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 |
|---|---|---|---|---|---|
| DARBY CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 9,364 |
| TIDBURY BRANCH | Delaware | Scour Critical — Countermeasures Installed | Fair | 1919 | 9,355 |
| LOOSAHATCHIE RIVER | Tennessee | Scour Critical — Countermeasures Installed | Poor | 1970 | 9,352 |
| OLIVER CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1926 | 9,349 |
| SAND CREEK | Indiana | Scour Critical — Countermeasures Installed | Good | 1994 | 9,349 |
| WHITE RIVER | Indiana | Scour Critical — Countermeasures Installed | Poor | 1973 | 9,340 |
| N BR PENNSAUKEN CREEK | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1941 | 9,324 |
| PINEY CREEK | Alabama | Scour Critical — Countermeasures Installed | Fair | 1959 | 9,320 |
| Upper Chloe Creek | Kentucky | Scour Critical — Countermeasures Installed | Poor | 1940 | 9,300 |
| SUSQUEHANNA RIVER | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1914 | 9,300 |
| NEW CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1924 | 9,300 |
| CUSHING CREEK | Florida | Scour Critical — Countermeasures Installed | Fair | 1948 | 9,300 |
| WADBOO SWAMP | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1973 | 9,300 |
| ST. JOSEPH SOUND (ICWW) | Florida | Scour Critical — Countermeasures Installed | Fair | 1963 | 9,300 |
| CLINTON RIVER | Michigan | Scour Critical — Countermeasures Installed | Good | 1947 | 9,300 |
| LIND COULEE | Washington | Scour Critical — Countermeasures Installed | Fair | 1954 | 9,298 |
| EAST BRANCH DEEP CREEK | Kansas | Scour Critical — Countermeasures Installed | Fair | 1962 | 9,282 |
| COYOTE CREEK | California | Scour Critical — Countermeasures Installed | Fair | 1930 | 9,275 |
| WATER VINE BROOK | Massachusetts | Scour Critical — Countermeasures Installed | Fair | 1956 | 9,271 |
| WHITE RIVER | Indiana | Scour Critical — Countermeasures Installed | Good | 1971 | 9,270 |
| ABERNETHY CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1956 | 9,270 |
| ABERNETHY CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1956 | 9,270 |
| GRAYS CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1956 | 9,267 |
| CAYUGA CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1983 | 9,264 |
| PASCACK BROOK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1900 | 9,261 |
| POHOPOCO CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1934 | 9,256 |
| SWAMP CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1947 | 9,235 |
| MINE RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1928 | 9,235 |
| CULVERT BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Good | 1925 | 9,234 |
| COOKS RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1926 | 9,221 |
| DOUBLE BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1963 | 9,213 |
| UMATILLA R/UPRR/USRS CAN | Oregon | Scour Critical — Countermeasures Installed | Fair | 1968 | 9,213 |
| DOUBLE BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1963 | 9,213 |
| SUMROW CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1963 | 9,213 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1965 | 9,213 |
| SUMROW CREEK | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1963 | 9,213 |
| BRANCH | Tennessee | Scour Critical — Countermeasures Installed | Fair | 1958 | 9,213 |
| RICKETTS BRANCH | Texas | Scour Critical — Countermeasures Installed | Fair | 1964 | 9,212 |
| CARLANNA CREEK | Alaska | Scour Critical — Countermeasures Installed | Fair | 1973 | 9,210 |
| TIOUGHNIOGA RIVER | New York | Scour Critical — Countermeasures Installed | Fair | 1947 | 9,205 |
| LAURAMIE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1925 | 9,205 |
| SAMMAMISH R | Washington | Scour Critical — Countermeasures Installed | Good | 1963 | 9,203 |
| Trib to Spruce Creek | Florida | Scour Critical — Countermeasures Installed | Good | 1961 | 9,200 |
| SMACKS BAYOU | Florida | Scour Critical — Countermeasures Installed | Poor | 1965 | 9,200 |
| COFFEE POT BAYOU | Florida | Scour Critical — Countermeasures Installed | Fair | 1928 | 9,200 |
| UPCHURCHES POND | North Carolina | Scour Critical — Countermeasures Installed | Fair | 1984 | 9,200 |
| PORTUGUES RIVER | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1948 | 9,200 |
| WYALUSING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1970 | 9,182 |
| SHELDRAKE RIVER | New York | Scour Critical — Countermeasures Installed | Fair | 1935 | 9,181 |
| BIG TIMBER CREEK | New Jersey | Scour Critical — Countermeasures Installed | Poor | 1934 | 9,175 |
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.