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
CRANE CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1922 10,100
ST MARYS RIVER Indiana Scour Critical — Countermeasures Installed Fair 1981 10,100
ST MARYS RIVER Indiana Scour Critical — Countermeasures Installed Poor 1981 10,100
WATER CHARLES RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1922 10,100
South Yamhill River Oregon Scour Critical — Countermeasures Installed Fair 1956 10,099
N. FK. FORKED DEER RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1963 10,097
BABCOCK CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1941 10,090
CABIN RUN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1950 10,089
GINHOUSE CREEK Florida Scour Critical — Countermeasures Installed Poor 1965 10,081
RED CLAY CREEK Delaware Scour Critical — Countermeasures Installed Fair 1931 10,072
WILLIS BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1982 10,070
PARKERS CREEK New Jersey Scour Critical — Countermeasures Installed Poor 1906 10,066
HOUK DITCH Indiana Scour Critical — Countermeasures Installed Fair 1988 10,057
WEST FORK BIG WALNUT CR Indiana Scour Critical — Countermeasures Installed Fair 1963 10,041
WEST FORK BIG WALNUT CR Indiana Scour Critical — Countermeasures Installed Fair 1963 10,041
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1959 10,030
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1959 10,030
OVER MAHONING CR. Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 10,026
SLOAT BROOK Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 10,020
APPLE TREE COVE Washington Scour Critical — Countermeasures Installed Fair 1986 10,000
Ten Mile Creek Texas Scour Critical — Countermeasures Installed Fair 1988 10,000
MISSISSINEWA RIVER Indiana Scour Critical — Countermeasures Installed Fair 1950 10,000
GUAYNABO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1954 10,000
PAHEEHEE STRM Hawaii Scour Critical — Countermeasures Installed Fair 1950 10,000
HANAWI STRM Hawaii Scour Critical — Countermeasures Installed Good 1968 10,000
LOVILLS CREEK North Carolina Scour Critical — Countermeasures Installed Fair 1977 10,000
KALAOA STRM Hawaii Scour Critical — Countermeasures Installed Good 1967 10,000
S.FK.TETON RIVER Idaho Scour Critical — Countermeasures Installed Fair 1980 10,000
S.FK.TETON RIVER Idaho Scour Critical — Countermeasures Installed Fair 1980 10,000
Pennypack Creek Pennsylvania Scour Critical — Countermeasures Installed Poor 1907 10,000
BLACKSTONE RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1910 9,999
BRADFIELD CREEK Texas Scour Critical — Countermeasures Installed Good 1973 9,995
LODAL CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1947 9,993
SADDLE RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1902 9,984
ASHLAND CREEK Oregon Scour Critical — Countermeasures Installed Fair 1911 9,979
FARMERS HIGHLINE CANAL Colorado Scour Critical — Countermeasures Installed Fair 1971 9,958
WATER PASKAMANSETT RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1826 9,957
LITTLE PEE DEE SWP-1 South Carolina Scour Critical — Countermeasures Installed Good 1974 9,950
LITTLE PEE DEE SWP-5 South Carolina Scour Critical — Countermeasures Installed Fair 1974 9,950
LITTLE PEE DEE SWP-5 South Carolina Scour Critical — Countermeasures Installed Fair 1931 9,950
LITTLE PEE DEE SWP-4 South Carolina Scour Critical — Countermeasures Installed Fair 1931 9,950
SOUTH BRUNSWICK RIVER Georgia Scour Critical — Countermeasures Installed Fair 1965 9,950
LITTLE PEE DEE SWP-4 South Carolina Scour Critical — Countermeasures Installed Poor 1974 9,950
LITTLE PEE DEE SWP-2 South Carolina Scour Critical — Countermeasures Installed Fair 1931 9,950
LITTLE PEE DEE SWP-1 South Carolina Scour Critical — Countermeasures Installed Fair 1931 9,950
LITTLE PEE DEE SWP-2 South Carolina Scour Critical — Countermeasures Installed Fair 1974 9,950
CROWS CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1979 9,942
NFK DBL MTN FK BRAZOS RI Texas Scour Critical — Countermeasures Installed Fair 1953 9,942
HEART RIVER North Dakota Scour Critical — Countermeasures Installed Fair 1931 9,940
HCFCD DITCH Texas Scour Critical — Countermeasures Installed Fair 1979 9,939

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.