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 |
|---|---|---|---|---|---|
| PICKERING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1969 | 7,961 |
| MOSHASSUCK RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1916 | 7,957 |
| PERKIOMEN CREEK/2917-D9 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1967 | 7,957 |
| LONE ROCK CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1959 | 7,955 |
| PLATTE OVERFLOW | Nebraska | Scour Critical — Countermeasures Installed | Fair | 1955 | 7,955 |
| LONE ROCK CK | South Dakota | Scour Critical — Countermeasures Installed | Fair | 1959 | 7,955 |
| TRUCKEE RIVER | Nevada | Scour Critical — Countermeasures Installed | Fair | 1966 | 7,950 |
| TRUCKEE RIVER | Nevada | Scour Critical — Countermeasures Installed | Fair | 1966 | 7,950 |
| LITTLE GRAVOIS CR | Missouri | Scour Critical — Countermeasures Installed | Good | 1966 | 7,947 |
| FISHING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1910 | 7,944 |
| PLUM CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1956 | 7,943 |
| BOOTS CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1926 | 7,943 |
| HICKS CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1942 | 7,939 |
| RIDLEY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 7,934 |
| LITTLE GRAVOIS CR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1966 | 7,933 |
| FRENCH CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 7,931 |
| STEELE BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1963 | 7,900 |
| BEAR CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1970 | 7,900 |
| MANATAWNY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1951 | 7,884 |
| Ash Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1981 | 7,883 |
| SOUTH UMPQUA OVERFLOW | Oregon | Scour Critical — Countermeasures Installed | Good | 1963 | 7,879 |
| SLATE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1927 | 7,878 |
| BUTCHER KNIFE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1927 | 7,878 |
| SLATE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1927 | 7,878 |
| WATERS CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1927 | 7,878 |
| GRAND RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1979 | 7,875 |
| 3 MILE BRANCH | Illinois | Scour Critical — Countermeasures Installed | Fair | 1974 | 7,850 |
| WOONASQUATUCKET RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1979 | 7,850 |
| Plympton Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 7,845 |
| MATTAWOMAN CREEK | Maryland | Scour Critical — Countermeasures Installed | Fair | 1984 | 7,843 |
| LABETTE CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1937 | 7,842 |
| POST OAK CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1933 | 7,826 |
| TRIBUTARY TO SEVERN RUN | Maryland | Scour Critical — Countermeasures Installed | Fair | 1988 | 7,820 |
| WATER QUINEBAUG RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1938 | 7,817 |
| GRIFFIN CR | Washington | Scour Critical — Countermeasures Installed | Fair | 1945 | 7,813 |
| WILLOW CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1980 | 7,803 |
| BLACKSTONE RVR P&W BP | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 2021 | 7,800 |
| TACITO CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1991 | 7,800 |
| HURRICANE CREEK | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1950 | 7,800 |
| SALTO ABAJO CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1892 | 7,800 |
| CA¥ABONCITO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1989 | 7,800 |
| NAUGATUCK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1959 | 7,800 |
| CA¥ABONCITO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1930 | 7,800 |
| HAW RIVER & SO. RAILWAY | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1990 | 7,800 |
| CICERO CREEK (MORSE RES) | Indiana | Scour Critical — Countermeasures Installed | Fair | 1953 | 7,800 |
| GRAND RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1989 | 7,800 |
| GURABO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1980 | 7,800 |
| BRANDYWINE CREEK FLOOD | Pennsylvania | Scour Critical — Countermeasures Installed | Good | 1912 | 7,797 |
| BRANDYWINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1902 | 7,797 |
| ROCK CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1966 | 7,783 |
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.