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
IRRIGATION CANAL Texas Scour Critical — Countermeasures Ineffective Fair 1949 10,162
PARKER CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1996 10,155
BRICKHOUSE GULLY Texas Scour Critical — Countermeasures Ineffective Good 1968 10,150
BUS77 UPRR & PRIMERA RD Texas Scour Critical — Countermeasures Ineffective Fair 1967 10,110
HICKORY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1980 10,098
PAINT CREEK Michigan Scour Critical — Countermeasures Ineffective Good 2024 10,078
PANTHER BRANCH Texas Scour Critical — Countermeasures Ineffective Good 2000 10,038
US 181 and Drainage Chan Texas Scour Critical — Countermeasures Ineffective Good 2023 10,017
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1993 10,000
RELIEF FOR CANAL Mississippi Scour Critical — Countermeasures Ineffective Fair 1976 10,000
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1990 10,000
WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1958 10,000
PANTHER BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1999 10,000
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1990 10,000
SIMS BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1989 10,000
WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1958 10,000
HUNTING BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1960 10,000
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1997 10,000
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1993 10,000
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1998 10,000
DRY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1987 9,959
GRAPEVINE CREEK Texas Scour Critical — Countermeasures Ineffective Good 2002 9,956
NEAL CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1950 9,954
BANITA CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1935 9,912
Seaborne Creek Texas Scour Critical — Countermeasures Ineffective Good 2015 9,900
MOUND CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1972 9,890
COUNTRY CLUB BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1950 9,800
PEACH CR & MARE BR Texas Scour Critical — Countermeasures Ineffective Good 2007 9,774
ARROYO COLORADO Texas Scour Critical — Countermeasures Ineffective Fair 1957 9,768
HALLS BAYOU Texas Scour Critical — Countermeasures Ineffective Good 2011 9,685
LEWIS CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1972 9,679
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1988 9,676
RAYMONDVILLE DRAIN Texas Scour Critical — Countermeasures Ineffective Fair 2014 9,649
RAYMONDVILLE DRAIN Texas Scour Critical — Countermeasures Ineffective Fair 2014 9,649
ARROYO LOS OLMOS Texas Scour Critical — Countermeasures Ineffective Fair 1954 9,622
PLUM CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1940 9,620
LK CONROE/W FK SN JAC RI Texas Scour Critical — Countermeasures Ineffective Fair 1972 9,618
BERESFORD CREEK South Carolina Scour Critical — Countermeasures Ineffective Good 2024 9,600
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1949 9,600
OCMULGEE RIVER Georgia Scour Critical — Countermeasures Ineffective Good 2023 9,600
PANTHER BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1992 9,560
DUCK CREEK Texas Scour Critical — Countermeasures Ineffective Good 1988 9,554
BEAR CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1968 9,549
WEST CADDO SLOUGH Texas Scour Critical — Countermeasures Ineffective Good 2000 9,542
RIO GRANDE RIVER Texas Scour Critical — Countermeasures Ineffective Fair 1994 9,525
MULBERRY CREEK BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1950 9,490
MULBERRY CREEK BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1950 9,490
CRYSTAL CREEK Texas Scour Critical — Countermeasures Ineffective Good 2010 9,461
DRY COMAL CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1938 9,457
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1961 9,454

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.