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
Intracoastal Waterway Florida Scour Critical — Countermeasures Installed Fair 1971 9,150
Intracoastal Waterway Florida Scour Critical — Countermeasures Installed Fair 1971 9,150
PEQUANNOCK RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1943 9,147
LAKE CREEK Texas Scour Critical — Countermeasures Installed Fair 1938 9,132
WOODBURY CREEK New York Scour Critical — Countermeasures Installed Fair 1937 9,130
FLINT RIVER Michigan Scour Critical — Countermeasures Installed Fair 1926 9,126
FACTORY CREEK Alabama Scour Critical — Countermeasures Installed Fair 1974 9,125
FACTORY CREEK (-) Alabama Scour Critical — Countermeasures Installed Fair 1974 9,125
BLACK RIVER Michigan Scour Critical — Countermeasures Installed Fair 1972 9,123
BLACK RIVER Michigan Scour Critical — Countermeasures Installed Fair 1972 9,123
BRANCH OF FRENCH CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1961 9,113
PLUM CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1912 9,112
BAYOU DORCHEAT Louisiana Scour Critical — Countermeasures Installed Poor 1954 9,109
HUBS BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1972 9,104
ROCKY SLOUGH Nevada Scour Critical — Countermeasures Installed Good 1987 9,100
KAUKONAHUA STRM Hawaii Scour Critical — Countermeasures Installed Good 1940 9,100
EAST FORK CARSON RIVER Nevada Scour Critical — Countermeasures Installed Fair 1981 9,100
CONNECTICUT RIVER Connecticut Scour Critical — Countermeasures Installed Poor 1913 9,100
PELICAN ISLAND CHAN Texas Scour Critical — Countermeasures Installed Poor 1960 9,100
LITTLE RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1933 9,100
LITTLE RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1933 9,100
CROCKERY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1953 9,100
CROCKERY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1961 9,100
QUINEBAUG RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1957 9,100
VACA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1958 9,100
HILLSBOROUGH RIVER Florida Scour Critical — Countermeasures Installed Fair 1959 9,100
10TH ST. @ BEAR CR. Oregon Scour Critical — Countermeasures Installed Fair 1960 9,097
SOUTH CREEK Washington Scour Critical — Countermeasures Installed Good 1947 9,080
COLUMBIA RIVER VANTAGE Washington Scour Critical — Countermeasures Installed Fair 1962 9,077
AUSTIN RUN Virginia Scour Critical — Countermeasures Installed Fair 1933 9,070
WATER FORT POND BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1900 9,069
SCOTLAND RUN New Jersey Scour Critical — Countermeasures Installed Fair 1970 9,068
DRAIN Louisiana Scour Critical — Countermeasures Installed Fair 1954 9,053
STONY BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1924 9,052
Rockaway River New Jersey Scour Critical — Countermeasures Installed Fair 1967 9,052
BUFFALO RIVER New York Scour Critical — Countermeasures Installed Poor 1952 9,043
NODAWAY RVR Missouri Scour Critical — Countermeasures Installed Fair 1966 9,040
ROCK RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1920 9,029
MOREAU RVR Missouri Scour Critical — Countermeasures Installed Fair 1978 9,027
WILLOW RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1934 9,021
CHESTER CREEK / 3694-J10 Pennsylvania Scour Critical — Countermeasures Installed Poor 1898 9,019
WATER WEWEANTIC RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1929 9,017
LACAMAS CREEK Washington Scour Critical — Countermeasures Installed Fair 1957 9,017
CROOKED OAK CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 2000 9,000
TANGIPAHOA RIVER Mississippi Scour Critical — Countermeasures Installed Fair 1960 9,000
PUGET SOUND @ EAGLE HRBR Washington Scour Critical — Countermeasures Installed Fair 1972 9,000
TANGIPAHOA RIVER Mississippi Scour Critical — Countermeasures Installed Fair 1960 9,000
ARENAS CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1939 9,000
GRANDE DE MANATI RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1955 9,000
BIG MEADOW DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1899 9,000

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.