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
JUAN MARTIN RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1916 4,000
SAWMILL RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1928 4,000
PACK RIVER Idaho Scour Critical — Countermeasures Installed Fair 1978 4,000
BLUE RIBBON ARROYO Colorado Scour Critical — Countermeasures Installed Fair 1950 4,000
W BRANCH SAUGATUCK RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1957 4,000
IRENE CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1954 4,000
ANDOVER BRANCH Vermont Scour Critical — Countermeasures Installed Fair 1933 4,000
SPRING CREEK Texas Scour Critical — Countermeasures Installed Good 1989 4,000
Hogskin Lake Creek Louisiana Scour Critical — Countermeasures Installed Fair 1989 4,000
MANCOS RIVER Colorado Scour Critical — Countermeasures Installed Fair 1959 4,000
INDIAN CREEK Colorado Scour Critical — Countermeasures Installed Fair 1959 4,000
Partin Canal Florida Scour Critical — Countermeasures Installed Fair 1973 4,000
WARRIOR RIVER RELIEF Alabama Scour Critical — Countermeasures Installed Fair 1927 3,997
WARRIOR RIVER RELIEF Alabama Scour Critical — Countermeasures Installed Fair 1927 3,997
WARRIOR RIVER RELIEF Alabama Scour Critical — Countermeasures Installed Fair 1941 3,997
PASCACK BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1981 3,997
SUGAR CREEK Pennsylvania Scour Critical — Countermeasures Installed Good 1957 3,993
BRANCH OF POMPESTON CK New Jersey Scour Critical — Countermeasures Installed Fair 1961 3,992
ANDERSON ARROYO Colorado Scour Critical — Countermeasures Installed Poor 1931 3,981
HAIRS CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1960 3,980
NAVASOTA RIVER E RELIEF Texas Scour Critical — Countermeasures Installed Fair 1940 3,978
SULLIVAN DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1987 3,977
SYCAMORE RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1950 3,974
ELDER RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1951 3,972
CANOVANAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1947 3,972
PRAIRIE CREEK Oregon Scour Critical — Countermeasures Installed Good 1985 3,969
QUITTAPAHILLA CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1967 3,968
CLEAR BROOK Delaware Scour Critical — Countermeasures Installed Fair 1919 3,966
N CHUCTANUNDA CK New York Scour Critical — Countermeasures Installed Poor 1912 3,960
BUCK CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1932 3,958
TRIB DELAWARE RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1928 3,958
DYERS CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 3,958
HOUGHS CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1933 3,958
SANDY HOOK DITCH Indiana Scour Critical — Countermeasures Installed Fair 1952 3,957
DELAWARE CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1952 3,956
DELAWARE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1952 3,956
DEER CREEK Indiana Scour Critical — Countermeasures Installed Good 1987 3,955
CREEK Louisiana Scour Critical — Countermeasures Installed Poor 1954 3,955
CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1960 3,954
EAST BR BRANDYWINE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1941 3,954
RED GULLY Texas Scour Critical — Countermeasures Installed Fair 1977 3,953
ST JOSEPH RIVER Michigan Scour Critical — Countermeasures Installed Good 1947 3,950
DRAW Texas Scour Critical — Countermeasures Installed Fair 1960 3,949
Wash Arizona Scour Critical — Countermeasures Installed Good 1951 3,947
N TUPAWEK BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1978 3,947
COUNTY DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1939 3,942
ROSILLO CREEK Texas Scour Critical — Countermeasures Installed Fair 2005 3,942
PAWNEE CREEK Nebraska Scour Critical — Countermeasures Installed Fair 1935 3,940
TEETER CREEK Oregon Scour Critical — Countermeasures Installed Fair 1974 3,939
ECHO CREEK Utah Scour Critical — Countermeasures Installed Fair 1924 3,938

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.