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
CEDAR BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1922 4,959
MISTEQUAY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1932 4,958
TRIB OF MIDDLE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 4,947
NOOSENECK RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1924 4,944
COON BRANCH Louisiana Scour Critical — Countermeasures Installed Fair 1992 4,942
WEST SANDY CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1963 4,939
CHOCOLAY RIVER Michigan Scour Critical — Countermeasures Installed Fair 1954 4,934
TEN MILE CREEK Texas Scour Critical — Countermeasures Installed Good 1989 4,930
SANTIAGO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1918 4,923
TRIB NO BR MAHANTANGO CR Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 4,922
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1937 4,916
TRINITY RIVER RELIEF Texas Scour Critical — Countermeasures Installed Fair 1952 4,916
SPRING CK South Dakota Scour Critical — Countermeasures Installed Fair 1963 4,913
SPRING CK South Dakota Scour Critical — Countermeasures Installed Fair 1963 4,913
MARMATON RIVER Kansas Scour Critical — Countermeasures Installed Good 1967 4,910
MIDDLE BR ESCANABA RIVER Michigan Scour Critical — Countermeasures Installed Fair 1967 4,907
E BR ESCANABA RIVER Michigan Scour Critical — Countermeasures Installed Fair 1940 4,907
MISS RVR RR STREETS Minnesota Scour Critical — Countermeasures Installed Fair 1941 4,905
HORSE BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1971 4,905
MINISTER CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1933 4,902
GURABO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1984 4,900
QUINNIPIAC RIVER Connecticut Scour Critical — Countermeasures Installed Poor 1963 4,900
MAUNABO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1930 4,900
TURNER CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1989 4,900
EL CABRO CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1950 4,900
HOODS CREEK California Scour Critical — Countermeasures Installed Fair 1930 4,900
BR OF BIG ALLISON CR South Carolina Scour Critical — Countermeasures Installed Fair 1960 4,900
DUCK CREEK California Scour Critical — Countermeasures Installed Fair 1920 4,900
TURKEY CREEK Colorado Scour Critical — Countermeasures Installed Fair 1977 4,900
ARENAS CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1929 4,900
SUWANNEE RIVER RELIEF Florida Scour Critical — Countermeasures Installed Fair 1947 4,900
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1955 4,900
MACKS BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1970 4,896
DOE RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1932 4,881
WABASH RIVER Indiana Scour Critical — Countermeasures Installed Good 1975 4,878
JOHNSONS POND Rhode Island Scour Critical — Countermeasures Installed Fair 1934 4,870
PINEY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1923 4,865
SUGAR CREEK Indiana Scour Critical — Countermeasures Installed Fair 1932 4,852
Bogue Creek Alabama Scour Critical — Countermeasures Installed Fair 1928 4,850
SHAKER RUN Indiana Scour Critical — Countermeasures Installed Fair 1953 4,850
HEEIA STRM Hawaii Scour Critical — Countermeasures Installed Fair 1921 4,850
LAS TRAMPAS CREEK California Scour Critical — Countermeasures Installed Good 1978 4,840
PIPE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1935 4,839
POWELL BUTTE CANAL Oregon Scour Critical — Countermeasures Installed Fair 1954 4,833
SPARKILL CREEK New York Scour Critical — Countermeasures Installed Poor 1931 4,830
KEUKA LAKE OUTLET PEDES New York Scour Critical — Countermeasures Installed Good 1880 4,826
W FK NOOKACHAMPS CREEK Washington Scour Critical — Countermeasures Installed Good 1952 4,825
W.BR.COXES CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1963 4,824
BROKEN ARROW CREEK Alabama Scour Critical — Countermeasures Installed Fair 1948 4,820
MOORS CREEK Nebraska Scour Critical — Countermeasures Installed Fair 1931 4,815

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.