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 |
|---|---|---|---|---|---|
| PHARR-SAN JUAN MAIN CAN. | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2000 | 20,582 |
| SPRING CR REL | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1990 | 20,352 |
| SPRING CR | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1990 | 20,352 |
| STEWARTS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1936 | 20,302 |
| VINCE BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 2003 | 20,240 |
| CHOCTAW CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1963 | 20,079 |
| VINCE BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 1995 | 20,000 |
| WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1955 | 20,000 |
| WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1967 | 20,000 |
| ROCK CREEK RELIEF #1 | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1956 | 19,874 |
| BOWMAN BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1995 | 19,791 |
| PHARR-S.JUAN-MCALL. LATR | Texas | Scour Critical — Countermeasures Ineffective | Good | 1989 | 19,782 |
| BRIER CREEK TRIBUTARY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1977 | 19,691 |
| SHARPSTOWN DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1970 | 19,688 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1925 | 19,672 |
| Drainage Ditch | Texas | Scour Critical — Countermeasures Ineffective | Good | 1946 | 19,613 |
| INDIAN CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1932 | 19,574 |
| HACKNEY LAKE FLOODWAY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1974 | 19,545 |
| BENS BRANCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2006 | 19,520 |
| DRY CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1990 | 19,388 |
| HACKNEY LAKE FLOODWAY | Texas | Scour Critical — Countermeasures Ineffective | Good | 1978 | 19,337 |
| LITTLE CANEY CR | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1989 | 19,309 |
| STEWARTS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 1989 | 19,282 |
| DRAINAGE DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1978 | 19,270 |
| ARROYO GARCENO | Texas | Scour Critical — Countermeasures Ineffective | Good | 1955 | 19,164 |
| ELM SLOUGH | Texas | Scour Critical — Countermeasures Ineffective | Good | 1922 | 19,140 |
| Pittman Wash-South | Nevada | Scour Critical — Countermeasures Ineffective | Good | 2024 | 19,100 |
| LANGHAM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 19,100 |
| BEAR CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 19,100 |
| LANGHAM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 19,100 |
| BEAR CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 19,100 |
| CYPRESS CREEK | Texas | Scour Critical — Countermeasures Ineffective | Fair | 2013 | 19,100 |
| LANGHAM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 19,100 |
| LANGHAM CREEK | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 19,100 |
| Pittman Wash-Bermuda | Nevada | Scour Critical — Countermeasures Ineffective | Good | 2024 | 19,100 |
| Bear Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 19,100 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 1967 | 18,974 |
| TAYLOR BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Poor | 1969 | 18,841 |
| TAYLOR BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Poor | 1969 | 18,841 |
| INTRACOASTAL WATERWAY | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1974 | 18,777 |
| IH 10 / WHITE OAK BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1965 | 18,750 |
| DRAW | Texas | Scour Critical — Countermeasures Ineffective | Good | 2010 | 18,585 |
| SPRING CR | Texas | Scour Critical — Countermeasures Ineffective | Fair | 1990 | 18,544 |
| GUYANDOTTE RIVER | West Virginia | Scour Critical — Countermeasures Ineffective | Fair | 1995 | 18,500 |
| Brazos River | Texas | Scour Critical — Countermeasures Ineffective | Good | 2007 | 18,493 |
| LITTLE CEDAR BAYOU | Texas | Scour Critical — Countermeasures Ineffective | Good | 1982 | 18,450 |
| DITCH | Texas | Scour Critical — Countermeasures Ineffective | Good | 2013 | 18,442 |
| DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 1978 | 18,428 |
| HIDALGO MAIN DRAIN | Texas | Scour Critical — Countermeasures Ineffective | Good | 2000 | 18,328 |
| Hurricane Creek | Texas | Scour Critical — Countermeasures Ineffective | Good | 2024 | 18,298 |
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.