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
Houston Ship Channel Texas Scour Critical — Countermeasures Ineffective Good 1930 1,903
CARTWRIGHT BRANCH West Virginia Scour Critical — Countermeasures Ineffective Good 1974 1,900
ROBINETTE BRANCH West Virginia Scour Critical — Countermeasures Ineffective Good 1974 1,900
GARY CREEK Texas Scour Critical — Countermeasures Ineffective Good 2024 1,900
TIMBER CREEK Texas Scour Critical — Countermeasures Ineffective Good 1984 1,898
RIO GRANDE RIVER Texas Scour Critical — Countermeasures Ineffective Fair 1979 1,895
HIDALGO W MAIN DRAIN Texas Scour Critical — Countermeasures Ineffective Fair 1989 1,888
RAYMONDVILLE DRAIN Texas Scour Critical — Countermeasures Ineffective Good 1969 1,883
WALNUT CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1940 1,880
FLINT CREEK Texas Scour Critical — Countermeasures Ineffective Good 1927 1,868
LITTLE VINCE BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1980 1,860
FARMERS BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1968 1,860
VINCE BAYOU Texas Scour Critical — Countermeasures Ineffective Good 1998 1,860
BLACKS CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 1,853
FISHER CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 1,853
LITTLE WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1951 1,850
WESLACO MAIN DRAIN Texas Scour Critical — Countermeasures Ineffective Fair 1960 1,844
N IRRIGATION CANAL Texas Scour Critical — Countermeasures Ineffective Fair 1942 1,816
RESACA DE LOS FRESNOS Texas Scour Critical — Countermeasures Ineffective Good 2001 1,800
SULPHUR RIVER Texas Scour Critical — Countermeasures Ineffective Fair 1973 1,797
SULPHUR RIV REL 2 Texas Scour Critical — Countermeasures Ineffective Fair 1973 1,797
MUSTANG CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1987 1,797
RICKETTS BRANCH Texas Scour Critical — Countermeasures Ineffective Poor 1970 1,791
China Ditch Washington Scour Critical — Countermeasures Ineffective Poor 2009 1,790
RIPLEY CRK Texas Scour Critical — Countermeasures Ineffective Fair 1936 1,779
LITTLE BEAR CREEK Wyoming Scour Critical — Countermeasures Ineffective Fair 2018 1,775
Brooks Branch Texas Scour Critical — Countermeasures Ineffective Fair 1981 1,774
FRIO RIVER Texas Scour Critical — Countermeasures Ineffective Good 2016 1,766
WILLOW FLATS Texas Scour Critical — Countermeasures Ineffective Good 2015 1,760
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1964 1,758
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1938 1,751
GUM CREEK Georgia Scour Critical — Countermeasures Ineffective Good 1957 1,750
PLUM CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1942 1,745
TANYARD CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1940 1,740
WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1940 1,740
CARROLL BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1940 1,740
BOGGS GULLY Texas Scour Critical — Countermeasures Ineffective Fair 2000 1,740
CIBOLO CREEK Texas Scour Critical — Countermeasures Ineffective Good 2002 1,737
PECAN CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 1,734
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1998 1,730
PECAN CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 1,730
MILL CREEK Texas Scour Critical — Countermeasures Ineffective Good 2005 1,729
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1966 1,728
Salt Creek Texas Scour Critical — Countermeasures Ineffective Fair 1930 1,711
Drainage Ditch Texas Scour Critical — Countermeasures Ineffective Fair 1930 1,711
ONION CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1928 1,704
DOGWOOD CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1928 1,704
IH10 EX-RP/WBFR/SH99SBFR Texas Scour Critical — Countermeasures Ineffective Good 2014 1,700
VOGEL CREEK Texas Scour Critical — Countermeasures Ineffective Good 2006 1,700
Draw Texas Scour Critical — Countermeasures Ineffective Good 2024 1,688

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.