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
BROOKHOLLOW CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1975 19,279
Spring Creek-Springdale Arkansas Scour Critical — Countermeasures Installed Fair 2008 19,275
MONTGOMERY CREEK Indiana Scour Critical — Countermeasures Installed Fair 1965 19,260
POTRERO CREEK California Scour Critical — Countermeasures Installed Fair 1926 19,252
ARROYO DEL VALLE California Scour Critical — Countermeasures Installed Poor 1940 19,250
MUDDY RIVER Nevada Scour Critical — Countermeasures Installed Fair 1962 19,250
MUDDY RIVER Nevada Scour Critical — Countermeasures Installed Fair 1962 19,250
MANADAS CREEK TRIBUTARY Texas Scour Critical — Countermeasures Installed Good 1998 19,242
CHANNEL Puerto Rico Scour Critical — Countermeasures Installed Poor 1980 19,200
COLES BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1931 19,200
CONNECTICUT RIVER NECRR Vermont Scour Critical — Countermeasures Installed Poor 1966 19,185
MUCKINIPATTUS CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1925 19,177
NS RR MCCULLOCH DITCH Indiana Scour Critical — Countermeasures Installed Fair 1964 19,158
WILSON CREEK RELIEF Texas Scour Critical — Countermeasures Installed Fair 1957 19,136
BOWLEES CREEK Florida Scour Critical — Countermeasures Installed Good 1989 19,100
ROGUE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1960 19,047
CREEK Oregon Scour Critical — Countermeasures Installed Fair 1961 19,034
CREEK Oregon Scour Critical — Countermeasures Installed Good 1956 19,034
KINNICKINNICK RIVER Wisconsin Scour Critical — Countermeasures Installed Poor 1987 19,025
JOHNSON FK/JOHNSON FK RD Indiana Scour Critical — Countermeasures Installed Good 1960 19,024
IVANPAH DITCH California Scour Critical — Countermeasures Installed Good 1963 19,000
YANTIC RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1959 19,000
BRANCH WISSAHICKON CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1957 18,982
SWAMP CREEK Washington Scour Critical — Countermeasures Installed Fair 1935 18,981
DUCK CREEK Texas Scour Critical — Countermeasures Installed Fair 1952 18,979
JOHNSON FK/JOHNSON FK RD Indiana Scour Critical — Countermeasures Installed Fair 1960 18,929
MT HP BY N SEC RR 114 LP Rhode Island Scour Critical — Countermeasures Installed Fair 1929 18,924
MANOA-PALOLO STRM Hawaii Scour Critical — Countermeasures Installed Good 1950 18,917
ARKANSAS RIVER Kansas Scour Critical — Countermeasures Installed Fair 1966 18,907
COCAL RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1959 18,900
NIGUA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1971 18,900
SADDLE RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1922 18,844
NOLANDS FORK Indiana Scour Critical — Countermeasures Installed Good 1959 18,841
RABBIT RIVER Michigan Scour Critical — Countermeasures Installed Fair 1957 18,817
UNAMI CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1965 18,805
NORWALK RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1928 18,800
NS RR MCCULLOCH DITCH Indiana Scour Critical — Countermeasures Installed Fair 1964 18,794
WHITE CLAY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1927 18,776
Canal 100-A Florida Scour Critical — Countermeasures Installed Poor 1966 18,758
JEFFERIES CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1966 18,750
TRUCKEE RIVER & SPRR Nevada Scour Critical — Countermeasures Installed Fair 1964 18,750
TRUCKEE RIVER & SPRR Nevada Scour Critical — Countermeasures Installed Fair 1964 18,750
THOMPSON RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1959 18,741
SYMONS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1965 18,703
SYMONS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1965 18,703
E FK/E FK WHITEWATER RIV Indiana Scour Critical — Countermeasures Installed Poor 1959 18,702
WILSON CREEK RELIEF Texas Scour Critical — Countermeasures Installed Fair 1957 18,700
GREENS BAYOU Texas Scour Critical — Countermeasures Installed Fair 1986 18,696
GRANNEYS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1979 18,687
BRANCH SHABAKUNK CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1950 18,625

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.