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
SCULLS CREEK Georgia Scour Critical — Countermeasures Installed Fair 2006 2,580
LITTLE TIRED CREEK Georgia Scour Critical — Countermeasures Installed Good 2009 2,580
BOOTS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1976 2,580
CABIN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1931 2,577
ROCK CREEK Kansas Scour Critical — Countermeasures Installed Good 1983 2,575
M FORK WILDCAT CREEK Indiana Scour Critical — Countermeasures Installed Fair 1981 2,574
M FORK WILDCAT CREEK Indiana Scour Critical — Countermeasures Installed Fair 1942 2,573
HATCHEL CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1973 2,571
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1932 2,570
BRESLAU CREEK Nebraska Scour Critical — Countermeasures Installed Poor 1934 2,570
Banana River Florida Scour Critical — Countermeasures Installed Fair 1927 2,569
FAIRFIELD CANAL California Scour Critical — Countermeasures Installed Fair 1950 2,569
WASTEWAY-FAIRFIELD CANAL California Scour Critical — Countermeasures Installed Good 1960 2,569
Crystal River Colorado Scour Critical — Countermeasures Installed Fair 1950 2,569
OVER CUSSEWAGO CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1955 2,568
BAYOU DARBONNE Louisiana Scour Critical — Countermeasures Installed Fair 1978 2,567
NINNESCAH (S F) RIVER Kansas Scour Critical — Countermeasures Installed Good 1988 2,565
SNAKE CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1944 2,561
COHAS BROOK New Hampshire Scour Critical — Countermeasures Installed Good 1900 2,560
SIMMONS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1921 2,556
FROG CREEK Kansas Scour Critical — Countermeasures Installed Fair 1974 2,555
LITTLE SWATARA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1928 2,553
CANASAWACTA CREEK New York Scour Critical — Countermeasures Installed Fair 1937 2,552
OVER CROOKED CREEK TRIB Pennsylvania Scour Critical — Countermeasures Installed Fair 1921 2,552
POWDER RIVER (BRIDGE ST) Oregon Scour Critical — Countermeasures Installed Fair 1933 2,551
MUDDY RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1932 2,551
TRIB OF KICKAPOO CR Illinois Scour Critical — Countermeasures Installed Fair 1928 2,550
MISSISSIPPI RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1971 2,550
SAND CREEK North Dakota Scour Critical — Countermeasures Installed Fair 1960 2,550
COWANSHANNOCK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1962 2,549
THREE MILE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1935 2,548
SADDLE RIVER (E. BRANCH) New Jersey Scour Critical — Countermeasures Installed Fair 1946 2,545
SUGAR RIVER Michigan Scour Critical — Countermeasures Installed Fair 1954 2,536
W BR TITTABAWASSEE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1954 2,536
LITTLE TOBACCO RIVER Michigan Scour Critical — Countermeasures Installed Fair 1958 2,536
TITTABAWASSEE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1928 2,536
SPRING BRANCH Louisiana Scour Critical — Countermeasures Installed Fair 1963 2,534
STONEY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1929 2,533
MAPLE RIVER Michigan Scour Critical — Countermeasures Installed Poor 1929 2,533
ST AUGUSTA CREEK Minnesota Scour Critical — Countermeasures Installed Fair 1935 2,533
COTTONWOOD CREEK Texas Scour Critical — Countermeasures Installed Fair 1946 2,533
RUTHERFORD FK.OBION RIVE Tennessee Scour Critical — Countermeasures Installed Fair 1975 2,532
EIGHT MILE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1939 2,528
ARROYO DEL PUERTO New Mexico Scour Critical — Countermeasures Installed Fair 1957 2,527
MADISON RIVER Wyoming Scour Critical — Countermeasures Installed Poor 1958 2,525
Dodson Wash Arizona Scour Critical — Countermeasures Installed Fair 1964 2,525
Roach Wash Arizona Scour Critical — Countermeasures Installed Fair 1965 2,525
Wash Arizona Scour Critical — Countermeasures Installed Fair 1964 2,525
WILDCAT CREEK Kansas Scour Critical — Countermeasures Installed Good 1967 2,524
JONES CREEK Washington Scour Critical — Countermeasures Installed Good 1931 2,524

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.