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 |
|---|---|---|---|---|---|
| BRUSH CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1955 | 2,681 |
| BEAR TRAP CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1955 | 2,681 |
| POWELL CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1985 | 2,680 |
| WILSON CREEK | California | Scour Critical — Countermeasures Installed | Good | 1927 | 2,678 |
| YAKIMA RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1947 | 2,678 |
| BLACK CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1929 | 2,675 |
| Howell Creek | Florida | Scour Critical — Countermeasures Installed | Good | 1981 | 2,670 |
| OVER MARSH CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1925 | 2,670 |
| SIPSEY RIVER RELIEF | Alabama | Scour Critical — Countermeasures Installed | Fair | 1956 | 2,667 |
| FULTON CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1926 | 2,667 |
| LAKE CR | Washington | Scour Critical — Countermeasures Installed | Fair | 1963 | 2,666 |
| PEMIGEWASSET RIVER NHRR | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1937 | 2,666 |
| TWENTYTWO CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1952 | 2,662 |
| MAHANTANGO CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Good | 1930 | 2,660 |
| LACKAWANNA RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1961 | 2,658 |
| EVANS CREEK | Michigan | Scour Critical — Countermeasures Installed | Poor | 1934 | 2,657 |
| E BR BIG CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1960 | 2,656 |
| JOHNSON CR | Washington | Scour Critical — Countermeasures Installed | Fair | 1962 | 2,655 |
| HUNTER WASH | New Mexico | Scour Critical — Countermeasures Installed | Good | 1984 | 2,653 |
| WARD CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1984 | 2,652 |
| FIVE MILE CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1970 | 2,650 |
| NINE MILE CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1978 | 2,650 |
| ELK CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1957 | 2,644 |
| CANEY CREEK | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1954 | 2,642 |
| LAMPREY RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1932 | 2,642 |
| BEAVER CREEK REL. | Alabama | Scour Critical — Countermeasures Installed | Fair | 1976 | 2,640 |
| SOL SHANK DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1988 | 2,639 |
| PUGET SOUND | Washington | Scour Critical — Countermeasures Installed | Fair | 1993 | 2,635 |
| ABIQUA CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1954 | 2,635 |
| CHAPEPEELA CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1957 | 2,634 |
| CHAP CREEK RELIEF | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1957 | 2,634 |
| WALNUT FORK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1953 | 2,630 |
| SYCAMORE CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1960 | 2,630 |
| EAST BRANCH SALMON BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1937 | 2,630 |
| JESTER CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1987 | 2,627 |
| ONION CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1970 | 2,627 |
| ONION CREEK | Kansas | Scour Critical — Countermeasures Installed | Good | 1970 | 2,627 |
| FLAT RIVER | Louisiana | Scour Critical — Countermeasures Installed | Poor | 1964 | 2,626 |
| BERG SLOUGH | Washington | Scour Critical — Countermeasures Installed | Poor | 1964 | 2,622 |
| LOSTINE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1953 | 2,619 |
| WOLF RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1965 | 2,619 |
| LITTLE PAINT CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1947 | 2,617 |
| ROYCE BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1978 | 2,617 |
| MOSHER CREEK | Wisconsin | Scour Critical — Countermeasures Installed | Fair | 1950 | 2,616 |
| FRANKS. BR.JUNIATA RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1937 | 2,615 |
| CONTOOCOOK RIVER | New Hampshire | Scour Critical — Countermeasures Installed | Fair | 1981 | 2,615 |
| CLIMBERS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1982 | 2,614 |
| POWELL CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1940 | 2,612 |
| RIDLEY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1960 | 2,611 |
| SPRDG TEX LINE JOHNSON B | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1979 | 2,606 |
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.