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
CUTHAND CREEK BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1951 364
MULBERRY CR Texas Scour Critical — Countermeasures Ineffective Fair 1954 362
WILLACY MAIN CANAL Texas Scour Critical — Countermeasures Ineffective Fair 2007 358
DUCK CREEK Texas Scour Critical — Countermeasures Ineffective Good 1976 357
MAXWELL CREEK Texas Scour Critical — Countermeasures Ineffective Good 2003 356
MALLORY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1956 356
DUGAN CREEK Texas Scour Critical — Countermeasures Ineffective Good 1959 354
WEST YEGUA CREEK Texas Scour Critical — Countermeasures Ineffective Good 2024 353
CEDAR CREEK Georgia Scour Critical — Countermeasures Ineffective Good 2023 350
MOORES CREEK Alabama Scour Critical — Countermeasures Ineffective Poor 1910 350
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1967 350
MOUND CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1999 350
VALLEY FORK West Virginia Scour Critical — Countermeasures Ineffective Fair 1985 350
N SULPHUR RIVER Texas Scour Critical — Countermeasures Ineffective Good 2010 350
DRAW Texas Scour Critical — Countermeasures Ineffective Good 2008 347
ROCK CREEK RELIEF #1 Texas Scour Critical — Countermeasures Ineffective Fair 2001 345
DURHAM BR Texas Scour Critical — Countermeasures Ineffective Good 1951 345
MIDDLE SULPHUR RIVER Texas Scour Critical — Countermeasures Ineffective Good 2002 341
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1938 340
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1938 340
MORGAN BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1938 340
MUSTANG BAYOU Texas Scour Critical — Countermeasures Ineffective Good 2010 340
MALLORY CREEK Texas Scour Critical — Countermeasures Ineffective Good 2003 336
SHOOTER CR Texas Scour Critical — Countermeasures Ineffective Good 2006 332
CEDAR CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1985 330
CANEY CRK Texas Scour Critical — Countermeasures Ineffective Good 1967 330
DENTON CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1963 330
Loring Creek Relief Texas Scour Critical — Countermeasures Ineffective Fair 1949 329
BOIS DARC CRK Texas Scour Critical — Countermeasures Ineffective Good 1991 328
DRY FORK LITTLE WICHITA Texas Scour Critical — Countermeasures Ineffective Good 1964 328
KING CREEK Texas Scour Critical — Countermeasures Ineffective Good 1991 328
ALLEN CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1943 327
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1938 325
PARKER CREEK NO 2 Texas Scour Critical — Countermeasures Ineffective Good 1968 324
PARKERS CREEK Texas Scour Critical — Countermeasures Ineffective Good 1968 324
CYPRESS CREEK Texas Scour Critical — Countermeasures Ineffective Good 2013 320
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1972 320
N TONK BRANCH Texas Scour Critical — Countermeasures Ineffective Good 2008 318
CHIAMON CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Good 2004 316
ANDERSON CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1951 315
LAKE NOCONA SPILLWAY Texas Scour Critical — Countermeasures Ineffective Good 1997 313
HORSE CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1967 313
ALABAMA CREEK Texas Scour Critical — Countermeasures Ineffective Good 2022 312
PERSIMMON CREEK Texas Scour Critical — Countermeasures Ineffective Good 1997 310
ELM CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1966 310
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 2023 309
Drainage Ditch Texas Scour Critical — Countermeasures Ineffective Good 2023 309
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 2020 309
SALITRILLO CREEK Texas Scour Critical — Countermeasures Ineffective Good 2016 309
DENTON CREEK Texas Scour Critical — Countermeasures Ineffective Good 1966 309

Scour Critical Bridges by State

States ranked by number of scour critical bridges.

StateScour CriticalUnaddressedCountermeasuresIneffective
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 — UnaddressedBridge is scour critical with no countermeasures installed. The foundation is vulnerable and no protective action has been taken.
Code 3 — Countermeasures InstalledProtective measures (riprap, sheet piling, etc.) have been installed to reduce scour risk, but the bridge remains classified as scour critical.
Code 6 — Countermeasures IneffectiveProtective 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.