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 |
|---|---|---|---|---|---|
| PETERSON CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 6,611 |
| TUPPER RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1934 | 6,610 |
| Sparkill Creek | New York | Scour Critical — Countermeasures Installed | Poor | 1955 | 6,609 |
| MILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1936 | 6,605 |
| RAMBIN BAYOU | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1978 | 6,604 |
| GILLS CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1972 | 6,600 |
| COAL CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1921 | 6,600 |
| MILL CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1965 | 6,600 |
| GILDER CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1964 | 6,600 |
| ROCKY RIVER | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1971 | 6,600 |
| SANTIAGO CHANNEL | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1919 | 6,600 |
| CANEY FORK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1986 | 6,600 |
| CEDAR CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1947 | 6,600 |
| MID-PRONG ST MARYS RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1948 | 6,600 |
| ARKANSAS RIVER TRIB. | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1980 | 6,598 |
| PETERS RIVER | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1900 | 6,592 |
| SUTHERLIN CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1921 | 6,589 |
| GREENS BAYOU | Texas | Scour Critical — Countermeasures Installed | Good | 1995 | 6,587 |
| GREENS BAYOU | Texas | Scour Critical — Countermeasures Installed | Good | 1995 | 6,587 |
| BIG CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 2006 | 6,586 |
| WALNUT RIVER OVERFLOW | Kansas | Scour Critical — Countermeasures Installed | Good | 1987 | 6,583 |
| WALNUT RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1956 | 6,583 |
| WILLOW RUN | Michigan | Scour Critical — Countermeasures Installed | Poor | 1928 | 6,582 |
| BIG SABLE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1959 | 6,578 |
| VIEJAS CREEK | California | Scour Critical — Countermeasures Installed | Good | 1933 | 6,575 |
| HERSEY RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1958 | 6,569 |
| PLEASANT BROOK | New Jersey | Scour Critical — Countermeasures Installed | Good | 1945 | 6,566 |
| POMPESTON CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1970 | 6,554 |
| WEST COLYELL CR | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1952 | 6,554 |
| HUMBOLDT RVR | Nevada | Scour Critical — Countermeasures Installed | Fair | 1986 | 6,550 |
| MISS RIV/RR/MSS6000 | Illinois | Scour Critical — Countermeasures Installed | Fair | 1874 | 6,550 |
| KLICKITAT CREEK | Washington | Scour Critical — Countermeasures Installed | Good | 1937 | 6,548 |
| TOWNSENDS INLET | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1939 | 6,548 |
| SINGSING CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1924 | 6,547 |
| Spring Draw | Texas | Scour Critical — Countermeasures Installed | Fair | 1960 | 6,541 |
| WATER FORT RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1957 | 6,538 |
| WILLAMETTE R/RIVER RD S | Oregon | Scour Critical — Countermeasures Installed | Fair | 1951 | 6,536 |
| N FORK ASH CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1957 | 6,536 |
| SANTA CLARA RIVER | Utah | Scour Critical — Countermeasures Installed | Fair | 1931 | 6,533 |
| PINE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 6,532 |
| PINE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 6,532 |
| LONG TOM RIVER OVERFLOW | Oregon | Scour Critical — Countermeasures Installed | Good | 1988 | 6,530 |
| PANTHER CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1902 | 6,528 |
| MUSCONETCONG RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1925 | 6,520 |
| WALLKILL RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1875 | 6,520 |
| SO SABINE RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1964 | 6,515 |
| WALLKILL RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1910 | 6,513 |
| LOANTAKA BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1936 | 6,512 |
| HUMPTULIPS RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1956 | 6,510 |
| ARKANSAS RIVER | Colorado | Scour Critical — Countermeasures Installed | Fair | 1959 | 6,509 |
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.