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
TURNERS CREEK Florida Scour Critical — Countermeasures Installed Fair 1963 15,000
WATER EAST RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1914 15,000
FRANK & POET DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1936 14,984
BRANCH PENNYPACK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1967 14,968
ROCKAWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1954 14,953
SEEKONK RVR TAFT S Rhode Island Scour Critical — Countermeasures Installed Fair 1877 14,948
PINE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1977 14,925
GRAND RIVER & MARKET RD Michigan Scour Critical — Countermeasures Installed Fair 1959 14,899
GRAND RIVER & MARKET ST Michigan Scour Critical — Countermeasures Installed Fair 1959 14,899
RED RUN DRAIN Michigan Scour Critical — Countermeasures Installed Poor 1985 14,852
FELLOWS CREEK Michigan Scour Critical — Countermeasures Installed Poor 1930 14,842
MILL-RACE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1929 14,824
ECORSE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1977 14,820
BRANCH PENNYPACK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1941 14,809
BRANCH DELAWARE RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1942 14,803
LITTLE RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1933 14,800
BRUSH HEAP CREEK Indiana Scour Critical — Countermeasures Installed Fair 1974 14,800
AIRPORT SLOUGH Nevada Scour Critical — Countermeasures Installed Fair 1965 14,800
BRONX RIVER New York Scour Critical — Countermeasures Installed Fair 1923 14,760
WHITE RIVER Indiana Scour Critical — Countermeasures Installed Fair 1936 14,760
SCHUYLKILL RIV;NSRC;ROAD Pennsylvania Scour Critical — Countermeasures Installed Fair 1924 14,759
NAPA RIVER California Scour Critical — Countermeasures Installed Fair 1960 14,755
PILARCITOS CREEK California Scour Critical — Countermeasures Installed Good 1954 14,750
WACCAMAW RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1986 14,750
PILARCITOS CREEK California Scour Critical — Countermeasures Installed Fair 1954 14,750
TROUBLESOME CREEK North Carolina Scour Critical — Countermeasures Installed Fair 1968 14,750
WACCAMAW RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1986 14,750
TEN MILE RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1921 14,747
PINE RUN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1915 14,723
TEMESCAL WASH California Scour Critical — Countermeasures Installed Fair 1983 14,721
GUN RIVER Michigan Scour Critical — Countermeasures Installed Fair 1960 14,700
GUN RIVER Michigan Scour Critical — Countermeasures Installed Fair 1960 14,700
CATAÑO CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1928 14,700
GURABO RIVER KM 20.41 Puerto Rico Scour Critical — Countermeasures Installed Fair 1955 14,700
TRIB.WILLOW CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1955 14,685
PECKMAN RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1913 14,684
ABITA RIVER Louisiana Scour Critical — Countermeasures Installed Good 1975 14,668
PROVO RIVER Utah Scour Critical — Countermeasures Installed Fair 1960 14,608
MERCADO CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1952 14,600
LITTLE RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1926 14,600
BR.LITTLE NESHAMINY CR. Pennsylvania Scour Critical — Countermeasures Installed Fair 1923 14,595
BYRAM RIVER New York Scour Critical — Countermeasures Installed Poor 1926 14,570
PRAIRIE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1959 14,559
KALIHI STRM Hawaii Scour Critical — Countermeasures Installed Fair 1927 14,551
Middle Creek Ash Creek Oregon Scour Critical — Countermeasures Installed Fair 1954 14,546
NONCONNAH CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1980 14,539
PRAIRIE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1951 14,533
CRUM CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1949 14,523
SAN JACINTO RIVER Texas Scour Critical — Countermeasures Installed Fair 1968 14,511
LITTLE NORTHEAST North Carolina Scour Critical — Countermeasures Installed Fair 1994 14,500

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.