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
BRUSH CREEK Oregon Scour Critical — Countermeasures Installed Fair 1955 2,681
BEAR TRAP CREEK Oregon Scour Critical — Countermeasures Installed Fair 1955 2,681
POWELL CREEK Florida Scour Critical — Countermeasures Installed Good 1985 2,680
WILSON CREEK California Scour Critical — Countermeasures Installed Good 1927 2,678
YAKIMA RIVER Washington Scour Critical — Countermeasures Installed Fair 1947 2,678
BLACK CREEK New York Scour Critical — Countermeasures Installed Fair 1929 2,675
Howell Creek Florida Scour Critical — Countermeasures Installed Good 1981 2,670
OVER MARSH CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1925 2,670
SIPSEY RIVER RELIEF Alabama Scour Critical — Countermeasures Installed Fair 1956 2,667
FULTON CREEK Washington Scour Critical — Countermeasures Installed Fair 1926 2,667
LAKE CR Washington Scour Critical — Countermeasures Installed Fair 1963 2,666
PEMIGEWASSET RIVER NHRR New Hampshire Scour Critical — Countermeasures Installed Fair 1937 2,666
TWENTYTWO CREEK Washington Scour Critical — Countermeasures Installed Fair 1952 2,662
MAHANTANGO CREEK Pennsylvania Scour Critical — Countermeasures Installed Good 1930 2,660
LACKAWANNA RIVER Pennsylvania Scour Critical — Countermeasures Installed Poor 1961 2,658
EVANS CREEK Michigan Scour Critical — Countermeasures Installed Poor 1934 2,657
E BR BIG CREEK Michigan Scour Critical — Countermeasures Installed Fair 1960 2,656
JOHNSON CR Washington Scour Critical — Countermeasures Installed Fair 1962 2,655
HUNTER WASH New Mexico Scour Critical — Countermeasures Installed Good 1984 2,653
WARD CREEK Oregon Scour Critical — Countermeasures Installed Fair 1984 2,652
FIVE MILE CREEK Texas Scour Critical — Countermeasures Installed Fair 1970 2,650
NINE MILE CREEK Kansas Scour Critical — Countermeasures Installed Fair 1978 2,650
ELK CREEK Oregon Scour Critical — Countermeasures Installed Fair 1957 2,644
CANEY CREEK Louisiana Scour Critical — Countermeasures Installed Poor 1954 2,642
LAMPREY RIVER New Hampshire Scour Critical — Countermeasures Installed Fair 1932 2,642
BEAVER CREEK REL. Alabama Scour Critical — Countermeasures Installed Fair 1976 2,640
SOL SHANK DITCH Indiana Scour Critical — Countermeasures Installed Fair 1988 2,639
PUGET SOUND Washington Scour Critical — Countermeasures Installed Fair 1993 2,635
ABIQUA CREEK Oregon Scour Critical — Countermeasures Installed Fair 1954 2,635
CHAPEPEELA CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1957 2,634
CHAP CREEK RELIEF Louisiana Scour Critical — Countermeasures Installed Fair 1957 2,634
WALNUT FORK Indiana Scour Critical — Countermeasures Installed Fair 1953 2,630
SYCAMORE CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1960 2,630
EAST BRANCH SALMON BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1937 2,630
JESTER CREEK Kansas Scour Critical — Countermeasures Installed Good 1987 2,627
ONION CREEK Kansas Scour Critical — Countermeasures Installed Fair 1970 2,627
ONION CREEK Kansas Scour Critical — Countermeasures Installed Good 1970 2,627
FLAT RIVER Louisiana Scour Critical — Countermeasures Installed Poor 1964 2,626
BERG SLOUGH Washington Scour Critical — Countermeasures Installed Poor 1964 2,622
LOSTINE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1953 2,619
WOLF RIVER Kansas Scour Critical — Countermeasures Installed Fair 1965 2,619
LITTLE PAINT CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1947 2,617
ROYCE BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1978 2,617
MOSHER CREEK Wisconsin Scour Critical — Countermeasures Installed Fair 1950 2,616
FRANKS. BR.JUNIATA RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1937 2,615
CONTOOCOOK RIVER New Hampshire Scour Critical — Countermeasures Installed Fair 1981 2,615
CLIMBERS RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1982 2,614
POWELL CREEK Oregon Scour Critical — Countermeasures Installed Fair 1940 2,612
RIDLEY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1960 2,611
SPRDG TEX LINE JOHNSON B Louisiana Scour Critical — Countermeasures Installed Fair 1979 2,606

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.