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 |
|---|---|---|---|---|---|
| NEW HOPE CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1979 | 14,500 |
| BRUSHY CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1969 | 14,500 |
| ICWW at Navarre | Florida | Scour Critical — Countermeasures Installed | Fair | 1960 | 14,500 |
| STONEY CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1977 | 14,500 |
| STONEY CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1960 | 14,500 |
| LITTLE NORTHEAST | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1994 | 14,500 |
| PARK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1985 | 14,495 |
| ULATIS CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1970 | 14,480 |
| Necanicum River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1930 | 14,464 |
| DAMARISCOTTA RIVER | Maine | Scour Critical — Countermeasures Installed | Fair | 1952 | 14,450 |
| ZACHARIAS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1970 | 14,446 |
| PENNA CANAL | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1934 | 14,443 |
| ST JOSEPH RIVER | Indiana | Scour Critical — Countermeasures Installed | Fair | 1927 | 14,437 |
| WAIOLANI STRM | Hawaii | Scour Critical — Countermeasures Installed | Good | 1934 | 14,427 |
| PUDDING RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1979 | 14,416 |
| PUDDING RIVER OVERFLOW | Oregon | Scour Critical — Countermeasures Installed | Fair | 1985 | 14,416 |
| BRANCH MARTINS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1954 | 14,412 |
| ISINGLASS RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Poor | 1951 | 14,407 |
| THREAD RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1995 | 14,407 |
| DORCHESTER WATERWAY | Florida | Scour Critical — Countermeasures Installed | Good | 1992 | 14,400 |
| LA PLATA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1979 | 14,400 |
| DICKISON RUN CREEK | Illinois | Scour Critical — Countermeasures Installed | Poor | 1958 | 14,400 |
| WATER ASSABET RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1886 | 14,400 |
| STRAWBERRY CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1969 | 14,400 |
| BRANCH NESHAMINY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1932 | 14,399 |
| FRY DITCH CREEK #2 | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1950 | 14,386 |
| WEBB DRAIN | Michigan | Scour Critical — Countermeasures Installed | Good | 1961 | 14,378 |
| WEBB DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 14,378 |
| SPROGELS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1910 | 14,340 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1930 | 14,335 |
| LITTLE BLACK CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1963 | 14,329 |
| LITTLE BLACK CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1963 | 14,329 |
| POND FLAT DITCH | Indiana | Scour Critical — Countermeasures Installed | Poor | 1946 | 14,325 |
| POND FLAT DITCH | Indiana | Scour Critical — Countermeasures Installed | Poor | 1946 | 14,325 |
| BLACK RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1955 | 14,315 |
| BLACK RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1930 | 14,315 |
| BLUE RIVER | Kansas | Scour Critical — Countermeasures Installed | Good | 1966 | 14,313 |
| BRANCH OF SALEM CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1919 | 14,306 |
| NEWMAN SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1973 | 14,300 |
| NEWMAN SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1973 | 14,300 |
| PASS MANCHAC | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1977 | 14,300 |
| CAGUITAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1999 | 14,300 |
| DEER CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1937 | 14,285 |
| SKIPPACK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1792 | 14,242 |
| RIPPOWAM RIVER | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1954 | 14,220 |
| CHIPPEWA RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1940 | 14,220 |
| Schooner Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1945 | 14,212 |
| GUATEMALA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1917 | 14,200 |
| NORTH ARCHIE CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1997 | 14,200 |
| ST. JOSEPH SOUND | Florida | Scour Critical — Countermeasures Installed | Fair | 1963 | 14,200 |
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.