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
PICKERING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1969 7,961
MOSHASSUCK RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1916 7,957
PERKIOMEN CREEK/2917-D9 Pennsylvania Scour Critical — Countermeasures Installed Fair 1967 7,957
LONE ROCK CK South Dakota Scour Critical — Countermeasures Installed Fair 1959 7,955
PLATTE OVERFLOW Nebraska Scour Critical — Countermeasures Installed Fair 1955 7,955
LONE ROCK CK South Dakota Scour Critical — Countermeasures Installed Fair 1959 7,955
TRUCKEE RIVER Nevada Scour Critical — Countermeasures Installed Fair 1966 7,950
TRUCKEE RIVER Nevada Scour Critical — Countermeasures Installed Fair 1966 7,950
LITTLE GRAVOIS CR Missouri Scour Critical — Countermeasures Installed Good 1966 7,947
FISHING CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1910 7,944
PLUM CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1956 7,943
BOOTS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1926 7,943
HICKS CREEK Texas Scour Critical — Countermeasures Installed Fair 1942 7,939
RIDLEY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 7,934
LITTLE GRAVOIS CR Missouri Scour Critical — Countermeasures Installed Fair 1966 7,933
FRENCH CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1959 7,931
STEELE BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1963 7,900
BEAR CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1970 7,900
MANATAWNY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1951 7,884
Ash Creek Oregon Scour Critical — Countermeasures Installed Fair 1981 7,883
SOUTH UMPQUA OVERFLOW Oregon Scour Critical — Countermeasures Installed Good 1963 7,879
SLATE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1927 7,878
BUTCHER KNIFE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1927 7,878
SLATE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1927 7,878
WATERS CREEK Oregon Scour Critical — Countermeasures Installed Fair 1927 7,878
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1979 7,875
3 MILE BRANCH Illinois Scour Critical — Countermeasures Installed Fair 1974 7,850
WOONASQUATUCKET RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1979 7,850
Plympton Creek Oregon Scour Critical — Countermeasures Installed Fair 1958 7,845
MATTAWOMAN CREEK Maryland Scour Critical — Countermeasures Installed Fair 1984 7,843
LABETTE CREEK Kansas Scour Critical — Countermeasures Installed Good 1937 7,842
POST OAK CREEK Texas Scour Critical — Countermeasures Installed Fair 1933 7,826
TRIBUTARY TO SEVERN RUN Maryland Scour Critical — Countermeasures Installed Fair 1988 7,820
WATER QUINEBAUG RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1938 7,817
GRIFFIN CR Washington Scour Critical — Countermeasures Installed Fair 1945 7,813
WILLOW CREEK Texas Scour Critical — Countermeasures Installed Good 1980 7,803
BLACKSTONE RVR P&W BP Rhode Island Scour Critical — Countermeasures Installed Fair 2021 7,800
TACITO CREEK Florida Scour Critical — Countermeasures Installed Fair 1991 7,800
HURRICANE CREEK Arkansas Scour Critical — Countermeasures Installed Fair 1950 7,800
SALTO ABAJO CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1892 7,800
CA¥ABONCITO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1989 7,800
NAUGATUCK RIVER Connecticut Scour Critical — Countermeasures Installed Poor 1959 7,800
CA¥ABONCITO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1930 7,800
HAW RIVER & SO. RAILWAY North Carolina Scour Critical — Countermeasures Installed Fair 1990 7,800
CICERO CREEK (MORSE RES) Indiana Scour Critical — Countermeasures Installed Fair 1953 7,800
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Fair 1989 7,800
GURABO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1980 7,800
BRANDYWINE CREEK FLOOD Pennsylvania Scour Critical — Countermeasures Installed Good 1912 7,797
BRANDYWINE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1902 7,797
ROCK CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1966 7,783

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.