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 |
|---|---|---|---|---|---|
| DUCK CRK | Nevada | Scour Critical — Countermeasures Installed | Good | 1974 | 12,000 |
| DUCK CRK | Nevada | Scour Critical — Countermeasures Installed | Good | 1974 | 12,000 |
| CULEBRINAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1979 | 12,000 |
| TAYLORS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1956 | 11,986 |
| DIVERSION CANAL | Louisiana | Scour Critical — Countermeasures Installed | Good | 1989 | 11,969 |
| BURNT RIVER(DIXIE CR) | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 11,968 |
| KEARSLEY CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 11,960 |
| CLEAR FORK TRINITY RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1951 | 11,958 |
| BURNT RIVER (RR TUNNEL) | Oregon | Scour Critical — Countermeasures Installed | Good | 1971 | 11,958 |
| CLEAR FORK TRINITY RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1936 | 11,958 |
| HAYES CREEK | Michigan | Scour Critical — Countermeasures Installed | Good | 1993 | 11,950 |
| EAST BRANCH SNEECH BROOK | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1926 | 11,938 |
| NODAWAY RVR | Missouri | Scour Critical — Countermeasures Installed | Poor | 1953 | 11,937 |
| NORTH CR & GILLMAN TRAIL | Washington | Scour Critical — Countermeasures Installed | Good | 1968 | 11,919 |
| N. BRANCH RANCOCAS CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1957 | 11,915 |
| LACKAWANNA RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1958 | 11,900 |
| CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1945 | 11,900 |
| BARRANQUITAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1908 | 11,900 |
| THORNAPPLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1930 | 11,887 |
| COPLAY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1910 | 11,880 |
| JACKSON BRANCH | Texas | Scour Critical — Countermeasures Installed | Fair | 1993 | 11,871 |
| CYPRESS CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1991 | 11,869 |
| Bledsoe Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 11,858 |
| East Fork Dairy Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 11,858 |
| HAYWORTH COUNTY DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1988 | 11,851 |
| HAYWORTH COUNTY DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1957 | 11,851 |
| PRINCETON CANAL C-102 | Florida | Scour Critical — Countermeasures Installed | Good | 1965 | 11,850 |
| HERSEY CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1985 | 11,841 |
| HERSEY CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1985 | 11,841 |
| MILL CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1960 | 11,840 |
| MILL CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1960 | 11,840 |
| THIRD RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1963 | 11,837 |
| MOREAU RVR OVERFLO | Missouri | Scour Critical — Countermeasures Installed | Fair | 1967 | 11,836 |
| MOREAU RVR | Missouri | Scour Critical — Countermeasures Installed | Poor | 1967 | 11,836 |
| HEMLOCK BROOK | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1926 | 11,806 |
| STONEY BROOK | Connecticut | Scour Critical — Countermeasures Installed | Good | 1986 | 11,800 |
| UP POAMOHO STRM-BRODIE 2 | Hawaii | Scour Critical — Countermeasures Installed | Good | 1937 | 11,800 |
| EIGHT MILE BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1934 | 11,800 |
| SAW MILL BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1951 | 11,800 |
| Marys River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1933 | 11,781 |
| DRY CREEK | California | Scour Critical — Countermeasures Installed | Good | 1959 | 11,776 |
| GROVE CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1928 | 11,770 |
| PASSAIC RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1900 | 11,766 |
| MCCOY WASH | California | Scour Critical — Countermeasures Installed | Fair | 1969 | 11,750 |
| GALE DITCH | California | Scour Critical — Countermeasures Installed | Fair | 1969 | 11,750 |
| MCCOY WASH | California | Scour Critical — Countermeasures Installed | Fair | 1969 | 11,750 |
| PALOWALLA DITCH | California | Scour Critical — Countermeasures Installed | Good | 1969 | 11,750 |
| PALOWALLA DITCH | California | Scour Critical — Countermeasures Installed | Good | 1969 | 11,750 |
| ARKANSAS RIVER DRAINAGE | Kansas | Scour Critical — Countermeasures Installed | Good | 1967 | 11,739 |
| CLINTON RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1960 | 11,736 |
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.