMPBELL CREEK SB RAMP | Alaska | Scour Critical — Countermeasures Installed | Good | 1981 | 5,660 |
| TRIB. TO COON CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1962 | 5,660 |
| BEAR CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1977 | 5,659 |
| SPRING CREEK | Tennessee | Scour Critical — Countermeasures Installed | Poor | 1930 | 5,658 |
| KANSAS RIVER & RAILROAD | Kansas | Scour Critical — Countermeasures Installed | Good | 1970 | 5,657 |
| HAZEN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1978 | 5,656 |
| Outfall Canal | Louisiana | Scour Critical — Countermeasures Installed | Good | 2010 | 5,650 |
| Fallout Canal | Louisiana | Scour Critical — Countermeasures Installed | Good | 2010 | 5,650 |
| SHORT CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1986 | 5,648 |
| SHIAWASSEE RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1928 | 5,647 |
| SPAULDING DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1940 | 5,643 |
| SPAULDING DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1949 | 5,643 |
| TRIB.MILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1925 | 5,642 |
| MUD CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1985 | 5,641 |
| SAW KILL | New York | Scour Critical — Countermeasures Installed | Poor | 1929 | 5,635 |
| SEVILLE SUMNER DRAIN | Michigan | Scour Critical — Countermeasures Installed | Poor | 1936 | 5,634 |
| N BRANCH BLACK RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1992 | 5,632 |
| CYPRESS CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1981 | 5,631 |
| LITTLE WALNUT RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1970 | 5,627 |
| BR.ASSISCUNK CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1925 | 5,626 |
| OVERFLOW | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1950 | 5,624 |
| BIG SANDY RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1950 | 5,624 |
| OVERFLOW | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1950 | 5,624 |
| OVERFLOW | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1950 | 5,624 |
| WHITEWATER RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1935 | 5,622 |
| IRON ORE CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1955 | 5,622 |
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.