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 |
|---|---|---|---|---|---|
| ROCK PARK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1932 | 13,466 |
| TOWN CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1929 | 13,461 |
| STONY RUN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1942 | 13,454 |
| OVER FOURMILE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 13,435 |
| MAMBICHE CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1957 | 13,400 |
| MINILLAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1969 | 13,400 |
| INFIERNO CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1925 | 13,400 |
| WATER IPSWICH RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1850 | 13,394 |
| HYDE RUN | Delaware | Scour Critical — Countermeasures Installed | Fair | 1936 | 13,392 |
| Willamette River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1971 | 13,386 |
| W FRK E BR WHITE CLAY CR | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1965 | 13,382 |
| E.FRK. BR. WHITE CLAY CR | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1965 | 13,382 |
| DARBY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1931 | 13,380 |
| Kilchis R. & Possetti Rd | Oregon | Scour Critical — Countermeasures Installed | Poor | 1952 | 13,357 |
| MALHEUR RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1976 | 13,346 |
| SCATTER CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1926 | 13,337 |
| WISSAHICKON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1926 | 13,301 |
| MALIKO STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1961 | 13,300 |
| KENNEDY CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1960 | 13,297 |
| KENNEDY CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1960 | 13,297 |
| MILL RACE CANAL | Oregon | Scour Critical — Countermeasures Installed | Good | 1961 | 13,287 |
| OVER SIX MILE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1954 | 13,267 |
| SNAKE RIVER & BNRR | Washington | Scour Critical — Countermeasures Installed | Fair | 1950 | 13,260 |
| WOODEN BRIDGE RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1953 | 13,244 |
| PARK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1987 | 13,241 |
| ELKCAM WATERWAY | Florida | Scour Critical — Countermeasures Installed | Fair | 1991 | 13,200 |
| FISHERS FORK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1978 | 13,199 |
| WATER SANDERSDALE CANAL | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1900 | 13,189 |
| HURON RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1978 | 13,169 |
| WHIPPANY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1947 | 13,160 |
| POHATCONG CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1930 | 13,151 |
| MUSCONETCONG RIVER | New Jersey | Scour Critical — Countermeasures Installed | Good | 1924 | 13,131 |
| BRANCH MINE BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1921 | 13,131 |
| MINE BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1921 | 13,131 |
| YAKIMA RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1932 | 13,121 |
| BUSHKILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1886 | 13,117 |
| PAWCATUCK RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1974 | 13,100 |
| TURKEY CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 2005 | 13,100 |
| LITTLE WHITE LICK CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1958 | 13,094 |
| Arizona Canal | Arizona | Scour Critical — Countermeasures Installed | Fair | 1946 | 13,080 |
| POSSESSION SOUND | Washington | Scour Critical — Countermeasures Installed | Good | 2020 | 13,078 |
| LAHAWAY CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1939 | 13,054 |
| DARBY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1923 | 13,028 |
| TRIB. TO SAUCON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1922 | 13,025 |
| BYBERRY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1963 | 13,022 |
| BYBERRY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1963 | 13,022 |
| WATER SPICKET RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1850 | 13,010 |
| WATER PALMER RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1850 | 13,010 |
| PEACE CREEK RELIEF | Florida | Scour Critical — Countermeasures Installed | Good | 1951 | 13,000 |
| WATER SUDBURY RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1967 | 13,000 |
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.