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
CREEK Louisiana Scour Critical — Countermeasures Installed Good 1966 3,768
TANGIPAHOA RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1966 3,768
CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1966 3,768
COLUMBIA R Washington Scour Critical — Countermeasures Installed Fair 1970 3,767
OVER SWAMP RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1955 3,762
GORDONS CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1925 3,757
Patterson Wash Arizona Scour Critical — Countermeasures Installed Fair 1932 3,757
SNAKE RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1980 3,750
HILLSBOROUGH RIVER Florida Scour Critical — Countermeasures Installed Fair 1963 3,747
LANDSMAN KILL New York Scour Critical — Countermeasures Installed Fair 1933 3,746
EAST CANYON CREEK Utah Scour Critical — Countermeasures Installed Fair 1952 3,743
INLET TO SNAG POND Pennsylvania Scour Critical — Countermeasures Installed Fair 1984 3,742
LAMB CREEK Michigan Scour Critical — Countermeasures Installed Fair 1959 3,741
MCLAUGHLIN RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1900 3,740
TRIB TO ROARING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1959 3,739
MONTGOMERY DITCH Indiana Scour Critical — Countermeasures Installed Fair 1953 3,733
JONES BEND CREEK Tennessee Scour Critical — Countermeasures Installed Good 1930 3,729
ROBINSONS BRANCH RAH RIV New Jersey Scour Critical — Countermeasures Installed Fair 1921 3,725
Boulder Creek Oregon Scour Critical — Countermeasures Installed Fair 1932 3,723
MAPLE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1989 3,723
DEEDS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1947 3,722
BRAZOS RIVER Texas Scour Critical — Countermeasures Installed Fair 1969 3,720
POCOTOPAUG CREEK Connecticut Scour Critical — Countermeasures Installed Good 2009 3,718
GATE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1930 3,712
SCHLEGEL RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1933 3,711
N FK CROW RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1941 3,710
POHOPOCO CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1918 3,709
ELLIS CREEK New York Scour Critical — Countermeasures Installed Fair 1931 3,708
TRIB.TO MILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1932 3,704
LONG BRANCH Florida Scour Critical — Countermeasures Installed Fair 1950 3,700
MUZZLE FORK West Virginia Scour Critical — Countermeasures Installed Poor 1936 3,700
PALMAS CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1923 3,700
CONOCOCHEAGUE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1828 3,700
SOUTH SALUDA RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1970 3,700
CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1950 3,700
WARRIOR RIVER RELIEF Alabama Scour Critical — Countermeasures Installed Fair 1941 3,700
WABASH RIVER Illinois Scour Critical — Countermeasures Installed Fair 1956 3,700
BR OF UNAMI CREEK/2806G3 Pennsylvania Scour Critical — Countermeasures Installed Poor 1951 3,699
CHEWUCH RIVER Washington Scour Critical — Countermeasures Installed Poor 1961 3,696
QUEMAHONING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1949 3,695
BRANCH POLSON CREEK Indiana Scour Critical — Countermeasures Installed Fair 1983 3,694
NEWAUKUM CREEK Washington Scour Critical — Countermeasures Installed Fair 1927 3,694
CHIPPEWA RIVER Michigan Scour Critical — Countermeasures Installed Fair 1961 3,694
JONES CREEK Michigan Scour Critical — Countermeasures Installed Fair 1928 3,691
BAYOU LACOMBE Louisiana Scour Critical — Countermeasures Installed Fair 1953 3,690
BOGUE FALAYA RELIEF Louisiana Scour Critical — Countermeasures Installed Fair 1978 3,689
PIGEON ROOST CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1980 3,689
BOGUE FALAYA RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1978 3,689
Gila River Arizona Scour Critical — Countermeasures Installed Good 1988 3,688
LITTLE CACOOSING CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1942 3,682

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.