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
Canal 078 Florida Scour Critical — Countermeasures Installed Good 1950 3,400
WATER STONY BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1870 3,400
CRUCES RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1952 3,400
NORTH EDISTO RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1955 3,400
PLACIDO BAYOU Florida Scour Critical — Countermeasures Installed Fair 1965 3,400
SAMMY SWAMP South Carolina Scour Critical — Countermeasures Installed Fair 1937 3,400
Creek Florida Scour Critical — Countermeasures Installed Fair 1940 3,400
GREAT BROOK Vermont Scour Critical — Countermeasures Installed Fair 1932 3,400
GRANDE DE ARECIBO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1976 3,400
HUTCHINSON CREEK California Scour Critical — Countermeasures Installed Poor 1952 3,400
LYNCHES RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1961 3,400
NEUSE RIVER North Carolina Scour Critical — Countermeasures Installed Fair 1970 3,400
AMES CREEK Oregon Scour Critical — Countermeasures Installed Fair 1960 3,399
SOUTH POPLAR RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1913 3,392
TRIB. TO MAHONING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1921 3,388
E FORK TRINITY RIVER Texas Scour Critical — Countermeasures Installed Fair 1985 3,383
RAINY RIVER Michigan Scour Critical — Countermeasures Installed Fair 1954 3,382
OVER OIL CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1937 3,381
ANGELICA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1927 3,378
ANGELICA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1927 3,378
WALNUT RIVER Kansas Scour Critical — Countermeasures Installed Fair 1988 3,377
BNSF RR & RED OAK CRK Texas Scour Critical — Countermeasures Installed Fair 1987 3,377
TRINITY RIVER Texas Scour Critical — Countermeasures Installed Fair 1997 3,375
Fortuna Wash Arizona Scour Critical — Countermeasures Installed Fair 1933 3,375
MICHIGAMME RIVER Michigan Scour Critical — Countermeasures Installed Fair 1958 3,375
SEELEY DITCH Oregon Scour Critical — Countermeasures Installed Good 2006 3,373
MISSISSINEWA RIVER Indiana Scour Critical — Countermeasures Installed Poor 1966 3,370
MILL RACE Delaware Scour Critical — Countermeasures Installed Fair 1982 3,366
BREAKNECK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1978 3,365
AMITE R RELIEF Louisiana Scour Critical — Countermeasures Installed Fair 1955 3,362
LILLYS CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1955 3,362
LILLYS CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1955 3,362
OCHLOCKNEE RIVER O/F Georgia Scour Critical — Countermeasures Installed Good 1991 3,360
OCHLOCKNEE RIVER Georgia Scour Critical — Countermeasures Installed Good 1991 3,360
DRY BRANCH Indiana Scour Critical — Countermeasures Installed Good 1957 3,360
SWATARA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1934 3,359
POTTER POND CHANNEL Rhode Island Scour Critical — Countermeasures Installed Good 2002 3,358
PETERS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1915 3,356
DALTON RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1954 3,356
WIGGINS BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1953 3,354
Calapooia River Oregon Scour Critical — Countermeasures Installed Fair 1937 3,351
Creek Oregon Scour Critical — Countermeasures Installed Poor 1954 3,351
HOG CREEK Indiana Scour Critical — Countermeasures Installed Fair 1933 3,350
LITTLE WABASH RIVER Indiana Scour Critical — Countermeasures Installed Fair 1928 3,350
HALL CREEK California Scour Critical — Countermeasures Installed Fair 1914 3,348
PEQUONNOCK RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1916 3,343
BEAR BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1965 3,342
FRENCHTOWN BROOK Rhode Island Scour Critical — Countermeasures Installed Good 2012 3,341
MCCOYS CREEK Florida Scour Critical — Countermeasures Installed Fair 1965 3,341
MAD RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1935 3,340

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.