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 |
|---|---|---|---|---|---|
| BR PINE R | Michigan | Scour Critical — Countermeasures Installed | Fair | 1947 | 3,850 |
| PINE RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1957 | 3,850 |
| GOFFLE BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1958 | 3,850 |
| APPLE CREEK | North Dakota | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,850 |
| HOUGHS CREEK / 3038-J5 | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1910 | 3,839 |
| DELAWARE CANAL/3151-F2 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1932 | 3,837 |
| MILLER CREEK | California | Scour Critical — Countermeasures Installed | Good | 1970 | 3,830 |
| RAYSTOWN BR.JUNIATA RIV. | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1934 | 3,829 |
| STONY BROOK | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1935 | 3,820 |
| SECOND COW CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1980 | 3,817 |
| BLACK CR OVERFLOW | New York | Scour Critical — Countermeasures Installed | Poor | 1927 | 3,816 |
| GRAND RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1924 | 3,815 |
| E FK WHITE RIVER OVFL | Indiana | Scour Critical — Countermeasures Installed | Fair | 1981 | 3,814 |
| MILLECOQUIN RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1940 | 3,813 |
| SANBORN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1934 | 3,813 |
| BALDWIN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1931 | 3,813 |
| BLACKSTONE RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1885 | 3,811 |
| MILL CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1951 | 3,810 |
| MILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1905 | 3,809 |
| EAST BR BRANDYWINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1950 | 3,807 |
| KASKASKIA ST MISSISSI | Missouri | Scour Critical — Countermeasures Installed | Poor | 1942 | 3,806 |
| HORSE ISLAND CHUTE | Missouri | Scour Critical — Countermeasures Installed | Poor | 1942 | 3,806 |
| LIMESTONE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1936 | 3,806 |
| LAKE CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1946 | 3,805 |
| GRANDE RONDE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1965 | 3,803 |
| MOLE CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Good | 2015 | 3,800 |
| GUAMANI RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1925 | 3,800 |
| GUAYANES RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1969 | 3,800 |
| FRENCH RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,800 |
| MARYS RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1953 | 3,800 |
| PUGET SOUND @ SEATTLE | Washington | Scour Critical — Countermeasures Installed | Fair | 1971 | 3,800 |
| BURCH CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1914 | 3,800 |
| BIG SANDY CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1971 | 3,800 |
| MUD CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1947 | 3,800 |
| PORTER SLOUGH | California | Scour Critical — Countermeasures Installed | Fair | 1930 | 3,800 |
| ISNER CREEK | West Virginia | Scour Critical — Countermeasures Installed | Poor | 1939 | 3,800 |
| BLACK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1930 | 3,799 |
| RATTLESNAKE CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1947 | 3,793 |
| OVER FRENCH CREEK E BR | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1925 | 3,791 |
| NORWALK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1928 | 3,790 |
| BIG BLUE RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1926 | 3,784 |
| BUTLER CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1992 | 3,783 |
| FALL CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1998 | 3,783 |
| ROGUE RIVER - DODGE BR | Oregon | Scour Critical — Countermeasures Installed | Fair | 1953 | 3,782 |
| PICOU BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,782 |
| BAYOU BARBARY | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,782 |
| TRIB TO CONEMAUGH RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1942 | 3,779 |
| FRENCH DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1934 | 3,777 |
| SWAN CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1916 | 3,776 |
| W BR BRANDYWINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1923 | 3,775 |
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.