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 |
|---|---|---|---|---|---|
| PLUM CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1955 | 31,883 |
| MIDDLE BR CLINTON RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1996 | 31,800 |
| BRANCH BROWNS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1960 | 31,662 |
| WAILUA RIVER | Hawaii | Scour Critical — Countermeasures Installed | Poor | 1945 | 31,600 |
| WAILUA RIVER | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1920 | 31,600 |
| BUFFALO CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1991 | 31,576 |
| WATER CHARLES RIVER | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1888 | 31,500 |
| Colorado River | Arizona | Scour Critical — Countermeasures Installed | Fair | 1987 | 31,500 |
| BARNETT ROAD AT BEAR CR | Oregon | Scour Critical — Countermeasures Installed | Fair | 2009 | 31,423 |
| PINE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1925 | 31,339 |
| BLACK CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1949 | 31,322 |
| RUSH CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1933 | 31,311 |
| SYCAMORE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1956 | 31,200 |
| WILLOW MEADOW BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1959 | 31,084 |
| WATER MARTINS BROOK | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1903 | 31,080 |
| Indian Bend Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1978 | 31,074 |
| Rillito Creek | Arizona | Scour Critical — Countermeasures Installed | Fair | 1970 | 31,053 |
| Mud Creek-Washington | Arkansas | Scour Critical — Countermeasures Installed | Fair | 1928 | 31,000 |
| MANALAPAN BROOK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1927 | 30,910 |
| WILLAMETTE RIVER | Oregon | Scour Critical — Countermeasures Installed | Fair | 1912 | 30,871 |
| MIDDLE ROUGE RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1930 | 30,856 |
| GRANDE DE ARECIBO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Good | 1980 | 30,800 |
| WHITE ROCK CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1986 | 30,728 |
| DES PLAINES RIVER | Illinois | Scour Critical — Countermeasures Installed | Fair | 1959 | 30,700 |
| DES PLAINES RIVER | Illinois | Scour Critical — Countermeasures Installed | Fair | 1959 | 30,700 |
| PASSAIC RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1951 | 30,700 |
| MIDDLE FK.FORKED DEER RI | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1967 | 30,652 |
| MIDDLE FK.FORKED DEER RI | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1968 | 30,652 |
| BUFFALO BAYOU | Texas | Scour Critical — Countermeasures Installed | Fair | 1968 | 30,601 |
| HONEYMAN CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1919 | 30,567 |
| WHITAKER BAYOU | Florida | Scour Critical — Countermeasures Installed | Good | 1923 | 30,500 |
| PHILLIPPI CREEK | Florida | Scour Critical — Countermeasures Installed | Good | 1986 | 30,500 |
| Biscayne Bay | Florida | Scour Critical — Countermeasures Installed | Fair | 1985 | 30,500 |
| TROUT RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1957 | 30,500 |
| PLUM CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1988 | 30,475 |
| PLUM CREEK | Michigan | Scour Critical — Countermeasures Installed | Good | 1964 | 30,475 |
| CIBOLO CREEK & AZTEC WAY | Texas | Scour Critical — Countermeasures Installed | Fair | 2002 | 30,473 |
| WOODEN BRIDGE RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1964 | 30,410 |
| HUMACAO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1965 | 30,350 |
| HUMACAO RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Poor | 1964 | 30,350 |
| MISSISSIPPI RVR UP RR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1990 | 30,251 |
| MISSISSIPPI RVR UP RR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1985 | 30,251 |
| PLYMOUTH CREEK / 3368-E4 | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1962 | 30,162 |
| W. BR. NESHAMINY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1934 | 30,106 |
| MILL CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1959 | 30,064 |
| PENNYPACK CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 30,060 |
| STEVENS CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1933 | 30,000 |
| MILL CREEK | Illinois | Scour Critical — Countermeasures Installed | Fair | 1953 | 29,900 |
| FANCY BLUFF CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1996 | 29,900 |
| TOBY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1941 | 29,878 |
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.