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
ELIZABETH CREEK Texas Scour Critical — Countermeasures Installed Fair 2005 3,470
ROBINSON RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1980 3,469
Siletz River Oregon Scour Critical — Countermeasures Installed Fair 1956 3,467
SISTER GROVE CREEK Texas Scour Critical — Countermeasures Installed Good 1975 3,466
PHILLIPS CREEK (ELGIN) Oregon Scour Critical — Countermeasures Installed Fair 1963 3,466
MAHANOY CREEK. Pennsylvania Scour Critical — Countermeasures Installed Fair 1983 3,464
BIG FISHDAM RIVER Michigan Scour Critical — Countermeasures Installed Fair 1936 3,462
PANTHER CREEK Alabama Scour Critical — Countermeasures Installed Fair 1952 3,462
MILL BAYOU Louisiana Scour Critical — Countermeasures Installed Poor 1957 3,462
MILL CREEK Kansas Scour Critical — Countermeasures Installed Fair 1987 3,458
Crabtree Creek Oregon Scour Critical — Countermeasures Installed Fair 1954 3,452
COUNTY ROAD Alabama Scour Critical — Countermeasures Installed Fair 1968 3,450
ALABAMA RIVER REL. Alabama Scour Critical — Countermeasures Installed Fair 1968 3,450
ALABAMA RIVER REL. Alabama Scour Critical — Countermeasures Installed Fair 1968 3,450
ALABAMA RIVER REL. Alabama Scour Critical — Countermeasures Installed Fair 1968 3,450
ALABAMA RIVER REL. Alabama Scour Critical — Countermeasures Installed Fair 1968 3,450
ALABAMA RIVER Alabama Scour Critical — Countermeasures Installed Fair 1969 3,450
Nashville Creek W Branch Illinois Scour Critical — Countermeasures Installed Fair 1921 3,450
NNRR & E. SQUAW CREEK Nevada Scour Critical — Countermeasures Installed Fair 1974 3,450
NNRR & E. SQUAW CREEK Nevada Scour Critical — Countermeasures Installed Fair 1974 3,450
KANE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1959 3,442
MAJADA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1984 3,442
Stamford Mill River New York Scour Critical — Countermeasures Installed Fair 1930 3,441
OVER SUGAR RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 3,441
S FORK SABINE RIVER Texas Scour Critical — Countermeasures Installed Good 2006 3,440
TRIB. HOKENDAUQUA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1932 3,436
LTL INDIAN CR CSX RR Indiana Scour Critical — Countermeasures Installed Fair 1993 3,434
SUMNER BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1935 3,433
PRAIRIE CREEK Washington Scour Critical — Countermeasures Installed Fair 1936 3,433
WABASCON CREEK Michigan Scour Critical — Countermeasures Installed Fair 1929 3,430
MARSHALL BRANCH CREEK Texas Scour Critical — Countermeasures Installed Fair 1994 3,426
MERCED RIVER California Scour Critical — Countermeasures Installed Fair 1928 3,425
KNOB CREEK Kentucky Scour Critical — Countermeasures Installed Fair 1941 3,423
Minto Creek Oregon Scour Critical — Countermeasures Installed Fair 1934 3,423
CATSKILL CREEK New York Scour Critical — Countermeasures Installed Fair 1825 3,422
NEIL CREEK Oregon Scour Critical — Countermeasures Installed Good 1966 3,421
FLATWOODS CREEK Louisiana Scour Critical — Countermeasures Installed Poor 1977 3,420
ST. JOHNS CREEK Louisiana Scour Critical — Countermeasures Installed Poor 1977 3,420
EAGLE DRAW New Mexico Scour Critical — Countermeasures Installed Fair 1969 3,419
MILL CREEK Oregon Scour Critical — Countermeasures Installed Poor 1966 3,417
MONTOUR RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1950 3,416
MERCED RIVER California Scour Critical — Countermeasures Installed Poor 1933 3,416
WINNIPESAUKEE RIVER New Hampshire Scour Critical — Countermeasures Installed Fair 1982 3,412
SALEM CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1919 3,406
LITTLE JUNIATA RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1898 3,406
KAWKAWLIN RIVER Michigan Scour Critical — Countermeasures Installed Fair 1928 3,404
LITTLE WABASH RIVER Indiana Scour Critical — Countermeasures Installed Good 1986 3,404
Creek Florida Scour Critical — Countermeasures Installed Fair 1940 3,400
LYNCHES RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1961 3,400
CRUCES RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1952 3,400

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.