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
BRANCH BUSSERON CREEK Indiana Scour Critical — Countermeasures Installed Fair 1965 5,399
KETTLE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1965 5,399
LITTLE SPOKANE RIVER Washington Scour Critical — Countermeasures Installed Fair 1953 5,394
MUNCIE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1973 5,393
CYPRESS CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1950 5,393
BULLOCK CREEK Michigan Scour Critical — Countermeasures Installed Good 2020 5,390
BROWNS CREEK New York Scour Critical — Countermeasures Installed Good 2014 5,389
LOOSAHATCHIE RIVER Tennessee Scour Critical — Countermeasures Installed Poor 1947 5,388
DIVERSION DITCH Michigan Scour Critical — Countermeasures Installed Fair 1946 5,387
SUNDAY LAKE OUTLET Michigan Scour Critical — Countermeasures Installed Fair 1947 5,387
MIDDLE CREEK Kansas Scour Critical — Countermeasures Installed Fair 1981 5,387
LONGS BRANCH Indiana Scour Critical — Countermeasures Installed Fair 1954 5,376
Bobbys Run New Jersey Scour Critical — Countermeasures Installed Good 1992 5,376
PARADISE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1957 5,372
BLACK BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1971 5,367
PERDIDO RIVER Alabama Scour Critical — Countermeasures Installed Fair 1951 5,361
HERMISTON DITCH Oregon Scour Critical — Countermeasures Installed Fair 1977 5,360
WATER MILL RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1850 5,357
CALAPOOIA RIVER Oregon Scour Critical — Countermeasures Installed Fair 1960 5,356
CLIFTON BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1953 5,350
BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1953 5,350
SALMON CREEK New York Scour Critical — Countermeasures Installed Fair 1948 5,348
BRANCH MILL CREEK Indiana Scour Critical — Countermeasures Installed Fair 1932 5,336
GASCONADE RVR Missouri Scour Critical — Countermeasures Installed Fair 1978 5,331
BAYOU DES CANNES Louisiana Scour Critical — Countermeasures Installed Fair 1967 5,328
BROOKS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1993 5,328
WINN CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1967 5,328
YOUNGS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1946 5,321
PINE RUN Michigan Scour Critical — Countermeasures Installed Fair 1929 5,320
DIAMOND CREEK Kansas Scour Critical — Countermeasures Installed Good 1975 5,315
IRON ORE CREEK Texas Scour Critical — Countermeasures Installed Good 1984 5,315
KENDALL CREEK Washington Scour Critical — Countermeasures Installed Fair 1964 5,312
CANE CREEK Tennessee Scour Critical — Countermeasures Installed Poor 1935 5,309
Willamina River Oregon Scour Critical — Countermeasures Installed Fair 1963 5,308
Rock Creek Oregon Scour Critical — Countermeasures Installed Fair 1986 5,304
Necarney Creek Oregon Scour Critical — Countermeasures Installed Fair 1937 5,300
SNAKE RIVER;NYSSA BRIDGE Idaho Scour Critical — Countermeasures Installed Fair 1957 5,300
ANON CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1971 5,300
CIBUCO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1949 5,300
MUDDY RVR Nevada Scour Critical — Countermeasures Installed Fair 1944 5,300
SANTIAGO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1918 5,300
EEL RIVER California Scour Critical — Countermeasures Installed Fair 1911 5,300
BIG FLAT BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1957 5,296
CHESTER CREEK / 3696-C10 Pennsylvania Scour Critical — Countermeasures Installed Fair 1850 5,295
SKANEATELES CREEK New York Scour Critical — Countermeasures Installed Good 1997 5,288
COWEEMAN RIVER Washington Scour Critical — Countermeasures Installed Fair 1961 5,285
CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1970 5,284
COLES BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1900 5,281
LAWTON CREEK Washington Scour Critical — Countermeasures Installed Good 1925 5,270
GRIFFIN CR/SO. STAGE RD. Oregon Scour Critical — Countermeasures Installed Fair 1941 5,270

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.