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
WHITE RIVER Indiana Scour Critical — Countermeasures Installed Fair 1974 4,260
SANTA ISABEL CREEK Texas Scour Critical — Countermeasures Installed Good 2000 4,260
COOKS BROOK Maine Scour Critical — Countermeasures Installed Fair 1932 4,258
MARION DRAIN CANAL Washington Scour Critical — Countermeasures Installed Good 1931 4,257
ELDER CREEK California Scour Critical — Countermeasures Installed Fair 1966 4,257
EVANS CREEK Michigan Scour Critical — Countermeasures Installed Fair 1962 4,256
MILLERS BRANCH Indiana Scour Critical — Countermeasures Installed Fair 1931 4,256
BROOKSHIRE CREEK Texas Scour Critical — Countermeasures Installed Good 1988 4,254
NEWTOWN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1796 4,254
DRAIN Louisiana Scour Critical — Countermeasures Installed Fair 1951 4,251
BAYOU GRAND CANE Louisiana Scour Critical — Countermeasures Installed Fair 1951 4,251
B.GRAND CANE RLF Louisiana Scour Critical — Countermeasures Installed Fair 1951 4,251
SILVER CREEK Indiana Scour Critical — Countermeasures Installed Fair 1933 4,248
M BR PINE RIVER Michigan Scour Critical — Countermeasures Installed Poor 1952 4,242
Tumble Creek Oregon Scour Critical — Countermeasures Installed Fair 1949 4,241
FADES CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1932 4,241
MUD CREEK Indiana Scour Critical — Countermeasures Installed Fair 1981 4,240
SKINNER DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1978 4,238
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1978 4,238
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1978 4,238
SKINNER DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1978 4,238
SEQUATCHIE RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1980 4,237
QUAKAKE CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1927 4,225
SALT CREEK New Mexico Scour Critical — Countermeasures Installed Fair 1974 4,224
YELLOW RIVER Indiana Scour Critical — Countermeasures Installed Fair 1964 4,219
KENT RUN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1940 4,215
WATER SCORTON RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1926 4,214
SOUTH UMPQUA RIVER Oregon Scour Critical — Countermeasures Installed Fair 1989 4,214
PACHAUG RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1951 4,214
ARKANSAS RIVER Kansas Scour Critical — Countermeasures Installed Fair 1957 4,206
PINE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1932 4,202
ROCK RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1954 4,201
ABITA RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1983 4,200
ALAPAHA RIVER OVERFLOW Florida Scour Critical — Countermeasures Installed Fair 1922 4,200
BIMINI CANAL Florida Scour Critical — Countermeasures Installed Good 1960 4,200
DEPRESSION SMALL STREAM Puerto Rico Scour Critical — Countermeasures Installed Fair 1925 4,200
FOWLER SWITCH CANAL California Scour Critical — Countermeasures Installed Fair 1938 4,200
GUAYO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1961 4,200
BROCKWAY CREEK Wisconsin Scour Critical — Countermeasures Installed Fair 1932 4,200
YAMPA RIVER Colorado Scour Critical — Countermeasures Installed Fair 1967 4,200
ANON CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1922 4,200
MARICAO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1983 4,200
ROCK RIVER Illinois Scour Critical — Countermeasures Installed Poor 1966 4,200
MARIA BAYOU TRIB. #3 Louisiana Scour Critical — Countermeasures Installed Good 2011 4,200
KALAMAZOO RIVER Michigan Scour Critical — Countermeasures Installed Fair 1950 4,200
SWARTZ CREEK Michigan Scour Critical — Countermeasures Installed Fair 1969 4,200
SHEPAUG RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1950 4,200
ARENAS CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1933 4,200
HAMILTON CR South Carolina Scour Critical — Countermeasures Installed Poor 1957 4,200
WINOOSKI RIVER Vermont Scour Critical — Countermeasures Installed Fair 1902 4,200

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.