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 |
|---|---|---|---|---|---|
| BIG FIERY GIZZARD CREEK | Tennessee | Scour Critical — Countermeasures Installed | Good | 1963 | 36,821 |
| S BR ROCKAWAY CREEK | New Jersey | Scour Critical — Countermeasures Installed | Good | 1912 | 36,773 |
| ORTEGA RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1969 | 36,750 |
| ORTEGA RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1969 | 36,750 |
| BLACK CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1966 | 36,600 |
| LYLE CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1957 | 36,500 |
| Cave Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1976 | 36,376 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1962 | 36,373 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1962 | 36,373 |
| BR OF SAND CREEK | Michigan | Scour Critical — Countermeasures Installed | Good | 1961 | 36,338 |
| CLINTON R | Michigan | Scour Critical — Countermeasures Installed | Fair | 1929 | 36,241 |
| BUFFALO BAYOU | Texas | Scour Critical — Countermeasures Installed | Fair | 1962 | 36,165 |
| BEAR CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1961 | 36,121 |
| ROCKY BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1936 | 35,803 |
| QUINNIPIAC RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1946 | 35,800 |
| SADDLE RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1923 | 35,582 |
| SEALS GULLY | Texas | Scour Critical — Countermeasures Installed | Fair | 1986 | 35,579 |
| N. CHICKAMAUGA CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1975 | 35,457 |
| N. CHICKAMAUGA CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1975 | 35,457 |
| MALAPARDIS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1932 | 35,424 |
| BUFFALO RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1964 | 35,368 |
| BUFFALO RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1964 | 35,368 |
| SWEETWATER CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1973 | 35,300 |
| BRANCH NESHAMINY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1937 | 35,170 |
| MORGAN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1936 | 35,087 |
| WILLAMETTE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1926 | 35,000 |
| DISMAL SWAMP CANAL | Virginia | Scour Critical — Countermeasures Installed | Poor | 1934 | 35,000 |
| COULEE MINE | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1967 | 34,877 |
| LICK RUN | Indiana | Scour Critical — Countermeasures Installed | Fair | 1992 | 34,755 |
| MAMEYES RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1982 | 34,700 |
| JORDAN RIVER | Utah | Scour Critical — Countermeasures Installed | Fair | 1966 | 34,656 |
| MILLSTONE RIVER | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1915 | 34,650 |
| IRRIGATION DITCH | Puerto Rico | Scour Critical — Countermeasures Installed | Good | 1960 | 34,600 |
| LITTLE BLACK CREEK | Florida | Scour Critical — Countermeasures Installed | Poor | 1947 | 34,500 |
| WEST COLYELL CR | Louisiana | Scour Critical — Countermeasures Installed | Good | 1962 | 34,245 |
| JACOBS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1939 | 34,232 |
| BIG WALNUT CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 34,117 |
| BIG WALNUT CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 34,117 |
| ACCESS ROAD SILVER CR. | Indiana | Scour Critical — Countermeasures Installed | Fair | 1972 | 34,076 |
| JACOBS CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1972 | 34,076 |
| INDIAN BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 33,925 |
| CLEAR BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 33,925 |
| DRY BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 33,925 |
| MIDDLE SLOUGH | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 33,925 |
| YELLOW BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1962 | 33,925 |
| WATER MERRIMACK RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1925 | 33,900 |
| KEANANOIO STRM (O.B) | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1967 | 33,900 |
| MULBERRY CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1978 | 33,700 |
| QUINNIPIAC RIVER | Connecticut | Scour Critical — Countermeasures Installed | Poor | 1946 | 33,700 |
| AMAZON CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1977 | 33,645 |
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.