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 |
|---|---|---|---|---|---|
| BROOKHOLLOW CREEK | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1975 | 19,279 |
| Spring Creek-Springdale | Arkansas | Scour Critical — Countermeasures Installed | Fair | 2008 | 19,275 |
| MONTGOMERY CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1965 | 19,260 |
| POTRERO CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1926 | 19,252 |
| ARROYO DEL VALLE | California | Scour Critical — Countermeasures Installed | Poor | 1940 | 19,250 |
| MUDDY RIVER | Nevada | Scour Critical — Countermeasures Installed | Fair | 1962 | 19,250 |
| MUDDY RIVER | Nevada | Scour Critical — Countermeasures Installed | Fair | 1962 | 19,250 |
| MANADAS CREEK TRIBUTARY | Texas | Scour Critical — Countermeasures Installed | Good | 1998 | 19,242 |
| CHANNEL | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1980 | 19,200 |
| COLES BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1931 | 19,200 |
| CONNECTICUT RIVER NECRR | Vermont | Scour Critical — Countermeasures Installed | Poor | 1966 | 19,185 |
| MUCKINIPATTUS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1925 | 19,177 |
| NS RR MCCULLOCH DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1964 | 19,158 |
| WILSON CREEK RELIEF | Texas | Scour Critical — Countermeasures Installed | Fair | 1957 | 19,136 |
| BOWLEES CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1989 | 19,100 |
| ROGUE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1960 | 19,047 |
| CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1961 | 19,034 |
| CREEK | Oregon | Scour Critical — Countermeasures Installed | Good | 1956 | 19,034 |
| KINNICKINNICK RIVER | Wisconsin | Scour Critical — Countermeasures Installed | Poor | 1987 | 19,025 |
| JOHNSON FK/JOHNSON FK RD | Indiana | Scour Critical — Countermeasures Installed | Good | 1960 | 19,024 |
| IVANPAH DITCH | California | Scour Critical — Countermeasures Installed | Good | 1963 | 19,000 |
| YANTIC RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1959 | 19,000 |
| BRANCH WISSAHICKON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1957 | 18,982 |
| SWAMP CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1935 | 18,981 |
| DUCK CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1952 | 18,979 |
| JOHNSON FK/JOHNSON FK RD | Indiana | Scour Critical — Countermeasures Installed | Fair | 1960 | 18,929 |
| MT HP BY N SEC RR 114 LP | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1929 | 18,924 |
| MANOA-PALOLO STRM | Hawaii | Scour Critical — Countermeasures Installed | Good | 1950 | 18,917 |
| ARKANSAS RIVER | Kansas | Scour Critical — Countermeasures Installed | Fair | 1966 | 18,907 |
| COCAL RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1959 | 18,900 |
| NIGUA RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1971 | 18,900 |
| SADDLE RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1922 | 18,844 |
| NOLANDS FORK | Indiana | Scour Critical — Countermeasures Installed | Good | 1959 | 18,841 |
| RABBIT RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1957 | 18,817 |
| UNAMI CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1965 | 18,805 |
| NORWALK RIVER | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1928 | 18,800 |
| NS RR MCCULLOCH DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1964 | 18,794 |
| WHITE CLAY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1927 | 18,776 |
| Canal 100-A | Florida | Scour Critical — Countermeasures Installed | Poor | 1966 | 18,758 |
| JEFFERIES CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1966 | 18,750 |
| TRUCKEE RIVER & SPRR | Nevada | Scour Critical — Countermeasures Installed | Fair | 1964 | 18,750 |
| TRUCKEE RIVER & SPRR | Nevada | Scour Critical — Countermeasures Installed | Fair | 1964 | 18,750 |
| THOMPSON RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 18,741 |
| SYMONS CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1965 | 18,703 |
| SYMONS CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1965 | 18,703 |
| E FK/E FK WHITEWATER RIV | Indiana | Scour Critical — Countermeasures Installed | Poor | 1959 | 18,702 |
| WILSON CREEK RELIEF | Texas | Scour Critical — Countermeasures Installed | Fair | 1957 | 18,700 |
| GREENS BAYOU | Texas | Scour Critical — Countermeasures Installed | Fair | 1986 | 18,696 |
| GRANNEYS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1979 | 18,687 |
| BRANCH SHABAKUNK CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1950 | 18,625 |
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.