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
THORNAPPLE RIVER Michigan Scour Critical — Countermeasures Installed Good 1970 2,730
HUBBLE CR OVRFL Missouri Scour Critical — Countermeasures Installed Poor 1936 2,729
HUBBLE CR Missouri Scour Critical — Countermeasures Installed Poor 1936 2,729
Beaver Creek Oregon Scour Critical — Countermeasures Installed Fair 1966 2,725
Butler Wash Arizona Scour Critical — Countermeasures Installed Good 1961 2,725
GLADDENS RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1927 2,723
S F NINNESCAH RIVER Kansas Scour Critical — Countermeasures Installed Good 1988 2,720
Santa Cruz River Arizona Scour Critical — Countermeasures Installed Poor 1959 2,718
LITTLE BLUE RIVER Indiana Scour Critical — Countermeasures Installed Fair 1987 2,718
CUNNINGHAM CREEK Oregon Scour Critical — Countermeasures Installed Fair 2005 2,717
SPRING GULLY Texas Scour Critical — Countermeasures Installed Fair 1980 2,715
COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1964 2,715
COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1965 2,715
Beaver Creek Oregon Scour Critical — Countermeasures Installed Fair 1936 2,713
COWLITZ RIVER Washington Scour Critical — Countermeasures Installed Fair 1948 2,712
DAVIS CREEK Washington Scour Critical — Countermeasures Installed Good 1957 2,712
COWLITZ R OVERFLOW Washington Scour Critical — Countermeasures Installed Good 1958 2,712
Big Horn River Wyoming Scour Critical — Countermeasures Installed Fair 1957 2,711
BAYOU AMY Louisiana Scour Critical — Countermeasures Installed Poor 1968 2,711
SALT CREEK Oregon Scour Critical — Countermeasures Installed Poor 1965 2,706
ROBINSONS BRANCH RAH RIV New Jersey Scour Critical — Countermeasures Installed Fair 1930 2,706
CUYON RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1877 2,700
CUYON RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1877 2,700
PORTNEUF RIVER Idaho Scour Critical — Countermeasures Installed Good 1968 2,700
WATER IPSWICH RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1861 2,700
CEDAR DRAW Idaho Scour Critical — Countermeasures Installed Fair 1932 2,700
BR YELLOW RIVER Wisconsin Scour Critical — Countermeasures Installed Poor 1936 2,700
OTTER CREEK Wisconsin Scour Critical — Countermeasures Installed Fair 1920 2,700
MILL GUT TIDAL INLET Rhode Island Scour Critical — Countermeasures Installed Poor 1967 2,700
EAST FORK ARKANSAS RIVER Colorado Scour Critical — Countermeasures Installed Good 2008 2,700
WINHALL RIVER Vermont Scour Critical — Countermeasures Installed Fair 1936 2,700
ALAMEDA CREEK California Scour Critical — Countermeasures Installed Fair 1948 2,700
DEEP CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1930 2,700
BRANCH TO EDISTO RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1931 2,700
Turner River Florida Scour Critical — Countermeasures Installed Fair 1949 2,700
CORONACA CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1961 2,700
N FK SCAPPOOSE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1957 2,700
MEADOW CREEK South Carolina Scour Critical — Countermeasures Installed Poor 1960 2,700
MENG CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1969 2,700
CEDAR CREEK #1 South Carolina Scour Critical — Countermeasures Installed Fair 1982 2,700
TURKEY QUARTER CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1967 2,700
EIGHT MILE RIVER Connecticut Scour Critical — Countermeasures Installed Good 1986 2,700
BEAVERDAM CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1962 2,700
BIG BEAVERDAM CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1979 2,700
WEST BR. BANTAM RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1961 2,700
TRIB OF E BR CODORUS CR Pennsylvania Scour Critical — Countermeasures Installed Poor 1941 2,695
CHIPPEWANUCK CREEK Indiana Scour Critical — Countermeasures Installed Good 1993 2,691
FALL CREEK Indiana Scour Critical — Countermeasures Installed Good 1976 2,690
SAW MILL RIVER New York Scour Critical — Countermeasures Installed Poor 1902 2,690
COON CREEK Kansas Scour Critical — Countermeasures Installed Good 1986 2,688

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.