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 |
|---|---|---|---|---|---|
| JUAN MARTIN RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1916 | 4,000 |
| SAWMILL RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1928 | 4,000 |
| PACK RIVER | Idaho | Scour Critical — Countermeasures Installed | Fair | 1978 | 4,000 |
| BLUE RIBBON ARROYO | Colorado | Scour Critical — Countermeasures Installed | Fair | 1950 | 4,000 |
| W BRANCH SAUGATUCK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1957 | 4,000 |
| IRENE CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1954 | 4,000 |
| ANDOVER BRANCH | Vermont | Scour Critical — Countermeasures Installed | Fair | 1933 | 4,000 |
| SPRING CREEK | Texas | Scour Critical — Countermeasures Installed | Good | 1989 | 4,000 |
| Hogskin Lake Creek | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1989 | 4,000 |
| MANCOS RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1959 | 4,000 |
| INDIAN CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1959 | 4,000 |
| Partin Canal | Florida | Scour Critical — Countermeasures Installed | Fair | 1973 | 4,000 |
| WARRIOR RIVER RELIEF | Alabama | Scour Critical — Countermeasures Installed | Fair | 1927 | 3,997 |
| WARRIOR RIVER RELIEF | Alabama | Scour Critical — Countermeasures Installed | Fair | 1927 | 3,997 |
| WARRIOR RIVER RELIEF | Alabama | Scour Critical — Countermeasures Installed | Fair | 1941 | 3,997 |
| PASCACK BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1981 | 3,997 |
| SUGAR CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Good | 1957 | 3,993 |
| BRANCH OF POMPESTON CK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1961 | 3,992 |
| ANDERSON ARROYO | Colorado | Scour Critical — Countermeasures Installed | Poor | 1931 | 3,981 |
| HAIRS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1960 | 3,980 |
| NAVASOTA RIVER E RELIEF | Texas | Scour Critical — Countermeasures Installed | Fair | 1940 | 3,978 |
| SULLIVAN DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1987 | 3,977 |
| SYCAMORE RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1950 | 3,974 |
| ELDER RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1951 | 3,972 |
| CANOVANAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1947 | 3,972 |
| PRAIRIE CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1985 | 3,969 |
| QUITTAPAHILLA CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1967 | 3,968 |
| CLEAR BROOK | Delaware | Scour Critical — Countermeasures Installed | Fair | 1919 | 3,966 |
| N CHUCTANUNDA CK | New York | Scour Critical — Countermeasures Installed | Poor | 1912 | 3,960 |
| BUCK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1932 | 3,958 |
| TRIB DELAWARE RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 3,958 |
| DYERS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1929 | 3,958 |
| HOUGHS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1933 | 3,958 |
| SANDY HOOK DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1952 | 3,957 |
| DELAWARE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1952 | 3,956 |
| DELAWARE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1952 | 3,956 |
| DEER CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1987 | 3,955 |
| CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1954 | 3,955 |
| CREEK | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1960 | 3,954 |
| EAST BR BRANDYWINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1941 | 3,954 |
| RED GULLY | Texas | Scour Critical — Countermeasures Installed | Fair | 1977 | 3,953 |
| ST JOSEPH RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1947 | 3,950 |
| DRAW | Texas | Scour Critical — Countermeasures Installed | Fair | 1960 | 3,949 |
| Wash | Arizona | Scour Critical — Countermeasures Installed | Good | 1951 | 3,947 |
| N TUPAWEK BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1978 | 3,947 |
| COUNTY DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1939 | 3,942 |
| ROSILLO CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 2005 | 3,942 |
| PAWNEE CREEK | Nebraska | Scour Critical — Countermeasures Installed | Fair | 1935 | 3,940 |
| TEETER CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1974 | 3,939 |
| ECHO CREEK | Utah | Scour Critical — Countermeasures Installed | Fair | 1924 | 3,938 |
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.