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
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 2003 1,408
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1971 1,408
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1999 1,402
TRIB OF LITTLE PINE CRK Texas Scour Critical — Countermeasures Ineffective Good 2004 1,402
Muddy Bayou Relief Arkansas Scour Critical — Countermeasures Ineffective Fair 1961 1,400
LAKE MURRAY South Carolina Scour Critical — Countermeasures Ineffective Fair 1971 1,400
COPPERAS MINE FORK West Virginia Scour Critical — Countermeasures Ineffective Fair 1993 1,400
MC GRATH CREEK Texas Scour Critical — Countermeasures Ineffective Good 1998 1,400
BRIER CREEK Texas Scour Critical — Countermeasures Ineffective Good 1990 1,398
BIG SANDY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1980 1,391
BIG SANDY CREEK REL Texas Scour Critical — Countermeasures Ineffective Good 1980 1,391
ECHOLS CREEK Texas Scour Critical — Countermeasures Ineffective Good 2000 1,391
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1996 1,388
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1996 1,388
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 2003 1,387
REDMOND BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1976 1,381
CEDAR CREEK Texas Scour Critical — Countermeasures Ineffective Good 1991 1,367
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1954 1,366
Buck Creek Texas Scour Critical — Countermeasures Ineffective Good 2012 1,366
DRAW Texas Scour Critical — Countermeasures Ineffective Good 2007 1,366
Drainage Ditch Texas Scour Critical — Countermeasures Ineffective Good 1930 1,364
DRAW Texas Scour Critical — Countermeasures Ineffective Good 2010 1,359
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 2003 1,355
DRAW Texas Scour Critical — Countermeasures Ineffective Good 2005 1,351
San Pedro Creek Texas Scour Critical — Countermeasures Ineffective Good 2023 1,350
BRAZOS RIVER DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1965 1,330
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1966 1,326
CAMERON CREEK Texas Scour Critical — Countermeasures Ineffective Good 1925 1,322
NO NAME CREEK Texas Scour Critical — Countermeasures Ineffective Good 2002 1,322
LITTLE BLANCO CREEK Texas Scour Critical — Countermeasures Ineffective Good 2002 1,322
CAMERON CREEK REL Texas Scour Critical — Countermeasures Ineffective Fair 1925 1,322
CAMERON CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1925 1,322
BRAZOS RIVER TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Fair 1977 1,321
CCWID #2 DITCH E Texas Scour Critical — Countermeasures Ineffective Good 2003 1,320
CIBOLO CREEK Texas Scour Critical — Countermeasures Ineffective Fair 2000 1,310
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1990 1,308
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1947 1,303
SR 396 & SPRR Nevada Scour Critical — Countermeasures Ineffective Fair 1981 1,300
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1993 1,294
LAKE FORK CRK Texas Scour Critical — Countermeasures Ineffective Good 1998 1,290
WATER UNNAMED STREAM Massachusetts Scour Critical — Countermeasures Ineffective Good 2009 1,285
SPRING BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1957 1,285
LITTLE BULLARD CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1924 1,283
BIG BULLARD CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1924 1,283
REDMOND BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1948 1,281
CONNER CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 1,278
ANTHONY BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1962 1,268
EAST CADDO CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1986 1,268
FEATHERSTONE CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1995 1,268
MOUNTAIN CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1960 1,256

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.