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
JOES CREEK Florida Scour Critical — Countermeasures Installed Good 1981 6,000
BLACK CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1967 6,000
WARES CREEK Florida Scour Critical — Countermeasures Installed Fair 1963 6,000
BRUSHY CREEK South Carolina Scour Critical — Countermeasures Installed Good 1977 6,000
SACRAMENTO RIVER California Scour Critical — Countermeasures Installed Poor 1975 6,000
SCHUYLKILL RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1932 5,993
CROCKERY CREEK Michigan Scour Critical — Countermeasures Installed Poor 1958 5,976
MT SCOTT CREEK Oregon Scour Critical — Countermeasures Installed Good 1970 5,974
MUDDY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1930 5,968
TENAKILL BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1955 5,968
SKIPPACK CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1932 5,958
MUSTANG BAYOU Texas Scour Critical — Countermeasures Installed Fair 2013 5,948
POND CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1940 5,948
WALNUT RIV & LOCAL RD Kansas Scour Critical — Countermeasures Installed Good 1939 5,944
OAK CR Oregon Scour Critical — Countermeasures Installed Fair 1978 5,930
N BRANCH RIVER New Hampshire Scour Critical — Countermeasures Installed Good 1988 5,929
METZLERS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1962 5,929
FURNACE HILL BROOK Rhode Island Scour Critical — Countermeasures Installed Fair 2000 5,919
DRAIN DTCH NO 1 Missouri Scour Critical — Countermeasures Installed Fair 1985 5,914
SYCAMORE CREEK Michigan Scour Critical — Countermeasures Installed Poor 1918 5,910
GEORGES CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1968 5,900
RIO CULEBRINAS Puerto Rico Scour Critical — Countermeasures Installed Poor 1901 5,900
CHANNEL Puerto Rico Scour Critical — Countermeasures Installed Fair 1966 5,900
MILL RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1936 5,900
DUCK CREEK Wisconsin Scour Critical — Countermeasures Installed Good 1975 5,900
SOUTHWICK CREEK Wisconsin Scour Critical — Countermeasures Installed Fair 1939 5,900
SUWANNEE RIVER Florida Scour Critical — Countermeasures Installed Fair 1989 5,900
SPRING CREEK Wisconsin Scour Critical — Countermeasures Installed Poor 1935 5,900
LEICESTER RIVER Vermont Scour Critical — Countermeasures Installed Fair 1943 5,900
CATFISH BRANCH South Carolina Scour Critical — Countermeasures Installed Poor 1941 5,900
MUD RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1932 5,877
THIRD RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1960 5,872
PUGET SOUND @ EDMONDS Washington Scour Critical — Countermeasures Installed Fair 1995 5,870
WISSAHICKON CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1884 5,864
HCFCD DITCH Texas Scour Critical — Countermeasures Installed Fair 1970 5,864
GRAND RIVER Michigan Scour Critical — Countermeasures Installed Poor 1966 5,860
PARSONS CREEK Oregon Scour Critical — Countermeasures Installed Fair 1978 5,859
LIGHTNING CREEK Kansas Scour Critical — Countermeasures Installed Good 1987 5,858
CROOKED CR Missouri Scour Critical — Countermeasures Installed Fair 1977 5,858
ARKANSAS RIVER Kansas Scour Critical — Countermeasures Installed Good 1973 5,858
ROCKAWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1928 5,854
CEDAR CREEK Washington Scour Critical — Countermeasures Installed Fair 1932 5,851
WABASH RIVER Indiana Scour Critical — Countermeasures Installed Fair 1992 5,848
MUSCONETCONG RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1932 5,846
PINE RIVER Michigan Scour Critical — Countermeasures Installed Poor 1952 5,845
TAMARACK CR Michigan Scour Critical — Countermeasures Installed Fair 1957 5,843
DARBY CREEK / 3476-F8 Pennsylvania Scour Critical — Countermeasures Installed Fair 1810 5,835
DRAINAGE DITCH Indiana Scour Critical — Countermeasures Installed Fair 1923 5,828
142 MILE CREEK Kansas Scour Critical — Countermeasures Installed Good 1956 5,825
142 MILE CREEK Kansas Scour Critical — Countermeasures Installed Fair 1956 5,825

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.