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
SILVER CREEK Indiana Scour Critical — Countermeasures Installed Good 1986 8,166
HARDY MILL CREEK Georgia Scour Critical — Countermeasures Installed Good 1971 8,160
WAWAYANDA CREEK New York Scour Critical — Countermeasures Installed Fair 1883 8,153
RED WASH California Scour Critical — Countermeasures Installed Good 1967 8,150
RED WASH California Scour Critical — Countermeasures Installed Good 1967 8,150
Deep Creek Oregon Scour Critical — Countermeasures Installed Fair 1948 8,140
AU SABLE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1960 8,126
AU SABLE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1960 8,125
SANDY RIVER Maine Scour Critical — Countermeasures Installed Fair 1958 8,124
LAFOURCHE BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1966 8,110
STEEP BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1955 8,105
CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1955 8,105
CHENIERE CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1955 8,105
KETTLE CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1925 8,101
ANIMAS RIVER Colorado Scour Critical — Countermeasures Installed Fair 1957 8,100
HOLLY DRAIN Michigan Scour Critical — Countermeasures Installed Good 1961 8,100
CAR SEAT CREEK Florida Scour Critical — Countermeasures Installed Fair 1924 8,100
STREAM Nebraska Scour Critical — Countermeasures Installed Good 1991 8,100
NEW PASS Florida Scour Critical — Countermeasures Installed Fair 1965 8,100
TAR RIVER North Carolina Scour Critical — Countermeasures Installed Fair 1982 8,100
Bear Creek Florida Scour Critical — Countermeasures Installed Good 1987 8,100
Colorado River Colorado Scour Critical — Countermeasures Installed Fair 1977 8,096
MT SCOTT CREEK Oregon Scour Critical — Countermeasures Installed Fair 2001 8,094
DRY FRIO RIVER Texas Scour Critical — Countermeasures Installed Fair 1931 8,093
FRIO RIVER Texas Scour Critical — Countermeasures Installed Fair 1931 8,093
LONG TOM RIVER Oregon Scour Critical — Countermeasures Installed Fair 1988 8,068
DEER CREEK Oregon Scour Critical — Countermeasures Installed Fair 1964 8,066
FRANKS BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1956 8,054
BRADDOCK CREEK Florida Scour Critical — Countermeasures Installed Fair 1924 8,050
ANDERSON CREEK Oregon Scour Critical — Countermeasures Installed Fair 1927 8,038
TURKEY CK Alabama Scour Critical — Countermeasures Installed Fair 1972 8,030
TURKEY CK Alabama Scour Critical — Countermeasures Installed Fair 1982 8,030
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1975 8,009
CHERRY RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 8,009
MANANTICO CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1929 8,007
PORTNEUF RIVER Idaho Scour Critical — Countermeasures Installed Fair 1963 8,000
MARK WEST CREEK California Scour Critical — Countermeasures Installed Poor 1958 8,000
HUNT RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1964 8,000
GUANAJIBO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1978 8,000
SOOS CREEK Washington Scour Critical — Countermeasures Installed Fair 1927 8,000
PORTNEUF RIVER Idaho Scour Critical — Countermeasures Installed Fair 1963 8,000
LITTLE BLACK CREEK Mississippi Scour Critical — Countermeasures Installed Good 1961 8,000
MEADOWBROOK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1963 8,000
LITTLE BLACK CREEK Mississippi Scour Critical — Countermeasures Installed Good 1961 8,000
INDIAN CREEK Idaho Scour Critical — Countermeasures Installed Good 1978 8,000
PINEY CREEK Tennessee Scour Critical — Countermeasures Installed Poor 1956 7,993
JACKSONBURG CREEK New Jersey Scour Critical — Countermeasures Installed Poor 1931 7,984
PAWTUXET RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1956 7,979
ELM FORK TRINITY RIVER Texas Scour Critical — Countermeasures Installed Good 1990 7,965
AMMONOOSUC RIVER New Hampshire Scour Critical — Countermeasures Installed Good 1950 7,962

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.