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
RED BRANCH Louisiana Scour Critical — Countermeasures Installed Fair 1979 3,124
LICKING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1935 3,124
MAMARONECK RIVER New York Scour Critical — Countermeasures Installed Poor 1900 3,122
FLATROCK RIVER Indiana Scour Critical — Countermeasures Installed Fair 1992 3,120
SLOUGH Louisiana Scour Critical — Countermeasures Installed Good 1974 3,120
TERRYS CREEK Louisiana Scour Critical — Countermeasures Installed Good 1974 3,120
TANG. R. W.RELIEF Louisiana Scour Critical — Countermeasures Installed Good 1975 3,120
TANGIPAHOA RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1974 3,120
TANGIPAHOA RIVER E RELIE Louisiana Scour Critical — Countermeasures Installed Good 1975 3,120
Chehulpum Creek Oregon Scour Critical — Countermeasures Installed Fair 1919 3,115
BUTTERNUT CREEK Michigan Scour Critical — Countermeasures Installed Fair 1927 3,115
LITTLE WHITE OAK BAYOU Texas Scour Critical — Countermeasures Installed Fair 1955 3,115
HUNLOCK CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1925 3,114
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1968 3,114
OBION RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1968 3,114
LTI CREEK Louisiana Scour Critical — Countermeasures Installed Fair 2015 3,111
NORTH SUGAR CREEK Kansas Scour Critical — Countermeasures Installed Good 1982 3,109
WEST BR.CHESTER CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1973 3,108
E BR PEMIGEWASSET RIVER New Hampshire Scour Critical — Countermeasures Installed Fair 1938 3,107
SHOTGUN CREEK Oregon Scour Critical — Countermeasures Installed Fair 1964 3,106
EAST BR PEQUEST RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1939 3,105
PAWCATUCK RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1926 3,102
DEER CREEK Michigan Scour Critical — Countermeasures Installed Fair 1933 3,101
DRY CREEK CANAL California Scour Critical — Countermeasures Installed Fair 1935 3,101
ST CATHERINE CREEK Mississippi Scour Critical — Countermeasures Installed Good 1998 3,100
GROVE CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1971 3,100
TRIB CARPENTER CK (1) South Carolina Scour Critical — Countermeasures Installed Poor 1959 3,100
TRIB CARPENTER CK (2) South Carolina Scour Critical — Countermeasures Installed Fair 1959 3,100
REEDY RIVER South Carolina Scour Critical — Countermeasures Installed Good 1988 3,100
COOSAWHATCHIE RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1996 3,100
LYMAN BROOK Vermont Scour Critical — Countermeasures Installed Fair 1929 3,100
PRIEST RIVER Idaho Scour Critical — Countermeasures Installed Poor 1962 3,100
BR CEDAR CREEK Wisconsin Scour Critical — Countermeasures Installed Fair 1940 3,100
STURGEON CREEK Michigan Scour Critical — Countermeasures Installed Fair 1981 3,100
SLEEPY CREEK West Virginia Scour Critical — Countermeasures Installed Poor 1900 3,100
LA MINA CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1961 3,100
MINETTA BRANCH Florida Scour Critical — Countermeasures Installed Poor 1924 3,100
LA MANUELA CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1955 3,100
SANTIAGO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1955 3,100
ONION RIVER Wisconsin Scour Critical — Countermeasures Installed Fair 1936 3,100
DE NEVEU CREEK Wisconsin Scour Critical — Countermeasures Installed Poor 1965 3,100
ST LUCIE CANAL Florida Scour Critical — Countermeasures Installed Good 1980 3,100
GUAYNABO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1985 3,100
MUSKEGO CANAL Wisconsin Scour Critical — Countermeasures Installed Fair 1925 3,100
PATILLAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1956 3,100
ALAMO ALTO DRAIN Texas Scour Critical — Countermeasures Installed Good 2011 3,095
DRAINAGE CANAL Louisiana Scour Critical — Countermeasures Installed Good 2007 3,094
MUD CREEK Indiana Scour Critical — Countermeasures Installed Fair 1976 3,093
MUD CREEK Indiana Scour Critical — Countermeasures Installed Good 1971 3,093
SANDY CREEK Louisiana Scour Critical — Countermeasures Installed Poor 1979 3,092

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.