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
QUAKER BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1957 2,900
WATERWAY Puerto Rico Scour Critical — Countermeasures Installed Fair 1969 2,900
CARR BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1938 2,900
KENAI RIVER (SCHOONERS) Alaska Scour Critical — Countermeasures Installed Fair 1954 2,900
SWIFT RIVER New Hampshire Scour Critical — Countermeasures Installed Fair 1975 2,900
APPLE CREEK North Dakota Scour Critical — Countermeasures Installed Fair 1914 2,900
SURVEYOR CREEK Colorado Scour Critical — Countermeasures Installed Fair 1935 2,900
BUCKHEAD CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1931 2,900
BUTLER DITCH Wisconsin Scour Critical — Countermeasures Installed Fair 1924 2,900
NORTH LABOVE BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 2013 2,899
VALLEY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1912 2,897
POPLAR CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
BEAR CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1949 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1951 2,897
BUCK RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1926 2,896
CREEK Louisiana Scour Critical — Countermeasures Installed Poor 1960 2,894
FERN CREEK Oregon Scour Critical — Countermeasures Installed Fair 1964 2,893
TAPPAN LAKE New York Scour Critical — Countermeasures Installed Fair 1967 2,892
SUMNER BROOK Connecticut Scour Critical — Countermeasures Installed Poor 1920 2,892
BELLDEAU BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1973 2,890
BAYOU DEVIEW Arkansas Scour Critical — Countermeasures Installed Fair 1956 2,889
TRIB TO PENNS CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1934 2,889
HOSENSACK CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1933 2,882
MIDDLE FK COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1983 2,879
MIDDLE FK COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1984 2,879
MIDDLE FK COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Good 1984 2,879
MIDDLE FK COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Good 1984 2,879
HOLMES CREEK Oregon Scour Critical — Countermeasures Installed Fair 1984 2,879
MIDDLE FK COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1984 2,879
COQUILLE RIVER MIDDLE FK Oregon Scour Critical — Countermeasures Installed Fair 1976 2,879
MIDDLE FK COQUILLE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1976 2,879
MENOMINEE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1966 2,875
WEST BRANCH CROTON RIVER New York Scour Critical — Countermeasures Installed Fair 1929 2,874
SHOAL CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1973 2,874
NISQUALLY R OVERFLOW Washington Scour Critical — Countermeasures Installed Good 1945 2,872
JUMPOFF JOE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1940 2,871
LONGS BRANCH Indiana Scour Critical — Countermeasures Installed Good 1955 2,870
KAWKAWLIN RIVER Michigan Scour Critical — Countermeasures Installed Fair 1987 2,870
Parc Perdu Bayou Louisiana Scour Critical — Countermeasures Installed Fair 1960 2,868
Parc Perdu Bayou Louisiana Scour Critical — Countermeasures Installed Fair 1960 2,868
E CANADA CREEK New York Scour Critical — Countermeasures Installed Poor 1931 2,866

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.