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
FIVE MILE CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1948 6,894
BUFFALO BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1957 6,892
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1992 6,857
ELAM BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1938 6,850
TWELVEPOLE CREEK West Virginia Scour Critical — Countermeasures Ineffective Poor 1971 6,800
LITTLE SUGAR CREEK Arkansas Scour Critical — Countermeasures Ineffective Good 2023 6,800
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1995 6,787
BOIS DARC CRK Texas Scour Critical — Countermeasures Ineffective Fair 1930 6,781
CUTHAND CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1950 6,781
WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1965 6,777
HALFWAY HILLS WASH California Scour Critical — Countermeasures Ineffective Fair 2024 6,750
DRAIN Texas Scour Critical — Countermeasures Ineffective Good 1984 6,727
OYSTER CREEK Texas Scour Critical — Countermeasures Ineffective Good 2012 6,724
BULLHEAD SLOUGH Texas Scour Critical — Countermeasures Ineffective Good 2012 6,724
OYSTER CREEK Texas Scour Critical — Countermeasures Ineffective Good 2012 6,684
BULLHEAD SLOUGH Texas Scour Critical — Countermeasures Ineffective Good 2012 6,684
PHELPS CREEK Texas Scour Critical — Countermeasures Ineffective Good 2009 6,682
MUSTANG CREEK Texas Scour Critical — Countermeasures Ineffective Good 1990 6,658
MILL CREEK Texas Scour Critical — Countermeasures Ineffective Good 2006 6,650
PINE CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1971 6,639
PINE CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1971 6,639
PINE CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1971 6,639
PINE CREEK DRAW Texas Scour Critical — Countermeasures Ineffective Good 1998 6,639
ARROYO COLORADO Texas Scour Critical — Countermeasures Ineffective Good 1993 6,619
SH 288 NB AND H SLOUGH Texas Scour Critical — Countermeasures Ineffective Good 2024 6,614
MEDINA RIVER Texas Scour Critical — Countermeasures Ineffective Good 1977 6,608
Trib 2 of Mound Crk Texas Scour Critical — Countermeasures Ineffective Good 2023 6,600
Trib 2 of Mound Crk Texas Scour Critical — Countermeasures Ineffective Good 2023 6,600
SALADO CREEK Texas Scour Critical — Countermeasures Ineffective Good 2016 6,584
LONG BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1934 6,578
NATURAL GROUND Texas Scour Critical — Countermeasures Ineffective Good 2011 6,570
DRAIN Texas Scour Critical — Countermeasures Ineffective Good 1938 6,563
DONNA MAIN CANAL Texas Scour Critical — Countermeasures Ineffective Fair 1949 6,554
IRON ORE CREEK Texas Scour Critical — Countermeasures Ineffective Good 1984 6,539
JONES CR Texas Scour Critical — Countermeasures Ineffective Fair 1922 6,515
JONES CR SLOUGH Texas Scour Critical — Countermeasures Ineffective Fair 1922 6,515
DONNA DRAIN Texas Scour Critical — Countermeasures Ineffective Fair 1967 6,513
S FORK OF CHACON CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1937 6,498
GLADE CREEK Texas Scour Critical — Countermeasures Ineffective Good 1950 6,493
POST OAK CREEK TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Fair 1962 6,470
LITTLE VINCE BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1980 6,470
LAKE RAY HUBBARD Texas Scour Critical — Countermeasures Ineffective Good 2024 6,460
LAKE RAY HUBBARD Texas Scour Critical — Countermeasures Ineffective Good 2024 6,460
ARMAND BAYOU TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Fair 1994 6,434
ARMAND BAYOU TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Fair 1979 6,434
FAULKEY GULLY Texas Scour Critical — Countermeasures Ineffective Good 1997 6,425
Trib of Willow Creek Texas Scour Critical — Countermeasures Ineffective Good 2021 6,407
Holder Branch Texas Scour Critical — Countermeasures Ineffective Good 2021 6,407
Willow Creek Texas Scour Critical — Countermeasures Ineffective Good 2021 6,407
Underwood Branch Texas Scour Critical — Countermeasures Ineffective Good 2021 6,407

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.