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
STONY RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1950 2,604
WINNIPESAUKEE RIVER New Hampshire Scour Critical — Countermeasures Installed Good 1988 2,602
W FK DRY WOOD CREEK Kansas Scour Critical — Countermeasures Installed Fair 1935 2,601
GOODBYS SWAMP South Carolina Scour Critical — Countermeasures Installed Fair 1938 2,600
WATERWAY Puerto Rico Scour Critical — Countermeasures Installed Fair 1930 2,600
SMYRE CREEK North Carolina Scour Critical — Countermeasures Installed Fair 1959 2,600
LITTLE SALMON RIVER Idaho Scour Critical — Countermeasures Installed Fair 1961 2,600
CARICOSA CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1921 2,600
FRANK AND POET DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1964 2,600
TRUCKEE RIVER Nevada Scour Critical — Countermeasures Installed Fair 1978 2,600
DRAW Colorado Scour Critical — Countermeasures Installed Poor 1938 2,600
LITTLE SALMON RIVER Idaho Scour Critical — Countermeasures Installed Fair 1962 2,600
LITTLE SALMON RIVER Idaho Scour Critical — Countermeasures Installed Fair 1962 2,600
CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1965 2,600
POCOTOPAUG CREEK Connecticut Scour Critical — Countermeasures Installed Fair 1929 2,600
OROCOVIS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1927 2,600
BURNT MILL CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1955 2,600
BEACON HILL BROOK Connecticut Scour Critical — Countermeasures Installed Good 1933 2,600
QUINEBAUG RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1931 2,600
FOUR HOLE SWAMP South Carolina Scour Critical — Countermeasures Installed Poor 1975 2,600
FOUR HOLE SWAMP South Carolina Scour Critical — Countermeasures Installed Fair 1975 2,600
LAPILE CREEK Arkansas Scour Critical — Countermeasures Installed Fair 1931 2,600
SCOTTS CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1975 2,600
EAST FORK WHITE RIVER Indiana Scour Critical — Countermeasures Installed Fair 1973 2,600
TRIB TO 18 MI.CREEK South Carolina Scour Critical — Countermeasures Installed Good 1980 2,600
GRANDE DE MANATI RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1978 2,600
LITTLE SALMON RIVER Idaho Scour Critical — Countermeasures Installed Fair 1962 2,600
PIGEON ROOST CR. Arkansas Scour Critical — Countermeasures Installed Fair 1958 2,600
BLACK RIVER Wisconsin Scour Critical — Countermeasures Installed Fair 1964 2,600
UNCOMPAHGRE RIVER Colorado Scour Critical — Countermeasures Installed Fair 1966 2,600
Creek Arkansas Scour Critical — Countermeasures Installed Fair 1928 2,600
GRANDE DE MAUNABO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1965 2,600
Clabber Creek Arkansas Scour Critical — Countermeasures Installed Poor 1939 2,600
BR BEAR CREEK Wisconsin Scour Critical — Countermeasures Installed Fair 1917 2,600
CAIN CREEK South Dakota Scour Critical — Countermeasures Installed Fair 1935 2,600
HOGANS CREEK North Carolina Scour Critical — Countermeasures Installed Poor 1967 2,600
MAYO RIVER North Carolina Scour Critical — Countermeasures Installed Poor 1965 2,600
SPRING CREEK Idaho Scour Critical — Countermeasures Installed Good 1962 2,600
N BR RARITAN RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1934 2,598
TRIB S BR PLUM CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1959 2,596
BRENT RUN Michigan Scour Critical — Countermeasures Installed Poor 1926 2,595
HARPETH RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1950 2,592
LITTLE INDIAN CREEK Indiana Scour Critical — Countermeasures Installed Fair 1966 2,590
BEAVER RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1920 2,589
FRIDAY HBR-SAN JUAN CHAN Washington Scour Critical — Countermeasures Installed Good 2005 2,587
ENGLISH CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1958 2,585
DEER CK South Dakota Scour Critical — Countermeasures Installed Fair 1967 2,585
SIPSEY RIVER RELIEF Alabama Scour Critical — Countermeasures Installed Fair 1956 2,582
SIPSEY RIVER Alabama Scour Critical — Countermeasures Installed Fair 1956 2,582
LITTLE THORNAPPLE RIVER Michigan Scour Critical — Countermeasures Installed Poor 1942 2,581

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.