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 |
|---|---|---|---|---|---|
| HOLLIDAY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1995 | 4,525 |
| SIX MILE CREEK RELIEF | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 4,518 |
| SIX MILE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2007 | 4,518 |
| SOUTH CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2004 | 4,510 |
| ALLIGATOR CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2004 | 4,500 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1960 | 4,490 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1928 | 4,468 |
| BRANCH OF HOLLIDAY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 4,468 |
| GREENVIEW CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1942 | 4,461 |
| BUS77 UPRR & PRIMERA RD | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1967 | 4,457 |
| CEDAR CREEK (CANEY CRK) | Texas | Scour Critical — Countermeasures Ineffective | Good | 2006 | 4,455 |
| WOLF CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1957 | 4,454 |
| HORSE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1998 | 4,454 |
| LITTLE WOLF CRK. | Texas | Scour Critical — Countermeasures Ineffective | Good | 1957 | 4,454 |
| FORT EWELL CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1929 | 4,449 |
| LITTLE LAKE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1972 | 4,441 |
| MILLER BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1954 | 4,427 |
| Arroyo Dolores | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1937 | 4,424 |
| Arroyo Salado | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1935 | 4,424 |
| E FORK POST OAK CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1962 | 4,415 |
| E FORK POST OAK CRK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1981 | 4,415 |
| DEAN SWAMP | South Carolina | Scour Critical — Countermeasures Ineffective | Good | 2020 | 4,400 |
| SALMON BRANCH OVERFLOW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1925 | 4,396 |
| SALMON BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1925 | 4,396 |
| SALMON BRANCH OVERFLOW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1925 | 4,396 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1929 | 4,392 |
| HCWID #1 MASTER DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 1989 | 4,389 |
| SHAWNEE CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2016 | 4,382 |
| LAKE FORK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1978 | 4,367 |
| MENARD BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1954 | 4,358 |
| Pecan Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 1960 | 4,354 |
| SCATTER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2005 | 4,344 |
| TEN MILE CRK/MAUK BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1964 | 4,338 |
| L WICHITA SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1929 | 4,328 |
| ONION CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1929 | 4,328 |
| N FLOODWAY PILOT CHANNEL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1941 | 4,321 |
| Drainage Ditch | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 4,320 |
| JACK CREEK TRIBUTARY | Texas | Scour Critical — Countermeasures Ineffective | Good | 1939 | 4,312 |
| MCCOY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1999 | 4,311 |
| BRUTON CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1999 | 4,311 |
| BASSETTS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1931 | 4,311 |
| Mason Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 4,300 |
| Mason Creek | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1990 | 4,300 |
| CHAUMONT RIVER | New York | Scour Critical — Countermeasures Ineffective | Good | 2024 | 4,296 |
| MCGOWAN BROOK | Rhode Island | Scour Critical — Countermeasures Ineffective | Good | 2022 | 4,260 |
| HCFCD DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2001 | 4,250 |
| PLUM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1950 | 4,250 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1957 | 4,241 |
| MUSTANG BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1964 | 4,236 |
| TIMBER CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1969 | 4,205 |
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.