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 |
|---|---|---|---|---|---|
| WEST FK WHITE LICK CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 65,674 |
| TOWAMENCIN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Good | 1955 | 65,329 |
| COLUMBIA RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1916 | 65,013 |
| COLUMBIA RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1958 | 65,013 |
| Columbia River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 65,013 |
| Columbia River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1916 | 65,013 |
| SABALOS CHANNEL | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1997 | 64,800 |
| CITY STREETS | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1970 | 64,059 |
| GILKEY CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1976 | 63,400 |
| PEQU RIV RR HMBG TPK SB | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1934 | 63,188 |
| WALNUT CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1967 | 62,400 |
| Clackamas River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 62,210 |
| Clackamas River | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 62,210 |
| BIG DRY CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1939 | 62,000 |
| NO.BR.RARITAN RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1934 | 61,761 |
| PIPE MAKERS CANAL | Georgia | Scour Critical — Countermeasures Installed | Good | 1976 | 61,100 |
| SAVANNAH RIVER | Georgia | Scour Critical — Countermeasures Installed | Fair | 1976 | 60,800 |
| WATER MERRIMACK RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1964 | 60,056 |
| MDOT RR COR & HURON RVR | Michigan | Scour Critical — Countermeasures Installed | Fair | 1956 | 59,888 |
| SCHUY.RIVER SERVICE RD. | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1963 | 59,527 |
| CLEAR CREEK R | Colorado | Scour Critical — Countermeasures Installed | Fair | 1980 | 59,000 |
| THREAD CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1971 | 59,000 |
| CROOKFALL BROOK | Rhode Island | Scour Critical — Countermeasures Installed | Fair | 1924 | 58,520 |
| SANDY RUN / 3257-H10 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1958 | 58,495 |
| ROGUE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1969 | 58,420 |
| YELLOW WATER RIVER REL. | Louisiana | Scour Critical — Countermeasures Installed | Good | 1970 | 58,377 |
| Indian Bend Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1979 | 57,843 |
| MILFORD BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1938 | 57,832 |
| ROUGE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1967 | 57,795 |
| FLAT CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1963 | 57,600 |
| SIX MILE CYPRESS CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1981 | 57,000 |
| FOUNTAIN CREEK | Colorado | Scour Critical — Countermeasures Installed | Good | 1990 | 56,500 |
| UNNAMED CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1970 | 56,300 |
| ROUGE RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 2024 | 56,238 |
| WATER MERRIMACK RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1954 | 56,200 |
| CASS RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1961 | 56,192 |
| FLINT R W BLVD&R SIDE DR | Michigan | Scour Critical — Countermeasures Installed | Fair | 1976 | 56,000 |
| BEAVER CREEK | Michigan | Scour Critical — Countermeasures Installed | Good | 1964 | 55,558 |
| SANTA CATALINA CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1943 | 55,551 |
| WILLAMETTE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1967 | 55,375 |
| WILLAMETTE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1958 | 55,335 |
| CROW CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1964 | 55,046 |
| SIX MILE CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1981 | 55,000 |
| HEDDON CANAL | Florida | Scour Critical — Countermeasures Installed | Good | 1997 | 55,000 |
| MILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 54,739 |
| CONVERSE POND BROOK | Connecticut | Scour Critical — Countermeasures Installed | Fair | 1934 | 53,800 |
| MEDFORD VIADUCT | Oregon | Scour Critical — Countermeasures Installed | Fair | 1962 | 53,404 |
| SELSERS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1975 | 53,386 |
| PASSAIC RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1968 | 53,207 |
| POMPTON RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1935 | 53,150 |
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.