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
LITTLE SHAWNEE CRK Texas Scour Critical — Countermeasures Ineffective Good 1930 5,508
DILLARD CREEK Arkansas Scour Critical — Countermeasures Ineffective Fair 1970 5,500
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1990 5,478
Hackberry Creek Texas Scour Critical — Countermeasures Ineffective Fair 2000 5,453
Hackberry Creek Texas Scour Critical — Countermeasures Ineffective Fair 2000 5,453
EDINBURG MAIN CANAL Texas Scour Critical — Countermeasures Ineffective Fair 2014 5,451
BRAZOS RIVER RELIEF Texas Scour Critical — Countermeasures Ineffective Good 2023 5,432
BRAZOS RIVER RELIEF Texas Scour Critical — Countermeasures Ineffective Good 2023 5,432
BRAZOS RIVER RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 2023 5,432
BRAZOS RIVER RELIEF DRAW Texas Scour Critical — Countermeasures Ineffective Good 2023 5,432
Poindexter Branch Texas Scour Critical — Countermeasures Ineffective Good 2013 5,394
PALMETTO CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1983 5,388
ALDEN BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1994 5,375
ALDEN BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1997 5,375
DUCK CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1995 5,341
BRAYS BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1986 5,340
BRAYS BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1986 5,340
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1998 5,338
LAKE TAWAKONI Texas Scour Critical — Countermeasures Ineffective Good 2016 5,311
GUYANDOTTE RIVER West Virginia Scour Critical — Countermeasures Ineffective Fair 1971 5,300
COWLEECH FORK SABINE Texas Scour Critical — Countermeasures Ineffective Fair 1971 5,296
GRAVEYARD BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1955 5,290
BNSF/MTRLINK/EL TORO CRK California Scour Critical — Countermeasures Ineffective Good 2024 5,290
DONNA DRAIN Texas Scour Critical — Countermeasures Ineffective Good 1995 5,278
DRAINAGE DITCH 9A Texas Scour Critical — Countermeasures Ineffective Fair 1963 5,273
CIBOLO CREEK Texas Scour Critical — Countermeasures Ineffective Good 2013 5,252
CIBOLO CREEK Texas Scour Critical — Countermeasures Ineffective Good 2013 5,252
Drainage Ditch Texas Scour Critical — Countermeasures Ineffective Good 2023 5,238
Hog Bayou Texas Scour Critical — Countermeasures Ineffective Good 1965 5,224
BRAZOS RIVER RELIEF Texas Scour Critical — Countermeasures Ineffective Good 2023 5,214
WATER MINE BROOK Massachusetts Scour Critical — Countermeasures Ineffective Fair 1850 5,200
STONE DAM CREEK Arkansas Scour Critical — Countermeasures Ineffective Fair 1935 5,200
BRUSHY CREEK Texas Scour Critical — Countermeasures Ineffective Good 2001 5,196
RED BRANCH CREEK Texas Scour Critical — Countermeasures Ineffective Good 2001 5,196
JERNIGAN CREEK Texas Scour Critical — Countermeasures Ineffective Fair 2016 5,190
JERNIGAN CREEK RELIEF #2 Texas Scour Critical — Countermeasures Ineffective Good 2016 5,190
JERNIGAN CREEK RELIEF #1 Texas Scour Critical — Countermeasures Ineffective Good 2016 5,190
SMALL CREEK Texas Scour Critical — Countermeasures Ineffective Good 1928 5,188
JOHNS CREEK Texas Scour Critical — Countermeasures Ineffective Good 2016 5,168
DOCTORS CREEK Texas Scour Critical — Countermeasures Ineffective Good 2016 5,168
NORTH FLOODWAY CHANNEL Texas Scour Critical — Countermeasures Ineffective Good 2006 5,150
SOUTH NOLAN CREEK Texas Scour Critical — Countermeasures Ineffective Good 1961 5,150
Corpus Christi Ship Chan Texas Scour Critical — Countermeasures Ineffective Fair 2007 5,113
Corpus Christi Ship Chan Texas Scour Critical — Countermeasures Ineffective Fair 2002 5,113
Corpus Christi Ship Chan Texas Scour Critical — Countermeasures Ineffective Fair 2002 5,113
Corpus Christi Ship Chan Texas Scour Critical — Countermeasures Ineffective Fair 2002 5,113
CHOCTAW CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1999 5,101
CHOCTAW CREEK Texas Scour Critical — Countermeasures Ineffective Good 1999 5,101
BRAYS BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1951 5,100
BRAYS BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1951 5,100

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.