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 |
|---|---|---|---|---|---|
| TRUCKEE RVR | Nevada | Scour Critical — Countermeasures Installed | Fair | 1921 | 13,000 |
| KOOTENAI R;UPRR;BNNRS FY | Idaho | Scour Critical — Countermeasures Installed | Fair | 1984 | 13,000 |
| CEDAR RIVER | Iowa | Scour Critical — Countermeasures Installed | Fair | 1920 | 13,000 |
| PEACE CREEK RELIEF | Florida | Scour Critical — Countermeasures Installed | Good | 1951 | 13,000 |
| Spout Spring Br. - Fay. | Arkansas | Scour Critical — Countermeasures Installed | Poor | 1940 | 13,000 |
| WATER SUDBURY RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1967 | 13,000 |
| NEUSE RIVER | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1961 | 13,000 |
| LITTLE CREEK | North Carolina | Scour Critical — Countermeasures Installed | Poor | 1979 | 13,000 |
| BOOKER CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1965 | 13,000 |
| TOWAMENCIN CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1928 | 12,986 |
| MAURICE RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1970 | 12,950 |
| POST OAK CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1971 | 12,948 |
| POST OAK CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1971 | 12,948 |
| Larimer Co. Canal No. 2 | Colorado | Scour Critical — Countermeasures Installed | Fair | 1920 | 12,947 |
| GAYHEAD POND INLT | New York | Scour Critical — Countermeasures Installed | Fair | 1935 | 12,935 |
| MANOA PALOLO STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1937 | 12,921 |
| MEADOW STREAM | New York | Scour Critical — Countermeasures Installed | Fair | 1930 | 12,909 |
| CROSS BAYOU CANAL | Florida | Scour Critical — Countermeasures Installed | Good | 1984 | 12,900 |
| SWARTZ CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1918 | 12,900 |
| SELSERS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1938 | 12,900 |
| PENNYPACK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1930 | 12,877 |
| PENNYPACK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1930 | 12,877 |
| WAXHAW CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1973 | 12,850 |
| ANAHULU STRM | Hawaii | Scour Critical — Countermeasures Installed | Poor | 1921 | 12,850 |
| CANE CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1974 | 12,850 |
| KALAMAZOO RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1973 | 12,841 |
| PEQUANNOCK RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1925 | 12,830 |
| LA NANA BAYOU | Texas | Scour Critical — Countermeasures Installed | Fair | 1962 | 12,825 |
| PASCACK BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1975 | 12,821 |
| WATERWAY | Delaware | Scour Critical — Countermeasures Installed | Fair | 1925 | 12,820 |
| WATER SPICKET RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Poor | 1900 | 12,808 |
| WAGNER CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1937 | 12,804 |
| E FORK CARSON RVR | Nevada | Scour Critical — Countermeasures Installed | Fair | 1951 | 12,800 |
| BIG DUTCHMAN CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1979 | 12,800 |
| TRUCKEE RIVER | Nevada | Scour Critical — Countermeasures Installed | Poor | 1966 | 12,800 |
| JAGUEYES CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1967 | 12,800 |
| COTTONWOOD SLOUGH | Nevada | Scour Critical — Countermeasures Installed | Good | 1952 | 12,800 |
| JAGUEYES CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1955 | 12,800 |
| HAKIPUU STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1922 | 12,800 |
| COAST FK WILLAMETTE RIV | Oregon | Scour Critical — Countermeasures Installed | Fair | 1953 | 12,757 |
| DUNCAN CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1960 | 12,750 |
| DUNCAN CREEK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1960 | 12,750 |
| BUCK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1930 | 12,743 |
| COBBS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1909 | 12,715 |
| CUIVRE RVR CRD DYER RD | Missouri | Scour Critical — Countermeasures Installed | Fair | 1985 | 12,712 |
| LAUHULU STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1937 | 12,700 |
| VALENCIANO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1947 | 12,700 |
| KAWAILOA STRM | Hawaii | Scour Critical — Countermeasures Installed | Good | 1929 | 12,700 |
| LITTLE OTTER CREEK | Vermont | Scour Critical — Countermeasures Installed | Fair | 1959 | 12,700 |
| MILLSTONE RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1970 | 12,700 |
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.