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
SHELTON DITCH Oregon Scour Critical — Countermeasures Installed Fair 1959 3,278
BIG SANDY CREEK Texas Scour Critical — Countermeasures Installed Fair 2000 3,278
N FK LITTLE BUTTE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1968 3,276
CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1948 3,275
PATRICK CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1951 3,275
CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1948 3,275
CHOUDRANT CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1948 3,275
BROWNLEE CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1951 3,275
PASSAIC RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1929 3,268
BRANCH MILLERS RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1942 3,268
SANDY CR Missouri Scour Critical — Countermeasures Installed Fair 1940 3,266
ROW RIVER Oregon Scour Critical — Countermeasures Installed Fair 1969 3,263
SEALS GULLY Texas Scour Critical — Countermeasures Installed Fair 1979 3,261
SUGAR CREEK Indiana Scour Critical — Countermeasures Installed Fair 1965 3,260
CLEAR CREEK RELIEF Texas Scour Critical — Countermeasures Installed Fair 1952 3,256
SECRET RAVINE California Scour Critical — Countermeasures Installed Good 1970 3,256
TRAIL CREEK Oregon Scour Critical — Countermeasures Installed Fair 1958 3,256
LITTLE BLUE RIVER Indiana Scour Critical — Countermeasures Installed Good 1988 3,248
FLAT CREEK Indiana Scour Critical — Countermeasures Installed Fair 1926 3,248
KISTATOM CREEK New York Scour Critical — Countermeasures Installed Fair 1941 3,247
LINK RIVER Oregon Scour Critical — Countermeasures Installed Fair 1926 3,241
INTRACOASTAL WATERWAY Florida Scour Critical — Countermeasures Installed Fair 1969 3,240
WAHOO CREEK N FK TRIB Nebraska Scour Critical — Countermeasures Installed Fair 1924 3,240
CEDAR CREEK Michigan Scour Critical — Countermeasures Installed Fair 1964 3,239
MUD CREEK Arkansas Scour Critical — Countermeasures Installed Poor 1947 3,235
Blackland Gully Texas Scour Critical — Countermeasures Installed Good 1991 3,233
PAWNEE RIVER Kansas Scour Critical — Countermeasures Installed Fair 1953 3,232
SHIP HBR/GUEMES CHANNEL Washington Scour Critical — Countermeasures Installed Poor 1959 3,227
SHIP HBR/GUEMES CHANNEL Washington Scour Critical — Countermeasures Installed Fair 1971 3,227
CHARLESTON RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1935 3,221
DRY BRANCH Indiana Scour Critical — Countermeasures Installed Good 1976 3,220
PINCONNING RIVER Michigan Scour Critical — Countermeasures Installed Good 1995 3,218
E FORK BIRCH CREEK Oregon Scour Critical — Countermeasures Installed Fair 1940 3,218
N BRANCH FLINT RIVER Michigan Scour Critical — Countermeasures Installed Poor 1965 3,217
TRIB W BR CODORUS CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1940 3,216
Sebastian Inlet Florida Scour Critical — Countermeasures Installed Poor 1964 3,214
AROOSTOOK RIVER Maine Scour Critical — Countermeasures Installed Fair 1980 3,210
EAST COW CREEK Kansas Scour Critical — Countermeasures Installed Good 1986 3,207
EAST COW CREEK OVERFLOW Kansas Scour Critical — Countermeasures Installed Good 1986 3,207
BR ONTONAGON RIVER Michigan Scour Critical — Countermeasures Installed Fair 1953 3,202
N FK S LITTLEJOHNS CREEK California Scour Critical — Countermeasures Installed Good 1954 3,202
BLOOMING GROVE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1926 3,201
ROCKY CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1971 3,200
Ile Des Cannes Coulee Louisiana Scour Critical — Countermeasures Installed Fair 1992 3,200
MIDDLE CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1971 3,200
Canal 068 Florida Scour Critical — Countermeasures Installed Good 1952 3,200
SALMON FALLS CRK Nevada Scour Critical — Countermeasures Installed Fair 1933 3,200
TRIB TO MACHINE CK South Carolina Scour Critical — Countermeasures Installed Poor 1967 3,200
S.FK.COEUR DALENE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1978 3,200
EL CHORRO CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1925 3,200

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.