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
Dania Cut-Off Canal Florida Scour Critical — Countermeasures Installed Fair 1931 53,000
Drainage Ditch Texas Scour Critical — Countermeasures Installed Fair 1961 52,733
CR 632 & MUSCONET RIV New Jersey Scour Critical — Countermeasures Installed Fair 1959 52,610
TURKEY CR MILL STREET Kansas Scour Critical — Countermeasures Installed Good 1961 52,500
TURKEY CR MILL STREET Kansas Scour Critical — Countermeasures Installed Good 1961 52,500
LA PLATA RIVER & PR Puerto Rico Scour Critical — Countermeasures Installed Fair 1985 52,500
OLD WM PENN HWY LEAK RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1962 52,457
Grand Canal Arizona Scour Critical — Countermeasures Installed Fair 1979 52,404
PENNYPACK CRK;PATHS Pennsylvania Scour Critical — Countermeasures Installed Fair 1920 52,330
HARRIS CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1965 52,149
SEQUATCHIE RIVER Tennessee Scour Critical — Countermeasures Installed Poor 1965 52,102
SEQUATCHIE RIVER Tennessee Scour Critical — Countermeasures Installed Poor 1965 52,102
ELM CREEK Texas Scour Critical — Countermeasures Installed Good 1934 52,065
CLEAR CREEK Oregon Scour Critical — Countermeasures Installed Fair 1930 51,600
BRANCH MCCRACKEN CREEK Indiana Scour Critical — Countermeasures Installed Fair 1966 51,175
BRANCH MCCRACKEN CREEK Indiana Scour Critical — Countermeasures Installed Fair 1966 51,175
N BRANCH MCCRACKEN CREEK Indiana Scour Critical — Countermeasures Installed Good 1966 51,175
CLARKS CREEK Indiana Scour Critical — Countermeasures Installed Good 1966 51,175
STONY BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1929 50,500
ROARING BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1955 50,400
S. BR. RARITAN RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1958 49,741
SOUTH BR. RARITAN RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1957 49,741
CLINTON RIVER N&S RDS Michigan Scour Critical — Countermeasures Installed Fair 1947 49,601
CLINTON RIVER N&S RDS Michigan Scour Critical — Countermeasures Installed Fair 1963 49,601
BRADEN RIVER EAST BRANCH Florida Scour Critical — Countermeasures Installed Good 1988 49,500
CROSS BAYOU Florida Scour Critical — Countermeasures Installed Fair 1976 49,500
MATTABESSET RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1965 49,200
MILL BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1932 48,987
IRRIGATION CHANNEL Puerto Rico Scour Critical — Countermeasures Installed Fair 1986 48,600
HIWASSEE RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1968 48,545
HIWASSEE RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1968 48,545
SOUTH PLATTE RIVER Colorado Scour Critical — Countermeasures Installed Poor 1969 48,500
HAT CREEK Georgia Scour Critical — Countermeasures Installed Good 1958 48,500
JUAN GONZALEZ CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1976 48,100
FEATHER RIVER K ST UP RR California Scour Critical — Countermeasures Installed Fair 1947 48,000
NVRR NAPA RIVER STANLY California Scour Critical — Countermeasures Installed Poor 1977 48,000
ASHLEY RIVER South Carolina Scour Critical — Countermeasures Installed Poor 1953 47,800
MOUSE CREEK Tennessee Scour Critical — Countermeasures Installed Good 1971 47,306
MOUSE CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1971 47,306
PASSAIC RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1940 47,094
I 25 ML FOUNTAIN CRK Colorado Scour Critical — Countermeasures Installed Fair 1990 47,000
NESHAMINY CR & SR 2027 Pennsylvania Scour Critical — Countermeasures Installed Fair 1964 46,995
LICK CREEK Indiana Scour Critical — Countermeasures Installed Good 1963 46,611
CA¥AS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1953 46,400
CLEAR CREEK BP R Colorado Scour Critical — Countermeasures Installed Fair 1981 46,000
STILLAGUAMISH RIVER Washington Scour Critical — Countermeasures Installed Fair 1933 45,626
STILLAGUAMISH R Washington Scour Critical — Countermeasures Installed Fair 1971 45,626
ABITA RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1975 45,574
CANOVANAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1956 45,200
Willamette River Oregon Scour Critical — Countermeasures Installed Fair 1953 45,083

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.