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 |
|---|---|---|---|---|---|
| ROCKAWAY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1936 | 6,133 |
| SALMON FALLS RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Poor | 1950 | 6,132 |
| RODDY BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Good | 2007 | 6,131 |
| E BR RED CEDAR RIV DRN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1983 | 6,131 |
| PERRY CREEK | Iowa | Scour Critical — Countermeasures Installed | Fair | 1978 | 6,129 |
| JOHNS RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1952 | 6,124 |
| LITTLE SUGAR CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1956 | 6,122 |
| WEST BR. OF NAAMAN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1974 | 6,120 |
| RIFLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1937 | 6,120 |
| CLOVER CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1974 | 6,118 |
| KINNICKINNIC RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1953 | 6,113 |
| BEAVER BROOK | New Hampshire | Scour Critical — Countermeasures Installed | Poor | 1900 | 6,111 |
| FOX RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1971 | 6,100 |
| CIDRA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1973 | 6,100 |
| WHITE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1928 | 6,100 |
| PEACE RIVER | Florida | Scour Critical — Countermeasures Installed | Good | 1956 | 6,100 |
| PEACE RIVER OVERFLOW | Florida | Scour Critical — Countermeasures Installed | Fair | 1956 | 6,100 |
| W RIVER RD; MISS RIV | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1923 | 6,100 |
| CLAY HOLE CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1932 | 6,100 |
| ROSE CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1932 | 6,100 |
| NEDS BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1958 | 6,100 |
| LITTLE CHICO CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1982 | 6,096 |
| BRANCH TACONY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1938 | 6,088 |
| YAKIMA RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1971 | 6,083 |
| South Fork Quartz Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1938 | 6,082 |
| North Fork Quartz Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1939 | 6,082 |
| WATER MILL RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1926 | 6,078 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1960 | 6,075 |
| PORTAGE BYU | Missouri | Scour Critical — Countermeasures Installed | Fair | 1928 | 6,067 |
| HERON BAY | Alabama | Scour Critical — Countermeasures Installed | Fair | 1981 | 6,065 |
| JAMES BRANCH | Delaware | Scour Critical — Countermeasures Installed | Fair | 1920 | 6,064 |
| SAUK RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1929 | 6,063 |
| ARKANSAS RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1977 | 6,053 |
| SPROGELS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1990 | 6,050 |
| SALADO CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1937 | 6,045 |
| Columbia River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 6,042 |
| ELK CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1967 | 6,041 |
| BAD RV | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1956 | 6,040 |
| S FORK WILDCAT CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1994 | 6,040 |
| CACOOSING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1927 | 6,035 |
| MISSISSIPPI RIVER; ST | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1971 | 6,033 |
| TRIB TO BEAVER CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 6,025 |
| TRIBUTARY MIDDLE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 6,025 |
| FOX BRANCH | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1968 | 6,010 |
| ST MARYS RIVER OVERFLOW | Indiana | Scour Critical — Countermeasures Installed | Fair | 1996 | 6,001 |
| MAD RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1906 | 6,000 |
| BLACK CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1967 | 6,000 |
| VIVI RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1947 | 6,000 |
| JOES CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1981 | 6,000 |
| WARES CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1963 | 6,000 |
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.