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 |
|---|---|---|---|---|---|
| ROUGE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1987 | 8,706 |
| WENATCHEE RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1962 | 8,705 |
| WENATCHEE R | Washington | Scour Critical — Countermeasures Installed | Fair | 1962 | 8,705 |
| WENATCHEE RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1947 | 8,705 |
| WENATCHEE RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1929 | 8,705 |
| HO-HO-KUS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1900 | 8,704 |
| WOLF CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1979 | 8,701 |
| GRANDE DE LOIZA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1955 | 8,700 |
| LA PLATA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1951 | 8,700 |
| Little Creek | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1948 | 8,700 |
| TRIB TO MOUNTAIN CRK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1976 | 8,700 |
| JACKSON BRANCH | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1982 | 8,700 |
| MOUNTAIN CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1976 | 8,700 |
| TRIB TO MOUNTAIN CK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1976 | 8,700 |
| CULEBRA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1960 | 8,700 |
| WHITEWATER RIVER | California | Scour Critical — Countermeasures Installed | Poor | 1950 | 8,700 |
| NONEWAUG RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1928 | 8,700 |
| TRIB TO MOUNTAIN CK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1976 | 8,700 |
| SECOND BROAD RIVER | North Carolina | Scour Critical — Countermeasures Installed | Poor | 1921 | 8,700 |
| BAIROA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1981 | 8,700 |
| LITTLE SUGAR CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1964 | 8,700 |
| CHENIERE CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1970 | 8,694 |
| EAST BR.RED CLAY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1940 | 8,686 |
| PUKELE STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1928 | 8,680 |
| LITTLE DUCK CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1986 | 8,673 |
| TULPEHOCKEN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1949 | 8,670 |
| TOOKANY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1927 | 8,669 |
| WHETSTONE CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1953 | 8,668 |
| MILL CREEK | Oregon | Scour Critical — Countermeasures Installed | Poor | 1975 | 8,665 |
| WATER MILLERS RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1850 | 8,663 |
| HACKBERRY CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1947 | 8,662 |
| CHIPPEWA RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1961 | 8,658 |
| CHIPPEWA RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 8,658 |
| HOUGHS CREEK / 3039-B6 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1941 | 8,655 |
| SWAMP CREEK | Washington | Scour Critical — Countermeasures Installed | Poor | 1960 | 8,654 |
| MULBERRY CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1964 | 8,650 |
| MULBERRY CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1964 | 8,650 |
| NOROTON RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1950 | 8,650 |
| OVERPECK CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1951 | 8,625 |
| LONG BRANCH CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1986 | 8,621 |
| Shoal River | Florida | Scour Critical — Countermeasures Installed | Fair | 1930 | 8,600 |
| INGENIO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1918 | 8,600 |
| KELLY BROOK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1932 | 8,600 |
| GUANAJIBO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1978 | 8,600 |
| LITTLE BRANDYWINE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1921 | 8,593 |
| BRANDYWINE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1942 | 8,593 |
| ROCKAWAY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1900 | 8,583 |
| DOUGLAS CREEK | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1955 | 8,579 |
| KITTATINY BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1929 | 8,564 |
| RIO HONDO | New Mexico | Scour Critical — Countermeasures Installed | Fair | 1972 | 8,558 |
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.