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
WATER MILL BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1920 2,800
ROCKY CREEK South Carolina Scour Critical — Countermeasures Installed Poor 1962 2,800
MIDDLE BRANCH BUSHY CK South Carolina Scour Critical — Countermeasures Installed Fair 1982 2,800
SNAKE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1967 2,800
SHAMONA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1965 2,800
SANTA CATALINA CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1980 2,800
SALKEHATCHIE RIVER SWAMP South Carolina Scour Critical — Countermeasures Installed Fair 2002 2,800
GUAMANI RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1925 2,800
TRIB TO KEOWEE RIVER South Carolina Scour Critical — Countermeasures Installed Poor 1958 2,800
BURNT FORK West Virginia Scour Critical — Countermeasures Installed Poor 1959 2,800
TRIB TO RICES CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1967 2,800
SANTANA CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1900 2,800
FIFTEEN MILE CREEK South Carolina Scour Critical — Countermeasures Installed Poor 1965 2,800
MORGAN CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1922 2,800
BEAR RIVER;RIVERDALE BR Idaho Scour Critical — Countermeasures Installed Fair 1960 2,800
WHIPPY SWAMP South Carolina Scour Critical — Countermeasures Installed Good 2002 2,800
BRANNIN CREEK California Scour Critical — Countermeasures Installed Poor 1914 2,799
RICE CREEK California Scour Critical — Countermeasures Installed Fair 1914 2,799
CLEAR CREEK Indiana Scour Critical — Countermeasures Installed Fair 1988 2,798
OVER SPRUCE RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1948 2,792
LITTLE QUILCENE RIVER Washington Scour Critical — Countermeasures Installed Fair 1938 2,792
ALLOWAYS CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1930 2,787
RHINEBECK KILL New York Scour Critical — Countermeasures Installed Poor 1919 2,787
WATER NASKETUCKET BAY Massachusetts Scour Critical — Countermeasures Installed Fair 1920 2,785
EAGLE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1952 2,781
E BRANCH NAUGATUCK RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1961 2,780
CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1954 2,778
BULL BRANCH Louisiana Scour Critical — Countermeasures Installed Poor 1957 2,778
WEST BRANCH RUSSIAN RIV California Scour Critical — Countermeasures Installed Poor 1958 2,776
OVER LITTLE SUGAR CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1985 2,773
OVER LITTLE SUGAR CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1985 2,773
ASSISCONG CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1923 2,771
DRY CREEK California Scour Critical — Countermeasures Installed Fair 1987 2,769
PUCHYAN RIVER Wisconsin Scour Critical — Countermeasures Installed Poor 1929 2,769
BUCK RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 2,763
ALEXANDER CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1948 2,761
WATNONG BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1944 2,761
MARAIS DES CYGNES RIVER Kansas Scour Critical — Countermeasures Installed Fair 1973 2,760
SPRING GARDEN BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1936 2,760
S BR CASS RIVER I/C DRN Michigan Scour Critical — Countermeasures Installed Poor 1930 2,754
SCATTER CREEK Washington Scour Critical — Countermeasures Installed Fair 1965 2,751
SUGAR CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1919 2,748
SUGAR CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1923 2,748
SUGAR CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1919 2,748
SUGAR CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1923 2,748
LONG TOM RIVER Oregon Scour Critical — Countermeasures Installed Fair 1978 2,746
PIPE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1942 2,741
SHILOH BRANCH Texas Scour Critical — Countermeasures Installed Fair 1990 2,735
LITTLE ANDERSON CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1921 2,732
THORNAPPLE RIVER Michigan Scour Critical — Countermeasures Installed Good 1970 2,730

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.