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
BR PINE R Michigan Scour Critical — Countermeasures Installed Fair 1947 3,850
PINE RIVER Michigan Scour Critical — Countermeasures Installed Poor 1957 3,850
GOFFLE BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1958 3,850
APPLE CREEK North Dakota Scour Critical — Countermeasures Installed Fair 1965 3,850
HOUGHS CREEK / 3038-J5 Pennsylvania Scour Critical — Countermeasures Installed Poor 1910 3,839
DELAWARE CANAL/3151-F2 Pennsylvania Scour Critical — Countermeasures Installed Fair 1932 3,837
MILLER CREEK California Scour Critical — Countermeasures Installed Good 1970 3,830
RAYSTOWN BR.JUNIATA RIV. Pennsylvania Scour Critical — Countermeasures Installed Fair 1934 3,829
STONY BROOK Connecticut Scour Critical — Countermeasures Installed Poor 1935 3,820
SECOND COW CREEK Kansas Scour Critical — Countermeasures Installed Good 1980 3,817
BLACK CR OVERFLOW New York Scour Critical — Countermeasures Installed Poor 1927 3,816
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Good 1924 3,815
E FK WHITE RIVER OVFL Indiana Scour Critical — Countermeasures Installed Fair 1981 3,814
MILLECOQUIN RIVER Michigan Scour Critical — Countermeasures Installed Fair 1940 3,813
SANBORN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1934 3,813
BALDWIN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1931 3,813
BLACKSTONE RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1885 3,811
MILL CREEK Texas Scour Critical — Countermeasures Installed Good 1951 3,810
MILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1905 3,809
EAST BR BRANDYWINE CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1950 3,807
KASKASKIA ST MISSISSI Missouri Scour Critical — Countermeasures Installed Poor 1942 3,806
HORSE ISLAND CHUTE Missouri Scour Critical — Countermeasures Installed Poor 1942 3,806
LIMESTONE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1936 3,806
LAKE CREEK Washington Scour Critical — Countermeasures Installed Fair 1946 3,805
GRANDE RONDE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1965 3,803
MOLE CREEK Wisconsin Scour Critical — Countermeasures Installed Good 2015 3,800
GUAMANI RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1925 3,800
GUAYANES RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1969 3,800
FRENCH RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1935 3,800
MARYS RIVER Oregon Scour Critical — Countermeasures Installed Fair 1953 3,800
PUGET SOUND @ SEATTLE Washington Scour Critical — Countermeasures Installed Fair 1971 3,800
BURCH CREEK California Scour Critical — Countermeasures Installed Fair 1914 3,800
BIG SANDY CREEK Colorado Scour Critical — Countermeasures Installed Fair 1971 3,800
MUD CREEK Indiana Scour Critical — Countermeasures Installed Fair 1947 3,800
PORTER SLOUGH California Scour Critical — Countermeasures Installed Fair 1930 3,800
ISNER CREEK West Virginia Scour Critical — Countermeasures Installed Poor 1939 3,800
BLACK CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1930 3,799
RATTLESNAKE CREEK Washington Scour Critical — Countermeasures Installed Good 1947 3,793
OVER FRENCH CREEK E BR Pennsylvania Scour Critical — Countermeasures Installed Poor 1925 3,791
NORWALK RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1928 3,790
BIG BLUE RIVER Indiana Scour Critical — Countermeasures Installed Fair 1926 3,784
BUTLER CREEK Indiana Scour Critical — Countermeasures Installed Fair 1992 3,783
FALL CREEK Indiana Scour Critical — Countermeasures Installed Fair 1998 3,783
ROGUE RIVER - DODGE BR Oregon Scour Critical — Countermeasures Installed Fair 1953 3,782
PICOU BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1955 3,782
BAYOU BARBARY Louisiana Scour Critical — Countermeasures Installed Fair 1955 3,782
TRIB TO CONEMAUGH RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1942 3,779
FRENCH DITCH Indiana Scour Critical — Countermeasures Installed Fair 1934 3,777
SWAN CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1916 3,776
W BR BRANDYWINE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1923 3,775

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.