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
VAN BRUNT CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1940 6,398
YELLOWSTONE RIVER Montana Scour Critical — Countermeasures Installed Fair 1962 6,397
YELLOWSTONE RIVER Montana Scour Critical — Countermeasures Installed Fair 1962 6,397
Nehalem River Oregon Scour Critical — Countermeasures Installed Fair 1940 6,383
Wolf Creek Oregon Scour Critical — Countermeasures Installed Fair 1938 6,383
CHENIERE CREEK Louisiana Scour Critical — Countermeasures Installed Fair 2000 6,382
S. FK. FORKED DEER RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1931 6,381
JACKS CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1931 6,381
FLATROCK RIVER Indiana Scour Critical — Countermeasures Installed Fair 1983 6,380
KIMBERLIN CREEK Indiana Scour Critical — Countermeasures Installed Fair 1924 6,375
JORDAN CREEK Indiana Scour Critical — Countermeasures Installed Fair 1933 6,373
SCULLS CREEK Georgia Scour Critical — Countermeasures Installed Good 1960 6,370
RICHARDSON CREEK Georgia Scour Critical — Countermeasures Installed Good 2006 6,370
AQUETONG CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1959 6,360
CROOKED OAK CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1950 6,350
BRANCH MONTOUR RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1948 6,349
BRANCH OF MONTOUR RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1948 6,349
SAW MILL RUN STREAM Pennsylvania Scour Critical — Countermeasures Installed Fair 1920 6,348
Abiqua Creek Oregon Scour Critical — Countermeasures Installed Poor 1934 6,347
PANTHER CREEK Oregon Scour Critical — Countermeasures Installed Fair 1958 6,338
COBBS CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1906 6,335
FLINT RIVER Michigan Scour Critical — Countermeasures Installed Fair 1965 6,331
MARIA CREEK Indiana Scour Critical — Countermeasures Installed Fair 1971 6,328
MARIA CREEK Indiana Scour Critical — Countermeasures Installed Fair 1971 6,328
Verde River Arizona Scour Critical — Countermeasures Installed Fair 1975 6,328
22 MI RD & PARIS CREEK Michigan Scour Critical — Countermeasures Installed Fair 1984 6,322
22 MI RD & PARIS CREEK Michigan Scour Critical — Countermeasures Installed Fair 1984 6,322
WILLAMETTE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1955 6,321
Canal C-103 Mowry Florida Scour Critical — Countermeasures Installed Fair 1966 6,320
South Fork Rock Creek Oregon Scour Critical — Countermeasures Installed Fair 1975 6,320
SCHUYLKILL RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1916 6,319
BAYOU CASTOR Louisiana Scour Critical — Countermeasures Installed Poor 1951 6,314
IH30 & Trinity River RR Texas Scour Critical — Countermeasures Installed Fair 1911 6,304
CRETE CANAL Florida Scour Critical — Countermeasures Installed Good 1975 6,300
CUDDY CREEK California Scour Critical — Countermeasures Installed Fair 1970 6,300
THREE & TWENTY CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1949 6,300
LAJAS CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1939 6,300
HOLSTON CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1931 6,300
JACAGUAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1970 6,300
BERRACO CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1940 6,300
GUAYABOTA CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1940 6,300
RICKETTS BRANCH Texas Scour Critical — Countermeasures Installed Good 1987 6,294
RICKETTS BRANCH Texas Scour Critical — Countermeasures Installed Fair 1987 6,294
THORNAPPLE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1967 6,293
ABRAHAMS CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1962 6,292
Crow Creek Oregon Scour Critical — Countermeasures Installed Fair 1921 6,255
MISS RIV/FAU 9416 Illinois Scour Critical — Countermeasures Installed Poor 1942 6,250
PONCHATOULA CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1956 6,250
S.FK.COEUR DALENE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1969 6,250
S.FK.COEUR DALENE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1969 6,250

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.