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
PAWCATUCK RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1930 6,243
W FORK GOOSE CRK Texas Scour Critical — Countermeasures Installed Fair 1991 6,242
MILL BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1970 6,236
HILLS BRANCH Indiana Scour Critical — Countermeasures Installed Fair 1990 6,236
FERGUSON CREEK FERGUSON New York Scour Critical — Countermeasures Installed Poor 1965 6,235
USRS CANAL Oregon Scour Critical — Countermeasures Installed Fair 1949 6,228
WANITY SLOUGH Washington Scour Critical — Countermeasures Installed Poor 1964 6,219
WANITY SLOUGH Washington Scour Critical — Countermeasures Installed Good 1948 6,219
SPRING GARDEN BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1928 6,219
EAST FORK HONEY CREEK Indiana Scour Critical — Countermeasures Installed Fair 1994 6,216
FISHING RVR Missouri Scour Critical — Countermeasures Installed Good 1980 6,212
COLUMBIA RIVER Washington Scour Critical — Countermeasures Installed Fair 1962 6,212
BENTLE BRANCH Texas Scour Critical — Countermeasures Installed Fair 1950 6,208
102 RVR Missouri Scour Critical — Countermeasures Installed Fair 1985 6,207
WATER VINE BROOK Massachusetts Scour Critical — Countermeasures Installed Good 1998 6,207
FRANK & POET DRAIN Michigan Scour Critical — Countermeasures Installed Poor 1932 6,206
POWDER RIVER Oregon Scour Critical — Countermeasures Installed Fair 1972 6,205
POWDER RIVER Oregon Scour Critical — Countermeasures Installed Fair 1972 6,205
Hurricane Creek Relief Arkansas Scour Critical — Countermeasures Installed Fair 1948 6,200
CACHE CREEK California Scour Critical — Countermeasures Installed Fair 1955 6,200
COLONELS FORK CREEK South Carolina Scour Critical — Countermeasures Installed Good 1974 6,200
GUNNISON RIVER Colorado Scour Critical — Countermeasures Installed Fair 1957 6,200
CANEY BRANCH Florida Scour Critical — Countermeasures Installed Fair 1966 6,200
CANCEL CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1920 6,200
TRIB.SWATARA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1928 6,200
Hubbard Creek Arkansas Scour Critical — Countermeasures Installed Poor 1948 6,200
COTTONWOOD RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1983 6,200
LITTLE KANAWHA RIVER West Virginia Scour Critical — Countermeasures Installed Poor 1929 6,200
INDIAN MEADOW BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1940 6,200
MOSHASSUCK RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1887 6,200
Chatlin Lake Canal Louisiana Scour Critical — Countermeasures Installed Good 2006 6,200
DENISON BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1934 6,200
OLALLA CREEK Oregon Scour Critical — Countermeasures Installed Fair 1949 6,199
MUSSER RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1935 6,199
LOPATCONG CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1928 6,194
CLATSKANIE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1934 6,189
FLOODWAY DITCH Oregon Scour Critical — Countermeasures Installed Fair 1964 6,188
FLOODWAY DITCH Oregon Scour Critical — Countermeasures Installed Fair 1964 6,188
HARBOR BROOK Connecticut Scour Critical — Countermeasures Installed Poor 1871 6,186
BIG DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1958 6,182
MORRIS & CUMMINGS CUT Texas Scour Critical — Countermeasures Installed Fair 1994 6,181
HONEY CR Missouri Scour Critical — Countermeasures Installed Fair 1972 6,177
ROUGE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1952 6,175
PRICKLY PEAR CREEK Montana Scour Critical — Countermeasures Installed Fair 1941 6,170
WEST BR. RED CLAY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1940 6,163
TR.EVITTS CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1964 6,158
San Pedro River Arizona Scour Critical — Countermeasures Installed Poor 1960 6,156
MORRIS MILL POND Delaware Scour Critical — Countermeasures Installed Fair 1932 6,149
DOWAGIAC RIVER Michigan Scour Critical — Countermeasures Installed Fair 1952 6,146
PEQUEST RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1922 6,145

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.