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
DRAW Texas Scour Critical — Countermeasures Installed Fair 1960 4,098
THREAD RIVER Michigan Scour Critical — Countermeasures Installed Poor 1928 4,097
SPRING RIVER Kansas Scour Critical — Countermeasures Installed Good 1964 4,096
WEST KEMPF CREEK Texas Scour Critical — Countermeasures Installed Good 1979 4,093
Dry Wash Arizona Scour Critical — Countermeasures Installed Fair 1933 4,083
BIG INDIAN CREEK Georgia Scour Critical — Countermeasures Installed Good 1971 4,080
COULEE Louisiana Scour Critical — Countermeasures Installed Fair 1972 4,080
DRIFTWOOD RIVER Indiana Scour Critical — Countermeasures Installed Fair 1959 4,080
TRIB TO ROCKAWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1900 4,079
LOCAL DRAINAGE Colorado Scour Critical — Countermeasures Installed Good 2018 4,074
TICKFAW RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1962 4,071
Dry Creek Alabama Scour Critical — Countermeasures Installed Fair 1940 4,070
REEVES DITCH Indiana Scour Critical — Countermeasures Installed Fair 1996 4,070
SKUNK CK South Dakota Scour Critical — Countermeasures Installed Fair 1986 4,068
N FK NOOKSACK RIVER Washington Scour Critical — Countermeasures Installed Fair 1954 4,066
TRIB NO BR MAHANTANGO CR Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 4,066
THOMAS CREEK Oregon Scour Critical — Countermeasures Installed Fair 1961 4,066
BULL CK South Dakota Scour Critical — Countermeasures Installed Fair 1964 4,065
BULL CK South Dakota Scour Critical — Countermeasures Installed Fair 1964 4,065
TUTUILLA CREEK Oregon Scour Critical — Countermeasures Installed Fair 1988 4,062
NO CR Missouri Scour Critical — Countermeasures Installed Fair 1977 4,053
CANEY BAYOU REL Louisiana Scour Critical — Countermeasures Installed Poor 1957 4,051
SHEBOYGAN RIVER Wisconsin Scour Critical — Countermeasures Installed Fair 1957 4,050
LITTLE PORTAGE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1929 4,050
HUNLOCK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1925 4,044
CHEHALIS RIVER Washington Scour Critical — Countermeasures Installed Fair 1958 4,044
N BR BERMUDIAN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 4,044
DARBY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1922 4,029
I-465 WB LICK CREEK Indiana Scour Critical — Countermeasures Installed Fair 1962 4,028
SOL DUC RIVER Washington Scour Critical — Countermeasures Installed Fair 1958 4,018
BULL CREEK BNSF RR Kansas Scour Critical — Countermeasures Installed Fair 1964 4,016
REDWOOD CREEK Indiana Scour Critical — Countermeasures Installed Fair 1976 4,014
REDWOOD CREEK Indiana Scour Critical — Countermeasures Installed Good 1976 4,014
SILVER CREEK Indiana Scour Critical — Countermeasures Installed Fair 1937 4,014
KUSSHI CR Washington Scour Critical — Countermeasures Installed Poor 1945 4,013
CEDAR CREEK Washington Scour Critical — Countermeasures Installed Good 1958 4,008
Marys River Oregon Scour Critical — Countermeasures Installed Fair 1949 4,008
CHELATCHIE CREEK Washington Scour Critical — Countermeasures Installed Good 1953 4,008
YELLOWSTONE RIVER 170 Montana Scour Critical — Countermeasures Installed Poor 1949 4,005
FOUNTAIN CREEK Colorado Scour Critical — Countermeasures Installed Fair 1964 4,005
INDIAN CREEK Colorado Scour Critical — Countermeasures Installed Fair 1959 4,000
DRY CREEK CANAL California Scour Critical — Countermeasures Installed Fair 1941 4,000
JUAN MARTIN RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1916 4,000
FURNACE BROOK New York Scour Critical — Countermeasures Installed Fair 1948 4,000
W BRANCH SAUGATUCK RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1957 4,000
FOWLER SWITCH CANAL California Scour Critical — Countermeasures Installed Fair 1912 4,000
SPRING CREEK Texas Scour Critical — Countermeasures Installed Good 1989 4,000
Hogskin Lake Creek Louisiana Scour Critical — Countermeasures Installed Fair 1989 4,000
WILLAMETTE R COAST FK Oregon Scour Critical — Countermeasures Installed Fair 1967 4,000
MANCOS RIVER Colorado Scour Critical — Countermeasures Installed Fair 1959 4,000

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.