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
HURON RIVER Michigan Scour Critical — Countermeasures Installed Fair 1971 102,776
FALL CREEK & TRAIL Indiana Scour Critical — Countermeasures Installed Fair 1966 101,476
MATTABESSET RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1965 99,500
Mason Creek Texas Scour Critical — Countermeasures Installed Good 2005 99,354
FALL CREEK & TRAIL Indiana Scour Critical — Countermeasures Installed Fair 1966 97,835
Willamette River Oregon Scour Critical — Countermeasures Installed Fair 1970 97,105
PIPE MAKERS CANAL Georgia Scour Critical — Countermeasures Installed Good 1976 96,600
JONES FALLS & UNION AVE Maryland Scour Critical — Countermeasures Installed Fair 1959 95,051
CAGUITAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1964 93,200
CARMEL CREEK Indiana Scour Critical — Countermeasures Installed Fair 1967 92,625
CARMEL CREEK Indiana Scour Critical — Countermeasures Installed Fair 1967 92,625
ECHECONNEE CREEK Georgia Scour Critical — Countermeasures Installed Good 1963 92,100
HACKENSACK RIVR & ROAD New Jersey Scour Critical — Countermeasures Installed Poor 1931 92,076
CLEAR CREEK R Colorado Scour Critical — Countermeasures Installed Good 1980 92,000
KEEGANS BAYOU Texas Scour Critical — Countermeasures Installed Fair 1969 89,868
RED RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1972 88,998
FERDUN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1957 88,500
SALT CR Illinois Scour Critical — Countermeasures Installed Fair 1958 87,550
SALT CR Illinois Scour Critical — Countermeasures Installed Fair 1958 87,550
DEEP RUN BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1940 86,421
ST.JOHNS RIV.& MILL COVE Florida Scour Critical — Countermeasures Installed Fair 1989 84,321
HARLEM RVR SHORE New York Scour Critical — Countermeasures Installed Fair 1966 82,471
CST N LEVEE RD MISSOU Missouri Scour Critical — Countermeasures Installed Fair 1972 81,653
Mississippi River Minnesota Scour Critical — Countermeasures Installed Fair 1963 81,500
WATER MERRIMACK RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1962 79,000
SAN JACINTO RIVER Texas Scour Critical — Countermeasures Installed Fair 1974 78,458
AMERICAN RIVER California Scour Critical — Countermeasures Installed Fair 1955 78,370
GRANDE DE LOIZA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 2000 78,200
WEST COLYELL CR Louisiana Scour Critical — Countermeasures Installed Fair 1970 77,469
HWY 1 Oregon Scour Critical — Countermeasures Installed Fair 1963 76,816
BIG BRANCH Louisiana Scour Critical — Countermeasures Installed Fair 1969 75,867
SANDY RUN Pennsylvania Scour Critical — Countermeasures Installed Good 1954 74,921
MERAMEC RVR BACKWOOD DR Missouri Scour Critical — Countermeasures Installed Fair 1954 74,368
BLOOD RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1968 74,180
ECHO LAKE New Jersey Scour Critical — Countermeasures Installed Poor 1929 73,690
ELIZABETH RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1928 73,243
RIPPOWAM RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1936 73,120
POMPESTON CREEK New Jersey Scour Critical — Countermeasures Installed Poor 1925 72,151
HWY 1 I-5 Oregon Scour Critical — Countermeasures Installed Fair 1963 71,767
SAVANNAH RIVER Georgia Scour Critical — Countermeasures Installed Fair 1976 70,500
EIGHTMILE CREEK Alabama Scour Critical — Countermeasures Installed Fair 1965 69,472
CHICKASAW CREEK Alabama Scour Critical — Countermeasures Installed Fair 2003 69,472
WEPAWAUG RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1949 68,300
BIG INDIAN CREEK Georgia Scour Critical — Countermeasures Installed Good 1963 67,800
CONRAIL RAISIN R FRONT Michigan Scour Critical — Countermeasures Installed Poor 1955 67,800
CLOVER CREEK Washington Scour Critical — Countermeasures Installed Fair 1957 67,232
SWARTZ CREEK Michigan Scour Critical — Countermeasures Installed Fair 1954 66,912
LAUREL RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1963 66,529
CLARKS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1966 65,674
WEST FK WHITE LICK CREEK Indiana Scour Critical — Countermeasures Installed Good 1966 65,674

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.