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 |
|---|---|---|---|---|---|
| REYNOLDS CHANNEL | New York | Scour Critical — Countermeasures Installed | Fair | 1953 | 5,026 |
| L NATALBANY RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 5,026 |
| REYNOLDS CHANNEL | New York | Scour Critical — Countermeasures Installed | Fair | 1953 | 5,026 |
| NAT. RIVER RELIEF | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1963 | 5,026 |
| MUNCIE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1973 | 5,026 |
| OVER MORGAN RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1950 | 5,026 |
| HOLDER CR | Washington | Scour Critical — Countermeasures Installed | Fair | 1960 | 5,021 |
| YELLOWSTONE RIVER | Montana | Scour Critical — Countermeasures Installed | Poor | 1957 | 5,017 |
| MILL CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1973 | 5,013 |
| CAYUGA CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1954 | 5,008 |
| CICERO CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1986 | 5,008 |
| LOST RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1941 | 5,002 |
| RED ROCK WASH | Nevada | Scour Critical — Countermeasures Installed | Good | 1985 | 5,000 |
| CHANNEL | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1910 | 5,000 |
| ROARING BR WALLOOMSAC BK | Vermont | Scour Critical — Countermeasures Installed | Fair | 1939 | 5,000 |
| SONOMA CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1956 | 5,000 |
| MILE BRANCH | Florida | Scour Critical — Countermeasures Installed | Good | 1965 | 5,000 |
| FURNACE BROOK | Vermont | Scour Critical — Countermeasures Installed | Fair | 1960 | 5,000 |
| BARRANQUITAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1911 | 5,000 |
| DIRTY CAMP RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1900 | 5,000 |
| CREEK | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1941 | 5,000 |
| CHIPPEWA RIVER | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1955 | 5,000 |
| WILDCAT CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1960 | 5,000 |
| SOUTH FORK EEL RIVER | California | Scour Critical — Countermeasures Installed | Fair | 1962 | 5,000 |
| SYCAMORE RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1950 | 5,000 |
| GRANDE DE LOIZA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1950 | 5,000 |
| NORTH BRANCH ROUGE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1943 | 5,000 |
| BEAR CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1963 | 5,000 |
| SANTA MARIA RIVER | California | Scour Critical — Countermeasures Installed | Poor | 1955 | 5,000 |
| BEAR CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1963 | 5,000 |
| S FK WILLIS CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1941 | 5,000 |
| E FORK LICK CREEK | Illinois | Scour Critical — Countermeasures Installed | Poor | 1962 | 5,000 |
| PERKINS CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1971 | 5,000 |
| TRIB TO 18 MILE CR | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1958 | 5,000 |
| ST JOSEPH RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1984 | 5,000 |
| KINGS CREEK | California | Scour Critical — Countermeasures Installed | Poor | 1927 | 5,000 |
| EAST ZAYANTE ROAD | California | Scour Critical — Countermeasures Installed | Fair | 1930 | 5,000 |
| WHITEWATER RIVER | California | Scour Critical — Countermeasures Installed | Fair | 1951 | 5,000 |
| SCOTT CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1973 | 5,000 |
| HUNTSVILLE SPRING BRANCH | Alabama | Scour Critical — Countermeasures Installed | Fair | 1996 | 5,000 |
| DRY CREEK CANAL | California | Scour Critical — Countermeasures Installed | Fair | 1941 | 5,000 |
| HYALITE CREEK | Montana | Scour Critical — Countermeasures Installed | Good | 2022 | 4,997 |
| POMPONAUGH CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,992 |
| DEVILS FORD CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1964 | 4,992 |
| CHEYENNE CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1959 | 4,986 |
| MOUNTAIN CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1954 | 4,984 |
| BEAVER BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1967 | 4,983 |
| EAST BRANCH SAUCON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1956 | 4,977 |
| W. BR. BRANDYWINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1935 | 4,970 |
| YELLOWSTONE RIVER | Montana | Scour Critical — Countermeasures Installed | Fair | 1930 | 4,964 |
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.