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 |
|---|---|---|---|---|---|
| SLOUGH | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1976 | 2,958 |
| W BR WAISKA RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1975 | 2,956 |
| LITTLE NESHAMINY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 2,952 |
| LITTLE MULBERRYCREEKREIL | Alabama | Scour Critical — Countermeasures Installed | Fair | 1939 | 2,950 |
| GUAYNABO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1983 | 2,950 |
| HILLS. BAY & BAYSHORE B. | Florida | Scour Critical — Countermeasures Installed | Fair | 1927 | 2,950 |
| CHAMPION CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1942 | 2,947 |
| ROGUE RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1963 | 2,946 |
| ELDER RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1952 | 2,942 |
| Dry Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1932 | 2,940 |
| Palmer Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1984 | 2,939 |
| SWAMP BROOK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1958 | 2,932 |
| SARDINE CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1938 | 2,931 |
| BUCKHEAD CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1988 | 2,930 |
| HAZLE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1961 | 2,928 |
| PINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1915 | 2,927 |
| SANDY BOIS DARC | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1930 | 2,927 |
| S FK SCAPPOOSE CREEK | Oregon | Scour Critical — Countermeasures Installed | Poor | 1957 | 2,926 |
| Mid. Fk. Coquille River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 2,925 |
| SANDY CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1979 | 2,925 |
| COQUILLE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,925 |
| COQUILLE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,925 |
| NORTH COTTONWOOD RIVER | Kansas | Scour Critical — Countermeasures Installed | Good | 1987 | 2,923 |
| Tenmile Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1931 | 2,922 |
| CASS RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1966 | 2,920 |
| PINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1929 | 2,917 |
| CHERRY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 2,917 |
| EAST BRANCH RED CLAY CR. | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1923 | 2,912 |
| Climas Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1984 | 2,912 |
| LYNN CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 2,910 |
| BEAVER MEADOW CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1955 | 2,910 |
| Willow Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,909 |
| OVER INLET CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1934 | 2,904 |
| Stockton Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1938 | 2,901 |
| JOHNSON CREEK | Oregon | Scour Critical — Countermeasures Installed | Poor | 1930 | 2,901 |
| DEEP CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1958 | 2,901 |
| HAY CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1930 | 2,901 |
| DEEP CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1965 | 2,900 |
| HINTON CREEK | North Carolina | Scour Critical — Countermeasures Installed | Poor | 1955 | 2,900 |
| CAMP CREEK CANAL | Mississippi | Scour Critical — Countermeasures Installed | Good | 1992 | 2,900 |
| NORTH FORK CATAWBA RIVER | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1938 | 2,900 |
| BIG CEDAR RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1952 | 2,900 |
| MASHEL RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1937 | 2,900 |
| ROARING CREEK | West Virginia | Scour Critical — Countermeasures Installed | Poor | 1919 | 2,900 |
| DAN RIVER | North Carolina | Scour Critical — Countermeasures Installed | Poor | 1955 | 2,900 |
| BEAVERDAM CREEK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1987 | 2,900 |
| MILL RIVER | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1940 | 2,900 |
| CARSON RVR | Nevada | Scour Critical — Countermeasures Installed | Fair | 1987 | 2,900 |
| FAIRFOREST CREEK | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1987 | 2,900 |
| KENAI RIVER (SCHOONERS) | Alaska | Scour Critical — Countermeasures Installed | Fair | 1954 | 2,900 |
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.