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
SPARKILL CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1906 22,073
Intracoastal Waterway Florida Scour Critical — Countermeasures Installed Fair 1979 22,000
W. LITTLE LLAGAS CREEK California Scour Critical — Countermeasures Installed Good 1965 22,000
BOISE RIVER;N. CHANNEL Idaho Scour Critical — Countermeasures Installed Good 1992 22,000
ANCLOTE RIVER Florida Scour Critical — Countermeasures Installed Fair 1972 22,000
FOUNTAIN CREEK Colorado Scour Critical — Countermeasures Installed Poor 1965 22,000
W FRK E BR WHITE CLAY CR Pennsylvania Scour Critical — Countermeasures Installed Fair 1965 21,979
E.FRK BR. WHITE CLAY CR Pennsylvania Scour Critical — Countermeasures Installed Fair 1965 21,979
TURKEY CREEK Texas Scour Critical — Countermeasures Installed Fair 1939 21,969
SWIFTWATER CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1957 21,965
SCOT RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1948 21,965
MCAIN CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1993 21,933
THIRD RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1954 21,931
PASSAIC RIVER New Jersey Scour Critical — Countermeasures Installed Poor 1908 21,920
TRIB TO LITTLE MILL CRK Delaware Scour Critical — Countermeasures Installed Good 1949 21,909
FIVE MILE RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1850 21,900
MARSHALLS CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1930 21,886
WOODBURY CREEK New Jersey Scour Critical — Countermeasures Installed Poor 1892 21,874
SAGINAW RV;MARTIN ST&RR Michigan Scour Critical — Countermeasures Installed Fair 1976 21,832
COWLITZ RIVER Washington Scour Critical — Countermeasures Installed Fair 1953 21,828
COWLITZ RIVER Washington Scour Critical — Countermeasures Installed Poor 1953 21,828
DOAN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1961 21,800
DOAN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1961 21,800
LEHIGH RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1912 21,778
CSX RR & UNNAMED CREEK Michigan Scour Critical — Countermeasures Installed Fair 1949 21,772
CSX RR & UNNAMED CREEK Michigan Scour Critical — Countermeasures Installed Fair 1958 21,772
PRINGLE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1928 21,752
PONCHATOULA CR. Louisiana Scour Critical — Countermeasures Installed Good 1960 21,736
COMB AMTRAK & CONN RIV Massachusetts Scour Critical — Countermeasures Installed Fair 1922 21,706
JESSE LITTLE DITCH Indiana Scour Critical — Countermeasures Installed Fair 1964 21,697
BROWN DITCH Indiana Scour Critical — Countermeasures Installed Fair 1964 21,697
Calapooia Oflow Oregon Scour Critical — Countermeasures Installed Fair 1958 21,606
Sodom Ditch Oflow Oregon Scour Critical — Countermeasures Installed Fair 1959 21,606
Courtney Creek Oregon Scour Critical — Countermeasures Installed Fair 1959 21,606
Sodom Ditch Oflow Oregon Scour Critical — Countermeasures Installed Fair 1959 21,606
Courtney Creek Oregon Scour Critical — Countermeasures Installed Fair 1959 21,606
Calapooia Oflow Oregon Scour Critical — Countermeasures Installed Fair 1958 21,606
Sodom Ditch Oflow Oregon Scour Critical — Countermeasures Installed Fair 1958 21,606
Courtney Creek Oflow Oregon Scour Critical — Countermeasures Installed Fair 1959 21,606
Sodom Ditch Oflow Oregon Scour Critical — Countermeasures Installed Fair 1958 21,606
Calapooia Oflow Oregon Scour Critical — Countermeasures Installed Fair 1958 21,606
Courtney Creek Oflow Oregon Scour Critical — Countermeasures Installed Fair 1959 21,606
Calapooia Oflow Oregon Scour Critical — Countermeasures Installed Good 1958 21,606
MILL BRANCH Texas Scour Critical — Countermeasures Installed Fair 1986 21,577
BUFFALO CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 21,561
CURLEW CREEK Florida Scour Critical — Countermeasures Installed Good 1986 21,500
Intracoastal Waterway Florida Scour Critical — Countermeasures Installed Fair 1956 21,500
WATER CHARLES RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1967 21,500
CEDAR CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1923 21,480
WYNOOCHEE RIVER Washington Scour Critical — Countermeasures Installed Poor 1935 21,466

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.