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
SHEEP HAMMOCK CREEK Florida Scour Critical — Countermeasures Installed Fair 1927 10,600
BUTTERMILK SLOUGH N FORK Florida Scour Critical — Countermeasures Installed Fair 1927 10,600
GRANDE DE MANATI RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1968 10,600
GRANDE DE MANATI RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1968 10,600
JANER CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1924 10,600
WATER ABERJONA RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1890 10,600
PASSAIC RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1898 10,590
MUCKLEROY CREEK Alabama Scour Critical — Countermeasures Installed Fair 1961 10,585
MUCKLEROY CREEK Alabama Scour Critical — Countermeasures Installed Fair 1961 10,585
COMB ST112 & DEERFLD R Massachusetts Scour Critical — Countermeasures Installed Fair 1954 10,562
ALABAMA RIVER Alabama Scour Critical — Countermeasures Installed Fair 1970 10,540
ALA. RIVER RELIEF #3 Alabama Scour Critical — Countermeasures Installed Fair 1970 10,540
DARDENNE CR Missouri Scour Critical — Countermeasures Installed Fair 1974 10,518
McClellan Wash Arizona Scour Critical — Countermeasures Installed Fair 1960 10,511
Santa Cruz Wash Arizona Scour Critical — Countermeasures Installed Fair 1960 10,511
MAR DES CYG RIV PD PASS Kansas Scour Critical — Countermeasures Installed Fair 1958 10,506
MAR DES CYG RIV PD PASS Kansas Scour Critical — Countermeasures Installed Fair 1958 10,506
INTRACOASTAL WATERWAY Florida Scour Critical — Countermeasures Installed Fair 1985 10,502
SILVERSMITH CREEK Florida Scour Critical — Countermeasures Installed Good 1980 10,501
HEMBREE CREEK South Carolina Scour Critical — Countermeasures Installed Good 1988 10,500
WATER COYS BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1901 10,500
WILLS BRANCH Florida Scour Critical — Countermeasures Installed Good 1969 10,500
PETTAQUAMSCUTT RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1934 10,491
ALBERTSONS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1930 10,490
GREAT SWAMP BRANCH New Jersey Scour Critical — Countermeasures Installed Fair 1930 10,475
WOLF RIVER Tennessee Scour Critical — Countermeasures Installed Poor 1980 10,454
ALABAMA RIVER Alabama Scour Critical — Countermeasures Installed Fair 1955 10,450
Santa Cruz River Arizona Scour Critical — Countermeasures Installed Fair 1960 10,449
CAYUGA CREEK New York Scour Critical — Countermeasures Installed Fair 1931 10,449
ST JOHNS DTCH Missouri Scour Critical — Countermeasures Installed Fair 1964 10,439
LAMINGTON RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1988 10,424
NIX CREEK Arkansas Scour Critical — Countermeasures Installed Fair 1950 10,414
DOS BOCAS CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1980 10,400
HARDY MILL CREEK Georgia Scour Critical — Countermeasures Installed Good 1988 10,400
MAD RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1935 10,400
KAIEIE STRM Hawaii Scour Critical — Countermeasures Installed Fair 1967 10,400
CROOKED OAK CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1942 10,400
Willamette River Oregon Scour Critical — Countermeasures Installed Fair 1925 10,393
WAIBLE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1972 10,382
NASH CREEK Michigan Scour Critical — Countermeasures Installed Fair 1962 10,377
N. FK. FORKED DEER RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1959 10,376
N. FK. FORKED DEER RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1959 10,376
JAMES RIVER North Dakota Scour Critical — Countermeasures Installed Fair 1960 10,370
S BR SHIAWASSEE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1918 10,370
WOODY BRANCH Texas Scour Critical — Countermeasures Installed Good 1985 10,361
FIVE MILE CREEK Texas Scour Critical — Countermeasures Installed Fair 1970 10,356
WHITE OAK CREEK Texas Scour Critical — Countermeasures Installed Fair 1947 10,351
North Yamhill River Oregon Scour Critical — Countermeasures Installed Fair 1921 10,350
CLIFTY CREEK Indiana Scour Critical — Countermeasures Installed Good 1962 10,341
PADANARAM BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1899 10,334

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.