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 |
|---|---|---|---|---|---|
| RAHWAY RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1914 | 25,190 |
| SUGAR CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1963 | 25,145 |
| CLEAR CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1964 | 25,145 |
| CLEAR CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1964 | 25,145 |
| DOCTORS CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1951 | 25,095 |
| SOUTH BR RARITAN RIVER | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1921 | 25,056 |
| ROCK CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1953 | 25,052 |
| KALIHI STRM | Hawaii | Scour Critical — Countermeasures Installed | Fair | 1933 | 25,033 |
| AIRES CANAL | Florida | Scour Critical — Countermeasures Installed | Good | 1999 | 25,000 |
| COMB MERIMAC RIV/ACCESS | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1918 | 25,000 |
| LITTLE WHITE LICK CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1976 | 24,998 |
| LITTLE WHITE LICK CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1976 | 24,998 |
| BLAKLEY DRAIN | Michigan | Scour Critical — Countermeasures Installed | Fair | 1986 | 24,955 |
| DUCK RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1947 | 24,920 |
| DUCK RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1948 | 24,920 |
| BIG COTTONWOOD CREEK | Texas | Scour Critical — Countermeasures Installed | Poor | 1929 | 24,909 |
| WALTON CREEK | Texas | Scour Critical — Countermeasures Installed | Fair | 1949 | 24,899 |
| BLACK CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1966 | 24,800 |
| SKOOKUMCHUCK RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1951 | 24,769 |
| SKOOKUMCHUCK RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1951 | 24,769 |
| LITTLE CHIQUES CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1968 | 24,666 |
| PIEDRAS RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1989 | 24,600 |
| KALAMAZOO RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1966 | 24,600 |
| KEEGANS BAYOU | Texas | Scour Critical — Countermeasures Installed | Good | 1988 | 24,543 |
| SNAKE R;FRUITLAND BRIDGE | Idaho | Scour Critical — Countermeasures Installed | Good | 1967 | 24,500 |
| NACHES RIVER | Washington | Scour Critical — Countermeasures Installed | Fair | 1932 | 24,488 |
| Conewago Creek | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1949 | 24,423 |
| Yamhill River Overflow | Oregon | Scour Critical — Countermeasures Installed | Fair | 1963 | 24,417 |
| KALAMAZOO RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1964 | 24,400 |
| PINE BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1921 | 24,340 |
| COLES BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1962 | 24,330 |
| ASSISCUNK CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1963 | 24,327 |
| BIG WATEREE CK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1979 | 24,300 |
| BIG WATEREE CK | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1979 | 24,300 |
| ASSISCUNK CREEK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1935 | 24,298 |
| WILLOUGHBY BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1930 | 24,297 |
| SR 10 RL / ELK RIVER | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1968 | 24,286 |
| SNI-A-BAR CR | Missouri | Scour Critical — Countermeasures Installed | Fair | 1948 | 24,233 |
| SOUTHAMPTON CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1966 | 24,196 |
| KALAMAZOO RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 2024 | 24,126 |
| JEFFERIES CREEK | South Carolina | Scour Critical — Countermeasures Installed | Poor | 1938 | 24,100 |
| BIG DRY CREEK | Colorado | Scour Critical — Countermeasures Installed | Fair | 1970 | 24,040 |
| ASH CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1989 | 24,002 |
| LOTTS CREEK | Georgia | Scour Critical — Countermeasures Installed | Good | 1976 | 23,900 |
| HARRISONS BROOK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1971 | 23,883 |
| Willow Brook | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1968 | 23,861 |
| GOODBYS LAKE | Florida | Scour Critical — Countermeasures Installed | Fair | 1967 | 23,750 |
| OYSTER CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1967 | 23,730 |
| ORE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1940 | 23,661 |
| ORE CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1959 | 23,661 |
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.