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
Trib 4 to Fairchilds Crk Texas Scour Critical — Countermeasures Ineffective Good 2023 8,661
Fairchilds Crk Trib 5 Texas Scour Critical — Countermeasures Ineffective Good 2024 8,661
LONG BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1948 8,630
NORTH FLOODWAY Texas Scour Critical — Countermeasures Ineffective Fair 1937 8,629
COOPER CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1955 8,621
KENNEDY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1932 8,614
KENNEDY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 8,614
BRANCH OF PECAN CREEK Texas Scour Critical — Countermeasures Ineffective Good 1934 8,600
TONKAWA CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1934 8,592
SAN BERNARD RIVER Texas Scour Critical — Countermeasures Ineffective Good 1996 8,564
STEWART CREEK TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Good 1996 8,550
N FORK BIG MINERAL CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1962 8,529
S FORK BIG MINERAL CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1962 8,529
BOIS DARC CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1958 8,509
BOIS DARC CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1958 8,509
PROVIDENCE CREEK South Carolina Scour Critical — Countermeasures Ineffective Good 2023 8,500
LITTLE WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Good 1961 8,450
MAIN FLOODWAY Texas Scour Critical — Countermeasures Ineffective Fair 2007 8,446
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1966 8,424
TUG FORK West Virginia Scour Critical — Countermeasures Ineffective Fair 1997 8,400
COOPER CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1921 8,393
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1989 8,364
Medio Creek Texas Scour Critical — Countermeasures Ineffective Good 2022 8,351
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1929 8,330
WATTERS CREEK Texas Scour Critical — Countermeasures Ineffective Good 1997 8,329
WATTERS CREEK Texas Scour Critical — Countermeasures Ineffective Good 2002 8,329
NORTH DITCH # 1 Texas Scour Critical — Countermeasures Ineffective Fair 1990 8,281
Two Mile Creek Alabama Scour Critical — Countermeasures Ineffective Good 2024 8,250
MCGEE GULLY Texas Scour Critical — Countermeasures Ineffective Good 1989 8,243
LITTLE VINCE BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1986 8,230
H.C. DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 2014 8,223
HURRICANE CREEK TRIB Texas Scour Critical — Countermeasures Ineffective Good 1938 8,141
DUNNS CR Texas Scour Critical — Countermeasures Ineffective Good 1958 8,108
POOR FARM DITCH Texas Scour Critical — Countermeasures Ineffective Good 2011 8,080
UPRR MARY AVE WACO CRK Texas Scour Critical — Countermeasures Ineffective Poor 1935 8,074
HONEY RUN CREEK Texas Scour Critical — Countermeasures Ineffective Good 1942 8,054
LAKE WOODLANDS Texas Scour Critical — Countermeasures Ineffective Good 2000 8,054
MAIN FLOODWAY PILOT CHAN Texas Scour Critical — Countermeasures Ineffective Good 2012 8,036
MULBERRY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1934 8,023
LITTLE SANDY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1934 8,023
ROWLETT CREEK BRANCH Texas Scour Critical — Countermeasures Ineffective Good 2009 8,015
STEWARTS CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1926 8,006
BR OF MOUND CRK Texas Scour Critical — Countermeasures Ineffective Good 1972 8,005
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 2006 8,000
LONG BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1966 8,000
HALFWAY HILLS WASH California Scour Critical — Countermeasures Ineffective Fair 2024 8,000
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 2011 7,999
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1986 7,990
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1985 7,990
ROWLETT CREEK Texas Scour Critical — Countermeasures Ineffective Good 1999 7,977

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.