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
MAD RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1935 3,340
SUGAR CREEK Indiana Scour Critical — Countermeasures Installed Fair 1970 3,340
Mid. Fk. Coquille River Oregon Scour Critical — Countermeasures Installed Fair 1962 3,336
Mid. Fk. Coquille River Oregon Scour Critical — Countermeasures Installed Fair 1962 3,336
Mid. Fk. Coquille River Oregon Scour Critical — Countermeasures Installed Fair 1962 3,336
BALL CREEK Michigan Scour Critical — Countermeasures Installed Good 2003 3,332
NORTH FORK ASH CREEK Oregon Scour Critical — Countermeasures Installed Fair 1922 3,329
ALLOWAYS CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1952 3,326
LITTLE BULL CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1900 3,323
E.BR.BIG ELK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1970 3,323
FIVE MILE CREEK Texas Scour Critical — Countermeasures Installed Fair 1977 3,321
BEAR CREEK Texas Scour Critical — Countermeasures Installed Fair 1957 3,320
BRAZOS RIVER Texas Scour Critical — Countermeasures Installed Fair 1965 3,317
Clear Creek Oregon Scour Critical — Countermeasures Installed Fair 1931 3,317
ALABAMA RIVER REL. Alabama Scour Critical — Countermeasures Installed Fair 1983 3,316
ALABAMA RIVER REL. Alabama Scour Critical — Countermeasures Installed Fair 1983 3,316
ALABAMA RIVER REL. Alabama Scour Critical — Countermeasures Installed Fair 1983 3,316
ALABAMA RIVER Alabama Scour Critical — Countermeasures Installed Fair 1985 3,316
SILVER CREEK Oregon Scour Critical — Countermeasures Installed Fair 1929 3,310
CLARK CR Missouri Scour Critical — Countermeasures Installed Poor 1965 3,308
OVER WARREN RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1966 3,304
TITTABAWASSEE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1958 3,302
BEAVERDAM CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1969 3,300
FOUR MILE CREEK South Carolina Scour Critical — Countermeasures Installed Good 1990 3,300
SHANKLIN CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1968 3,300
FRANK AND POET DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1959 3,300
BRUSHY CREEK Mississippi Scour Critical — Countermeasures Installed Fair 1958 3,300
GUADIANA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1965 3,300
MENG CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1981 3,300
UNKNOWN CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1999 3,300
UNKNOWN CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1999 3,300
KANSAS RIVER & BNSF RR Kansas Scour Critical — Countermeasures Installed Fair 1964 3,300
CRIMS CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1939 3,300
DURHAM CREEK North Carolina Scour Critical — Countermeasures Installed Fair 1960 3,300
RUSSIAN RIVER - JIMTOWN California Scour Critical — Countermeasures Installed Fair 1949 3,300
LUMAHAI STRM Hawaii Scour Critical — Countermeasures Installed Fair 1968 3,300
WESTFIELD CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1936 3,300
OVER BR. OF BEAVER RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1951 3,299
W BR MIDDLE BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1964 3,299
PIDCOCK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 3,292
MILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1981 3,290
BAYOU MOREAU Louisiana Scour Critical — Countermeasures Installed Poor 1957 3,289
TIMMONS DITCH Indiana Scour Critical — Countermeasures Installed Fair 1936 3,288
HAWN CREEK Oregon Scour Critical — Countermeasures Installed Poor 1964 3,288
LITTLE PIPE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1933 3,287
OSAGE RVR Missouri Scour Critical — Countermeasures Installed Poor 1964 3,285
OVERFLOW DUCK RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1970 3,281
DUCK RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1970 3,281
PENNYPACK CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1883 3,280
INDIAN CREEK Indiana Scour Critical — Countermeasures Installed Good 1992 3,278

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.