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
LONG BRANCH BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1954 4,612
LONG BRANCH BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1954 4,612
LITTLE INDIAN CREEK Indiana Scour Critical — Countermeasures Installed Fair 1990 4,610
Laprele Creek Wyoming Scour Critical — Countermeasures Installed Fair 1958 4,607
ARKANSAS RIVER DRAINAGE Kansas Scour Critical — Countermeasures Installed Good 1909 4,605
BECKETS RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1915 4,603
SILVER CREEK Maryland Scour Critical — Countermeasures Installed Fair 1940 4,601
ST. MARYS RIVER Georgia Scour Critical — Countermeasures Installed Fair 1927 4,600
BARK RIVER Wisconsin Scour Critical — Countermeasures Installed Fair 1964 4,600
EAST FORK WHITE RIVER Indiana Scour Critical — Countermeasures Installed Fair 1994 4,600
YAMPA RIVER Colorado Scour Critical — Countermeasures Installed Good 1976 4,600
DELAWARE River New Jersey Scour Critical — Countermeasures Installed Fair 1926 4,600
GRANDE DE JAYUYA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1972 4,600
LUCY POINT CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1965 4,600
WALLOOMSAC RIVER Vermont Scour Critical — Countermeasures Installed Fair 1926 4,600
ST. MARYS RIVER Florida Scour Critical — Countermeasures Installed Fair 1927 4,600
JEFFERSON DITCH Wisconsin Scour Critical — Countermeasures Installed Fair 1998 4,600
CENTRAL CREEK Indiana Scour Critical — Countermeasures Installed Fair 1941 4,598
BLACK BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1967 4,595
Willamette River Oregon Scour Critical — Countermeasures Installed Fair 1958 4,595
LITTLE CANEY BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1978 4,595
WARRIOR RIVER RELIEF Alabama Scour Critical — Countermeasures Installed Fair 1927 4,587
IRON ORE CREEK Texas Scour Critical — Countermeasures Installed Fair 1999 4,585
MUD CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1925 4,572
THUNDER BAY RIVER Michigan Scour Critical — Countermeasures Installed Fair 1927 4,572
WATER TEN MILE RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1905 4,571
E. FORK BEAVER CK CANAL Tennessee Scour Critical — Countermeasures Installed Fair 1923 4,571
DEUEL HOLLOW BRK New York Scour Critical — Countermeasures Installed Fair 1932 4,566
CARPENTER CREEK Indiana Scour Critical — Countermeasures Installed Fair 1929 4,557
TOUCHET RIVER Washington Scour Critical — Countermeasures Installed Good 1966 4,556
BIG COVE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 4,554
TITTABAWASSEE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1900 4,550
BOGGS RUN Pennsylvania Scour Critical — Countermeasures Installed Good 1920 4,550
RYAN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1968 4,542
SOUTH UMPQUA RIVER Oregon Scour Critical — Countermeasures Installed Poor 1946 4,541
A-2 CHANNEL Oregon Scour Critical — Countermeasures Installed Fair 1981 4,539
LITTLE RIVER RELIEF Louisiana Scour Critical — Countermeasures Installed Fair 2008 4,538
LITTLE RIVER Louisiana Scour Critical — Countermeasures Installed Good 2008 4,538
COCKERHAM CREEK Louisiana Scour Critical — Countermeasures Installed Good 2008 4,538
DYAS CREEK Alabama Scour Critical — Countermeasures Installed Fair 1951 4,535
AMAZON CANAL Oregon Scour Critical — Countermeasures Installed Fair 1973 4,535
CANAL Louisiana Scour Critical — Countermeasures Installed Fair 1973 4,534
Church Rock Wash Arizona Scour Critical — Countermeasures Installed Fair 1961 4,533
North Santiam River Oregon Scour Critical — Countermeasures Installed Fair 1973 4,530
BLACKWELL CR Missouri Scour Critical — Countermeasures Installed Fair 1964 4,527
NINE MILE CREEK New York Scour Critical — Countermeasures Installed Fair 1921 4,527
PAWLOWSKI CREEK DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1978 4,525
N. FORK HUMBOLDT RIVER Nevada Scour Critical — Countermeasures Installed Good 1962 4,525
N. FORK HUMBOLDT RIVER Nevada Scour Critical — Countermeasures Installed Good 1962 4,525
MUDDY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1950 4,523

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.