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 |
|---|---|---|---|---|---|
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Installed | Fair | 1979 | 9,939 |
| SO. BRANCH RUSSIA BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1951 | 9,929 |
| WASHOUGAL RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1947 | 9,924 |
| STONY CREEK / 3255-J5 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1933 | 9,921 |
| DUNCAN CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Poor | 1949 | 9,920 |
| N. Branch of Canoe Brook | New Jersey | Scour Critical — Countermeasures Installed | Good | 1956 | 9,908 |
| CANARY DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 2000 | 9,905 |
| NAUGATUCK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1958 | 9,900 |
| CLEMS BRANCH | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,900 |
| Sweetwater Creek | Florida | Scour Critical — Countermeasures Installed | Good | 1965 | 9,900 |
| CEDRO CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1953 | 9,900 |
| SPRING BROOK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1968 | 9,900 |
| BRANCH NESHAMINY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1936 | 9,883 |
| SPRINGERS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1929 | 9,860 |
| BRANCH OF PENNYPACK CRK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1958 | 9,860 |
| ROCKY SLOUGH | Nevada | Scour Critical — Countermeasures Installed | Good | 1957 | 9,850 |
| ELIZABETH RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1968 | 9,847 |
| ST MARYS RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1969 | 9,815 |
| POST OAK CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1930 | 9,804 |
| Slough | Oregon | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,803 |
| BEAVER CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1949 | 9,800 |
| SOUTH FORK CATAWBA RIVER | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1977 | 9,800 |
| MULLET RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Good | 1976 | 9,800 |
| TUCKASEGEE RIVER | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1969 | 9,800 |
| LITTLE TALLAPOOSA RIVER | Georgia | Scour Critical — Countermeasures Installed | Fair | 1971 | 9,800 |
| BURLINGTON BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1961 | 9,800 |
| UNNAMED CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1950 | 9,800 |
| WHITEWATER RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1955 | 9,799 |
| DRY CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1960 | 9,799 |
| WHITEWATER RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1957 | 9,799 |
| DRY CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1955 | 9,799 |
| FERDUN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1956 | 9,785 |
| BIG RVR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1977 | 9,781 |
| Illinios Bayou | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1964 | 9,777 |
| QUANTUCK CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1941 | 9,775 |
| E BR AU SABLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 9,772 |
| MOSHASSUCK RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1967 | 9,765 |
| SNAKE RIVER;KING HILL | Idaho | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,750 |
| RD;UPRR;SNAKE R;GLENNS F | Idaho | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,750 |
| SNAKE RIVER;KING HILL | Idaho | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,750 |
| RD;UPRR;SNAKE R;GLENNS F | Idaho | Scour Critical — Countermeasures Installed | Fair | 1974 | 9,750 |
| MID COLYELL CR. | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1932 | 9,745 |
| TR.LAUREL CK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 9,745 |
| MOREAU RVR | Missouri | Scour Critical — Countermeasures Installed | Poor | 1960 | 9,742 |
| SNOQUALMIE RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1931 | 9,740 |
| GALLATIN RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1965 | 9,726 |
| GALLATIN RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1965 | 9,726 |
| PUGET SOUND @ FAUNTLEROY | Washington | Scour Critical — Countermeasures Installed | Good | 1984 | 9,721 |
| PUGET SOUND @ FAUNTLEROY | Washington | Scour Critical — Countermeasures Installed | Fair | 1957 | 9,721 |
| BACK SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1931 | 9,700 |
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.