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
BALL CREEK Michigan Scour Critical — Countermeasures Installed Fair 1985 5,813
PORTER CREEK Oregon Scour Critical — Countermeasures Installed Good 1986 5,811
OX SWAMP South Carolina Scour Critical — Countermeasures Installed Good 2003 5,800
UNKNOWN WATERWAY Puerto Rico Scour Critical — Countermeasures Installed Fair 1980 5,800
TRIB TO ENOREE RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1965 5,800
NUEVE PASOS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1929 5,800
CHEPACHET RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1920 5,800
BRANCH APPLE CREEK Wisconsin Scour Critical — Countermeasures Installed Good 1997 5,800
SUWANNEE RIVER Florida Scour Critical — Countermeasures Installed Good 1971 5,800
WENATCHEE RIVER Washington Scour Critical — Countermeasures Installed Poor 1957 5,800
NORTH BR.NESHAMINY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1931 5,796
SYCAMORE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1975 5,795
PACIFIC P L TAILRACE Washington Scour Critical — Countermeasures Installed Good 1934 5,794
CLARKS RR PEMIGEWASSET R New Hampshire Scour Critical — Countermeasures Installed Good 1973 5,785
BUSH CREEK Michigan Scour Critical — Countermeasures Installed Fair 1960 5,784
TOBYS CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1970 5,783
ANTHRACITE CREEK Washington Scour Critical — Countermeasures Installed Poor 1940 5,782
CONTOOCOOK RIVER New Hampshire Scour Critical — Countermeasures Installed Poor 1942 5,773
COMITE RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1965 5,772
BONAPARTE CR Washington Scour Critical — Countermeasures Installed Good 1957 5,771
MILL CREEK Michigan Scour Critical — Countermeasures Installed Fair 1936 5,770
POLE CAT SLU Missouri Scour Critical — Countermeasures Installed Fair 1966 5,768
GOSHENHOPPEN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1954 5,768
RIPLEY CREEK Indiana Scour Critical — Countermeasures Installed Fair 1975 5,763
HUNTING CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1950 5,761
MACKVILLE CREEK Wisconsin Scour Critical — Countermeasures Installed Fair 1938 5,757
ST MARYS RIVER Indiana Scour Critical — Countermeasures Installed Poor 1972 5,750
RAFT RIVER Idaho Scour Critical — Countermeasures Installed Fair 1973 5,750
RAFT RIVER Idaho Scour Critical — Countermeasures Installed Fair 1967 5,750
S.FK.COEUR DALENE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1978 5,750
S.FK.COEUR DALENE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1978 5,750
ROCK RIVER Illinois Scour Critical — Countermeasures Installed Poor 1980 5,750
NEOSHO RIVER Kansas Scour Critical — Countermeasures Installed Fair 1987 5,746
HICKORY CREEK Kansas Scour Critical — Countermeasures Installed Good 1987 5,746
PARADISE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 5,745
DOWAGIAC RIVER Michigan Scour Critical — Countermeasures Installed Fair 1953 5,743
TEANAWAY R Washington Scour Critical — Countermeasures Installed Fair 1977 5,741
BEAR RIVER Maine Scour Critical — Countermeasures Installed Fair 1929 5,738
CHAMBERS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1977 5,736
WISSAHICKON CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1963 5,733
TAYLORS RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1928 5,723
NAVASOTA RIVER Texas Scour Critical — Countermeasures Installed Fair 1952 5,723
WHITEWATER RIVER Indiana Scour Critical — Countermeasures Installed Fair 1986 5,720
ANNA RIVER Michigan Scour Critical — Countermeasures Installed Fair 1978 5,715
BRANDYWINE CREEK Indiana Scour Critical — Countermeasures Installed Poor 1955 5,707
LITTLE BEAVER CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1938 5,703
ROGERS POND Connecticut Scour Critical — Countermeasures Installed Fair 1941 5,700
PATTEE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1939 5,700
WILLIAMS RIVER Vermont Scour Critical — Countermeasures Installed Good 1962 5,700
ARENAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1905 5,700

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.