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 |
|---|---|---|---|---|---|
| Johnson Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1991 | 45,032 |
| NASSAU RIVER | Florida | Scour Critical — Countermeasures Installed | Poor | 1967 | 45,000 |
| NASSAU RIVER | Florida | Scour Critical — Countermeasures Installed | Poor | 1967 | 45,000 |
| LICK CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1963 | 44,678 |
| MAHORAS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1928 | 44,635 |
| NESHAMINY CR & APPL 276 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1964 | 44,629 |
| PIEDRAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1950 | 44,600 |
| Willamette River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1953 | 44,573 |
| MONOCACY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1941 | 44,528 |
| BIG BRANCH | Louisiana | Scour Critical — Countermeasures Installed | Good | 1969 | 44,252 |
| BLOOD RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1968 | 44,252 |
| COOLEY BRANCH | Louisiana | Scour Critical — Countermeasures Installed | Good | 1960 | 44,225 |
| COOLEY BRANCH | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1960 | 44,225 |
| BOND CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1929 | 44,043 |
| Mill Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1956 | 43,693 |
| WATER FISH BROOK | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1950 | 43,600 |
| INDIAN CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 43,502 |
| WATER FISH BROOK | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1976 | 43,300 |
| SAW MILL RIVER | New York | Scour Critical — Countermeasures Installed | Poor | 1927 | 43,153 |
| WOLF CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1957 | 43,065 |
| SAW MILL RIVER | New York | Scour Critical — Countermeasures Installed | Fair | 1933 | 42,645 |
| CENTRAL OREGON CANAL | Oregon | Scour Critical — Countermeasures Installed | Fair | 1966 | 42,538 |
| GILLS CREEK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1982 | 42,500 |
| GILLS CREEK | South Carolina | Scour Critical — Countermeasures Installed | Good | 1982 | 42,500 |
| SAW MILL RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1926 | 42,292 |
| RAHWAY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1941 | 42,130 |
| RAHWAY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1917 | 42,130 |
| OAKEYS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1934 | 42,085 |
| Loxahatchee River | Florida | Scour Critical — Countermeasures Installed | Fair | 1975 | 42,000 |
| E FORK LEWIS RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1939 | 41,939 |
| LITTLE OGEECHEE RIVER | Georgia | Scour Critical — Countermeasures Installed | Good | 1966 | 41,900 |
| PILCHUCK CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1973 | 41,822 |
| PILCHUCK CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1954 | 41,822 |
| CUB CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1960 | 41,499 |
| CUB CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1960 | 41,499 |
| TOBY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1963 | 41,421 |
| TOBESOFKEE CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1970 | 41,400 |
| LANGHAM CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1981 | 41,301 |
| CYPRESS CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1959 | 41,152 |
| CYPRESS CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1959 | 41,152 |
| SWIFT CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1966 | 41,000 |
| SWIFT CREEK | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1966 | 41,000 |
| US 202 & RAMAPO RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1932 | 41,000 |
| INDIAN CREEK CANAL | Florida | Scour Critical — Countermeasures Installed | Poor | 1953 | 41,000 |
| MANATEE RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1986 | 41,000 |
| MACOPIN RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1924 | 40,996 |
| MILL CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1929 | 40,878 |
| MILL CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1949 | 40,878 |
| BAYLISS STATE DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 40,874 |
| BAYLISS STATE DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 40,874 |
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.