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 |
|---|---|---|---|---|---|
| PAWCATUCK RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1930 | 6,243 |
| W FORK GOOSE CRK | Texas | Scour Critical — Countermeasures Installed | Fair | 1991 | 6,242 |
| MILL BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1970 | 6,236 |
| HILLS BRANCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1990 | 6,236 |
| FERGUSON CREEK FERGUSON | New York | Scour Critical — Countermeasures Installed | Poor | 1965 | 6,235 |
| USRS CANAL | Oregon | Scour Critical — Countermeasures Installed | Fair | 1949 | 6,228 |
| WANITY SLOUGH | Washington | Scour Critical — Countermeasures Installed | Poor | 1964 | 6,219 |
| WANITY SLOUGH | Washington | Scour Critical — Countermeasures Installed | Good | 1948 | 6,219 |
| SPRING GARDEN BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1928 | 6,219 |
| EAST FORK HONEY CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1994 | 6,216 |
| FISHING RVR | Missouri | Scour Critical — Countermeasures Installed | Good | 1980 | 6,212 |
| COLUMBIA RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1962 | 6,212 |
| BENTLE BRANCH | Texas | Scour Critical — Countermeasures Installed | Fair | 1950 | 6,208 |
| 102 RVR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1985 | 6,207 |
| WATER VINE BROOK | Massachusetts | Scour Critical — Countermeasures Installed | Good | 1998 | 6,207 |
| FRANK & POET DRAIN | Michigan | Scour Critical — Countermeasures Installed | Poor | 1932 | 6,206 |
| POWDER RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1972 | 6,205 |
| POWDER RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1972 | 6,205 |
| Hurricane Creek Relief | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1948 | 6,200 |
| CACHE CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1955 | 6,200 |
| COLONELS FORK CREEK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1974 | 6,200 |
| GUNNISON RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1957 | 6,200 |
| CANEY BRANCH | Florida | Scour Critical — Countermeasures Installed | Fair | 1966 | 6,200 |
| CANCEL CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1920 | 6,200 |
| TRIB.SWATARA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 6,200 |
| Hubbard Creek | Arkansas | Scour Critical — Countermeasures Installed | Poor | 1948 | 6,200 |
| COTTONWOOD RIVER | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1983 | 6,200 |
| LITTLE KANAWHA RIVER | West Virginia | Scour Critical — Countermeasures Installed | Poor | 1929 | 6,200 |
| INDIAN MEADOW BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1940 | 6,200 |
| MOSHASSUCK RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1887 | 6,200 |
| Chatlin Lake Canal | Louisiana | Scour Critical — Countermeasures Installed | Good | 2006 | 6,200 |
| DENISON BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1934 | 6,200 |
| OLALLA CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1949 | 6,199 |
| MUSSER RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1935 | 6,199 |
| LOPATCONG CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1928 | 6,194 |
| CLATSKANIE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1934 | 6,189 |
| FLOODWAY DITCH | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 6,188 |
| FLOODWAY DITCH | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 6,188 |
| HARBOR BROOK | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1871 | 6,186 |
| BIG DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1958 | 6,182 |
| MORRIS & CUMMINGS CUT | Texas | Scour Critical — Countermeasures Installed | Fair | 1994 | 6,181 |
| HONEY CR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1972 | 6,177 |
| ROUGE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1952 | 6,175 |
| PRICKLY PEAR CREEK | Montana | Scour Critical — Countermeasures Installed | Fair | 1941 | 6,170 |
| WEST BR. RED CLAY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1940 | 6,163 |
| TR.EVITTS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1964 | 6,158 |
| San Pedro River | Arizona | Scour Critical — Countermeasures Installed | Poor | 1960 | 6,156 |
| MORRIS MILL POND | Delaware | Scour Critical — Countermeasures Installed | Fair | 1932 | 6,149 |
| DOWAGIAC RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1952 | 6,146 |
| PEQUEST RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1922 | 6,145 |
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.