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 |
|---|---|---|---|---|---|
| SILVER CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1986 | 8,166 |
| HARDY MILL CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1971 | 8,160 |
| WAWAYANDA CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1883 | 8,153 |
| RED WASH | California | Scour Critical — Countermeasures Installed | Good | 1967 | 8,150 |
| RED WASH | California | Scour Critical — Countermeasures Installed | Good | 1967 | 8,150 |
| Deep Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1948 | 8,140 |
| AU SABLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1960 | 8,126 |
| AU SABLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1960 | 8,125 |
| SANDY RIVER | Maine | Scour Critical — Countermeasures Installed | Fair | 1958 | 8,124 |
| LAFOURCHE BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 8,110 |
| STEEP BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1955 | 8,105 |
| CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 8,105 |
| CHENIERE CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 8,105 |
| KETTLE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1925 | 8,101 |
| ANIMAS RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1957 | 8,100 |
| HOLLY DRAIN | Michigan | Scour Critical — Countermeasures Installed | Good | 1961 | 8,100 |
| CAR SEAT CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1924 | 8,100 |
| STREAM | Nebraska | Scour Critical — Countermeasures Installed | Good | 1991 | 8,100 |
| NEW PASS | Florida | Scour Critical — Countermeasures Installed | Fair | 1965 | 8,100 |
| TAR RIVER | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1982 | 8,100 |
| Bear Creek | Florida | Scour Critical — Countermeasures Installed | Good | 1987 | 8,100 |
| Colorado River | Colorado | Scour Critical — Countermeasures Installed | Fair | 1977 | 8,096 |
| MT SCOTT CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 2001 | 8,094 |
| DRY FRIO RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1931 | 8,093 |
| FRIO RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1931 | 8,093 |
| LONG TOM RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1988 | 8,068 |
| DEER CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 8,066 |
| FRANKS BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1956 | 8,054 |
| BRADDOCK CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1924 | 8,050 |
| ANDERSON CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1927 | 8,038 |
| TURKEY CK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1972 | 8,030 |
| TURKEY CK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1982 | 8,030 |
| GRAND RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1975 | 8,009 |
| CHERRY RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 8,009 |
| MANANTICO CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1929 | 8,007 |
| PORTNEUF RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1963 | 8,000 |
| MARK WEST CREEK | California | Scour Critical — Countermeasures Installed | Poor | 1958 | 8,000 |
| HUNT RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1964 | 8,000 |
| GUANAJIBO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1978 | 8,000 |
| SOOS CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1927 | 8,000 |
| PORTNEUF RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1963 | 8,000 |
| LITTLE BLACK CREEK | Mississippi | Scour Critical — Countermeasures Installed | Good | 1961 | 8,000 |
| MEADOWBROOK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1963 | 8,000 |
| LITTLE BLACK CREEK | Mississippi | Scour Critical — Countermeasures Installed | Good | 1961 | 8,000 |
| INDIAN CREEK | Idaho | Scour Critical — Countermeasures Installed | Good | 1978 | 8,000 |
| PINEY CREEK | Tennessee | Scour Critical — Countermeasures Installed | Poor | 1956 | 7,993 |
| JACKSONBURG CREEK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1931 | 7,984 |
| PAWTUXET RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1956 | 7,979 |
| ELM FORK TRINITY RIVER | Texas | Scour Critical — Countermeasures Installed | Good | 1990 | 7,965 |
| AMMONOOSUC RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Good | 1950 | 7,962 |
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.