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
ROCKAWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1936 6,133
SALMON FALLS RIVER New Hampshire Scour Critical — Countermeasures Installed Poor 1950 6,132
RODDY BAYOU Louisiana Scour Critical — Countermeasures Installed Good 2007 6,131
E BR RED CEDAR RIV DRN Michigan Scour Critical — Countermeasures Installed Fair 1983 6,131
PERRY CREEK Iowa Scour Critical — Countermeasures Installed Fair 1978 6,129
JOHNS RIVER Washington Scour Critical — Countermeasures Installed Fair 1952 6,124
LITTLE SUGAR CREEK Indiana Scour Critical — Countermeasures Installed Fair 1956 6,122
WEST BR. OF NAAMAN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1974 6,120
RIFLE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1937 6,120
CLOVER CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1974 6,118
KINNICKINNIC RIVER Wisconsin Scour Critical — Countermeasures Installed Fair 1953 6,113
BEAVER BROOK New Hampshire Scour Critical — Countermeasures Installed Poor 1900 6,111
FOX RIVER Wisconsin Scour Critical — Countermeasures Installed Fair 1971 6,100
CIDRA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1973 6,100
WHITE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1928 6,100
PEACE RIVER Florida Scour Critical — Countermeasures Installed Good 1956 6,100
PEACE RIVER OVERFLOW Florida Scour Critical — Countermeasures Installed Fair 1956 6,100
W RIVER RD; MISS RIV Minnesota Scour Critical — Countermeasures Installed Fair 1923 6,100
CLAY HOLE CREEK Florida Scour Critical — Countermeasures Installed Fair 1932 6,100
ROSE CREEK Florida Scour Critical — Countermeasures Installed Fair 1932 6,100
NEDS BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1958 6,100
LITTLE CHICO CREEK California Scour Critical — Countermeasures Installed Fair 1982 6,096
BRANCH TACONY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1938 6,088
YAKIMA RIVER Washington Scour Critical — Countermeasures Installed Fair 1971 6,083
South Fork Quartz Creek Oregon Scour Critical — Countermeasures Installed Fair 1938 6,082
North Fork Quartz Creek Oregon Scour Critical — Countermeasures Installed Fair 1939 6,082
WATER MILL RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1926 6,078
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1960 6,075
PORTAGE BYU Missouri Scour Critical — Countermeasures Installed Fair 1928 6,067
HERON BAY Alabama Scour Critical — Countermeasures Installed Fair 1981 6,065
JAMES BRANCH Delaware Scour Critical — Countermeasures Installed Fair 1920 6,064
SAUK RIVER Michigan Scour Critical — Countermeasures Installed Good 1929 6,063
ARKANSAS RIVER Kansas Scour Critical — Countermeasures Installed Fair 1977 6,053
SPROGELS RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1990 6,050
SALADO CREEK Texas Scour Critical — Countermeasures Installed Fair 1937 6,045
Columbia River Oregon Scour Critical — Countermeasures Installed Fair 1962 6,042
ELK CREEK Oregon Scour Critical — Countermeasures Installed Fair 1967 6,041
BAD RV South Dakota Scour Critical — Countermeasures Installed Fair 1956 6,040
S FORK WILDCAT CREEK Indiana Scour Critical — Countermeasures Installed Good 1994 6,040
CACOOSING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1927 6,035
MISSISSIPPI RIVER; ST Minnesota Scour Critical — Countermeasures Installed Fair 1971 6,033
TRIB TO BEAVER CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 6,025
TRIBUTARY MIDDLE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 6,025
FOX BRANCH Louisiana Scour Critical — Countermeasures Installed Fair 1968 6,010
ST MARYS RIVER OVERFLOW Indiana Scour Critical — Countermeasures Installed Fair 1996 6,001
MAD RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1906 6,000
BLACK CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1967 6,000
VIVI RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1947 6,000
JOES CREEK Florida Scour Critical — Countermeasures Installed Good 1981 6,000
WARES CREEK Florida Scour Critical — Countermeasures Installed Fair 1963 6,000

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.