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 |
|---|---|---|---|---|---|
| CREEK | Louisiana | Scour Critical — Countermeasures Installed | Good | 1966 | 3,768 |
| TANGIPAHOA RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 3,768 |
| CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1966 | 3,768 |
| COLUMBIA R | Washington | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,767 |
| OVER SWAMP RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1955 | 3,762 |
| GORDONS CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1925 | 3,757 |
| Patterson Wash | Arizona | Scour Critical — Countermeasures Installed | Fair | 1932 | 3,757 |
| SNAKE RIVER | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1980 | 3,750 |
| HILLSBOROUGH RIVER | Florida | Scour Critical — Countermeasures Installed | Fair | 1963 | 3,747 |
| LANDSMAN KILL | New York | Scour Critical — Countermeasures Installed | Fair | 1933 | 3,746 |
| EAST CANYON CREEK | Utah | Scour Critical — Countermeasures Installed | Fair | 1952 | 3,743 |
| INLET TO SNAG POND | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1984 | 3,742 |
| LAMB CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1959 | 3,741 |
| MCLAUGHLIN RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1900 | 3,740 |
| TRIB TO ROARING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1959 | 3,739 |
| MONTGOMERY DITCH | Indiana | Scour Critical — Countermeasures Installed | Fair | 1953 | 3,733 |
| JONES BEND CREEK | Tennessee | Scour Critical — Countermeasures Installed | Good | 1930 | 3,729 |
| ROBINSONS BRANCH RAH RIV | New Jersey | Scour Critical — Countermeasures Installed | Fair | 1921 | 3,725 |
| Boulder Creek | Oregon | Scour Critical — Countermeasures Installed | Fair | 1932 | 3,723 |
| MAPLE CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1989 | 3,723 |
| DEEDS CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1947 | 3,722 |
| BRAZOS RIVER | Texas | Scour Critical — Countermeasures Installed | Fair | 1969 | 3,720 |
| POCOTOPAUG CREEK | Connecticut | Scour Critical — Countermeasures Installed | Good | 2009 | 3,718 |
| GATE CREEK | Oregon | Scour Critical — Countermeasures Installed | Fair | 1930 | 3,712 |
| SCHLEGEL RUN | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1933 | 3,711 |
| N FK CROW RIVER | Minnesota | Scour Critical — Countermeasures Installed | Fair | 1941 | 3,710 |
| POHOPOCO CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1918 | 3,709 |
| ELLIS CREEK | New York | Scour Critical — Countermeasures Installed | Fair | 1931 | 3,708 |
| TRIB.TO MILL CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1932 | 3,704 |
| LONG BRANCH | Florida | Scour Critical — Countermeasures Installed | Fair | 1950 | 3,700 |
| MUZZLE FORK | West Virginia | Scour Critical — Countermeasures Installed | Poor | 1936 | 3,700 |
| PALMAS CREEK | Puerto Rico | Scour Critical — Countermeasures Installed | Fair | 1923 | 3,700 |
| CONOCOCHEAGUE CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1828 | 3,700 |
| SOUTH SALUDA RIVER | South Carolina | Scour Critical — Countermeasures Installed | Fair | 1970 | 3,700 |
| CREEK | Oklahoma | Scour Critical — Countermeasures Installed | Poor | 1950 | 3,700 |
| WARRIOR RIVER RELIEF | Alabama | Scour Critical — Countermeasures Installed | Fair | 1941 | 3,700 |
| WABASH RIVER | Illinois | Scour Critical — Countermeasures Installed | Fair | 1956 | 3,700 |
| BR OF UNAMI CREEK/2806G3 | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1951 | 3,699 |
| CHEWUCH RIVER | Washington | Scour Critical — Countermeasures Installed | Poor | 1961 | 3,696 |
| QUEMAHONING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Fair | 1949 | 3,695 |
| BRANCH POLSON CREEK | Indiana | Scour Critical — Countermeasures Installed | Fair | 1983 | 3,694 |
| NEWAUKUM CREEK | Washington | Scour Critical — Countermeasures Installed | Fair | 1927 | 3,694 |
| CHIPPEWA RIVER | Michigan | Scour Critical — Countermeasures Installed | Fair | 1961 | 3,694 |
| JONES CREEK | Michigan | Scour Critical — Countermeasures Installed | Fair | 1928 | 3,691 |
| BAYOU LACOMBE | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1953 | 3,690 |
| BOGUE FALAYA RELIEF | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1978 | 3,689 |
| PIGEON ROOST CREEK | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1980 | 3,689 |
| BOGUE FALAYA RIVER | Louisiana | Scour Critical — Countermeasures Installed | Fair | 1978 | 3,689 |
| Gila River | Arizona | Scour Critical — Countermeasures Installed | Good | 1988 | 3,688 |
| LITTLE CACOOSING CREEK | Pennsylvania | Scour Critical — Countermeasures Installed | Poor | 1942 | 3,682 |
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.