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
PETERSON CREEK Oregon Scour Critical — Countermeasures Installed Fair 1962 6,611
TUPPER RIVER Michigan Scour Critical — Countermeasures Installed Fair 1934 6,610
Sparkill Creek New York Scour Critical — Countermeasures Installed Poor 1955 6,609
MILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1936 6,605
RAMBIN BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1978 6,604
GILLS CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1972 6,600
COAL CREEK Colorado Scour Critical — Countermeasures Installed Fair 1921 6,600
MILL CREEK Oregon Scour Critical — Countermeasures Installed Fair 1965 6,600
GILDER CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1964 6,600
ROCKY RIVER North Carolina Scour Critical — Countermeasures Installed Fair 1971 6,600
SANTIAGO CHANNEL Puerto Rico Scour Critical — Countermeasures Installed Fair 1919 6,600
CANEY FORK Indiana Scour Critical — Countermeasures Installed Fair 1986 6,600
CEDAR CREEK Florida Scour Critical — Countermeasures Installed Fair 1947 6,600
MID-PRONG ST MARYS RIVER Florida Scour Critical — Countermeasures Installed Fair 1948 6,600
ARKANSAS RIVER TRIB. Oklahoma Scour Critical — Countermeasures Installed Poor 1980 6,598
PETERS RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1900 6,592
SUTHERLIN CREEK Oregon Scour Critical — Countermeasures Installed Fair 1921 6,589
GREENS BAYOU Texas Scour Critical — Countermeasures Installed Good 1995 6,587
GREENS BAYOU Texas Scour Critical — Countermeasures Installed Good 1995 6,587
BIG CREEK Louisiana Scour Critical — Countermeasures Installed Fair 2006 6,586
WALNUT RIVER OVERFLOW Kansas Scour Critical — Countermeasures Installed Good 1987 6,583
WALNUT RIVER Kansas Scour Critical — Countermeasures Installed Fair 1956 6,583
WILLOW RUN Michigan Scour Critical — Countermeasures Installed Poor 1928 6,582
BIG SABLE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1959 6,578
VIEJAS CREEK California Scour Critical — Countermeasures Installed Good 1933 6,575
HERSEY RIVER Michigan Scour Critical — Countermeasures Installed Fair 1958 6,569
PLEASANT BROOK New Jersey Scour Critical — Countermeasures Installed Good 1945 6,566
POMPESTON CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1970 6,554
WEST COLYELL CR Louisiana Scour Critical — Countermeasures Installed Fair 1952 6,554
HUMBOLDT RVR Nevada Scour Critical — Countermeasures Installed Fair 1986 6,550
MISS RIV/RR/MSS6000 Illinois Scour Critical — Countermeasures Installed Fair 1874 6,550
KLICKITAT CREEK Washington Scour Critical — Countermeasures Installed Good 1937 6,548
TOWNSENDS INLET New Jersey Scour Critical — Countermeasures Installed Poor 1939 6,548
SINGSING CREEK New York Scour Critical — Countermeasures Installed Fair 1924 6,547
Spring Draw Texas Scour Critical — Countermeasures Installed Fair 1960 6,541
WATER FORT RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1957 6,538
WILLAMETTE R/RIVER RD S Oregon Scour Critical — Countermeasures Installed Fair 1951 6,536
N FORK ASH CREEK Oregon Scour Critical — Countermeasures Installed Fair 1957 6,536
SANTA CLARA RIVER Utah Scour Critical — Countermeasures Installed Fair 1931 6,533
PINE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1961 6,532
PINE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1961 6,532
LONG TOM RIVER OVERFLOW Oregon Scour Critical — Countermeasures Installed Good 1988 6,530
PANTHER CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1902 6,528
MUSCONETCONG RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1925 6,520
WALLKILL RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1875 6,520
SO SABINE RIVER Texas Scour Critical — Countermeasures Installed Fair 1964 6,515
WALLKILL RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1910 6,513
LOANTAKA BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1936 6,512
HUMPTULIPS RIVER Washington Scour Critical — Countermeasures Installed Fair 1956 6,510
ARKANSAS RIVER Colorado Scour Critical — Countermeasures Installed Fair 1959 6,509

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.