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 |
|---|---|---|---|---|---|
| SCULLS CREEK | Georgia | Scour Critical — Countermeasures Installed | Fair | 2006 | 2,580 |
| LITTLE TIRED CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 2009 | 2,580 |
| BOOTS CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1976 | 2,580 |
| CABIN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1931 | 2,577 |
| ROCK CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1983 | 2,575 |
| M FORK WILDCAT CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1981 | 2,574 |
| M FORK WILDCAT CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1942 | 2,573 |
| HATCHEL CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1973 | 2,571 |
| GRAND RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1932 | 2,570 |
| BRESLAU CREEK | Nebraska | Scour Critical — Countermeasures Installed | Poor | 1934 | 2,570 |
| Banana River | Florida | Scour Critical — Countermeasures Installed | Fair | 1927 | 2,569 |
| FAIRFIELD CANAL | California | Scour Critical — Countermeasures Installed | Fair | 1950 | 2,569 |
| WASTEWAY-FAIRFIELD CANAL | California | Scour Critical — Countermeasures Installed | Good | 1960 | 2,569 |
| Crystal River | Colorado | Scour Critical — Countermeasures Installed | Fair | 1950 | 2,569 |
| OVER CUSSEWAGO CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1955 | 2,568 |
| BAYOU DARBONNE | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1978 | 2,567 |
| NINNESCAH (S F) RIVER | Kansas | Scour Critical — Countermeasures Installed | Good | 1988 | 2,565 |
| SNAKE CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1944 | 2,561 |
| COHAS BROOK | New Hampshire | Scour Critical — Countermeasures Installed | Good | 1900 | 2,560 |
| SIMMONS CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1921 | 2,556 |
| FROG CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1974 | 2,555 |
| LITTLE SWATARA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 2,553 |
| CANASAWACTA CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1937 | 2,552 |
| OVER CROOKED CREEK TRIB | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1921 | 2,552 |
| POWDER RIVER (BRIDGE ST) | Oregon | Scour Critical — Countermeasures Installed | Fair | 1933 | 2,551 |
| MUDDY RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1932 | 2,551 |
| TRIB OF KICKAPOO CR | Illinois | Scour Critical — Countermeasures Installed | Fair | 1928 | 2,550 |
| MISSISSIPPI RIVER | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1971 | 2,550 |
| SAND CREEK | North Dakota | Scour Critical — Countermeasures Installed | Fair | 1960 | 2,550 |
| COWANSHANNOCK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1962 | 2,549 |
| THREE MILE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1935 | 2,548 |
| SADDLE RIVER (E. BRANCH) | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1946 | 2,545 |
| SUGAR RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1954 | 2,536 |
| W BR TITTABAWASSEE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1954 | 2,536 |
| LITTLE TOBACCO RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1958 | 2,536 |
| TITTABAWASSEE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1928 | 2,536 |
| SPRING BRANCH | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1963 | 2,534 |
| STONEY CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1929 | 2,533 |
| MAPLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Poor | 1929 | 2,533 |
| ST AUGUSTA CREEK | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1935 | 2,533 |
| COTTONWOOD CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1946 | 2,533 |
| RUTHERFORD FK.OBION RIVE | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1975 | 2,532 |
| EIGHT MILE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1939 | 2,528 |
| ARROYO DEL PUERTO | New Mexico | Scour Critical — Countermeasures Installed | Fair | 1957 | 2,527 |
| MADISON RIVER | Wyoming | Scour Critical — Countermeasures Installed | Poor | 1958 | 2,525 |
| Dodson Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,525 |
| Roach Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1965 | 2,525 |
| Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1964 | 2,525 |
| WILDCAT CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1967 | 2,524 |
| JONES CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1931 | 2,524 |
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.