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
HCFCD DITCH Texas Scour Critical — Countermeasures Installed Fair 1979 9,939
SO. BRANCH RUSSIA BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1951 9,929
WASHOUGAL RIVER Washington Scour Critical — Countermeasures Installed Fair 1947 9,924
STONY CREEK / 3255-J5 Pennsylvania Scour Critical — Countermeasures Installed Fair 1933 9,921
DUNCAN CREEK Wisconsin Scour Critical — Countermeasures Installed Poor 1949 9,920
N. Branch of Canoe Brook New Jersey Scour Critical — Countermeasures Installed Good 1956 9,908
CANARY DITCH Indiana Scour Critical — Countermeasures Installed Fair 2000 9,905
NAUGATUCK RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1958 9,900
CLEMS BRANCH South Carolina Scour Critical — Countermeasures Installed Fair 1974 9,900
Sweetwater Creek Florida Scour Critical — Countermeasures Installed Good 1965 9,900
CEDRO CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1953 9,900
SPRING BROOK Wisconsin Scour Critical — Countermeasures Installed Fair 1968 9,900
BRANCH NESHAMINY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1936 9,883
SPRINGERS BROOK New Jersey Scour Critical — Countermeasures Installed Poor 1929 9,860
BRANCH OF PENNYPACK CRK Pennsylvania Scour Critical — Countermeasures Installed Poor 1958 9,860
ROCKY SLOUGH Nevada Scour Critical — Countermeasures Installed Good 1957 9,850
ELIZABETH RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1968 9,847
ST MARYS RIVER Indiana Scour Critical — Countermeasures Installed Fair 1969 9,815
POST OAK CREEK Texas Scour Critical — Countermeasures Installed Fair 1930 9,804
Slough Oregon Scour Critical — Countermeasures Installed Fair 1974 9,803
BEAVER CREEK Colorado Scour Critical — Countermeasures Installed Fair 1949 9,800
SOUTH FORK CATAWBA RIVER North Carolina Scour Critical — Countermeasures Installed Fair 1977 9,800
MULLET RIVER Wisconsin Scour Critical — Countermeasures Installed Good 1976 9,800
TUCKASEGEE RIVER North Carolina Scour Critical — Countermeasures Installed Fair 1969 9,800
LITTLE TALLAPOOSA RIVER Georgia Scour Critical — Countermeasures Installed Fair 1971 9,800
BURLINGTON BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1961 9,800
UNNAMED CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1950 9,800
WHITEWATER RIVER Kansas Scour Critical — Countermeasures Installed Fair 1955 9,799
DRY CREEK Kansas Scour Critical — Countermeasures Installed Good 1960 9,799
WHITEWATER RIVER Kansas Scour Critical — Countermeasures Installed Fair 1957 9,799
DRY CREEK Kansas Scour Critical — Countermeasures Installed Good 1955 9,799
FERDUN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1956 9,785
BIG RVR Missouri Scour Critical — Countermeasures Installed Fair 1977 9,781
Illinios Bayou Arkansas Scour Critical — Countermeasures Installed Fair 1964 9,777
QUANTUCK CREEK New York Scour Critical — Countermeasures Installed Fair 1941 9,775
E BR AU SABLE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1961 9,772
MOSHASSUCK RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1967 9,765
SNAKE RIVER;KING HILL Idaho Scour Critical — Countermeasures Installed Fair 1974 9,750
RD;UPRR;SNAKE R;GLENNS F Idaho Scour Critical — Countermeasures Installed Fair 1974 9,750
SNAKE RIVER;KING HILL Idaho Scour Critical — Countermeasures Installed Fair 1974 9,750
RD;UPRR;SNAKE R;GLENNS F Idaho Scour Critical — Countermeasures Installed Fair 1974 9,750
MID COLYELL CR. Louisiana Scour Critical — Countermeasures Installed Fair 1932 9,745
TR.LAUREL CK Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 9,745
MOREAU RVR Missouri Scour Critical — Countermeasures Installed Poor 1960 9,742
SNOQUALMIE RIVER Washington Scour Critical — Countermeasures Installed Poor 1931 9,740
GALLATIN RIVER Montana Scour Critical — Countermeasures Installed Fair 1965 9,726
GALLATIN RIVER Montana Scour Critical — Countermeasures Installed Fair 1965 9,726
PUGET SOUND @ FAUNTLEROY Washington Scour Critical — Countermeasures Installed Good 1984 9,721
PUGET SOUND @ FAUNTLEROY Washington Scour Critical — Countermeasures Installed Fair 1957 9,721
BACK SWAMP South Carolina Scour Critical — Countermeasures Installed Fair 1931 9,700

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.