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.

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.