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
SACONY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1911 7,077
PIDCOCK CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1935 7,075
NORTH RUN New Jersey Scour Critical — Countermeasures Installed Fair 1900 7,062
BIG BLUE RIVER Indiana Scour Critical — Countermeasures Installed Fair 1943 7,059
PASCACK BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1959 7,057
BOOTS CREEK Indiana Scour Critical — Countermeasures Installed Good 1994 7,055
SMOKY HILL RIVER Kansas Scour Critical — Countermeasures Installed Good 1966 7,050
SMOKY HILL RIVER Kansas Scour Critical — Countermeasures Installed Good 1966 7,050
MARTINS CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1911 7,047
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1962 7,042
BIG EAGLE CREEK Indiana Scour Critical — Countermeasures Installed Good 1993 7,040
SQUILCHUCK CREEK Washington Scour Critical — Countermeasures Installed Good 1954 7,038
Slate Run Creek Pennsylvania Scour Critical — Countermeasures Installed Fair 1978 7,037
Shark River New Jersey Scour Critical — Countermeasures Installed Fair 1932 7,029
LITTLE BUSHKILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1929 7,017
Granite Creek Arizona Scour Critical — Countermeasures Installed Fair 1921 7,000
COEUR DALENE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1964 7,000
HUERFANO RIVER Colorado Scour Critical — Countermeasures Installed Fair 1967 7,000
TROUT CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1965 7,000
COEUR DALENE RIVER Idaho Scour Critical — Countermeasures Installed Fair 1964 7,000
GUNNISON RIVER Colorado Scour Critical — Countermeasures Installed Fair 1980 7,000
S 5750;PINE CR;PINEHURST Idaho Scour Critical — Countermeasures Installed Fair 1965 7,000
WINTERGREEN BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1939 7,000
BRUSH HOLLOW CREEK Colorado Scour Critical — Countermeasures Installed Fair 1949 7,000
S 5750;PINE CR;PINEHURST Idaho Scour Critical — Countermeasures Installed Fair 1965 7,000
WEST BRANCH TROUT BROOK Connecticut Scour Critical — Countermeasures Installed Poor 1916 7,000
LAPWAI CREEK Idaho Scour Critical — Countermeasures Installed Fair 1964 7,000
LAPWAI CREEK Idaho Scour Critical — Countermeasures Installed Fair 1964 7,000
JOBITOS CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1958 7,000
CAT TAIL RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1956 6,999
BROAD RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1959 6,997
Small Wash Arizona Scour Critical — Countermeasures Installed Fair 1900 6,995
PROCTOR CREEK Washington Scour Critical — Countermeasures Installed Fair 1933 6,993
TRIB. SAUCON CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1953 6,993
SAUCON CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1927 6,993
CHERRY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1952 6,982
BITTERROOT RIVER Montana Scour Critical — Countermeasures Installed Fair 1949 6,979
DEER CREEK Michigan Scour Critical — Countermeasures Installed Poor 1920 6,976
RUSSIA BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1900 6,975
MILL CREEK New Jersey Scour Critical — Countermeasures Installed Poor 1930 6,971
Small Wash Arizona Scour Critical — Countermeasures Installed Fair 1938 6,968
LOUSE CREEK Oregon Scour Critical — Countermeasures Installed Fair 1974 6,962
E FORK WHITEWATER RIVER Indiana Scour Critical — Countermeasures Installed Fair 1992 6,960
FLAT FORK CREEK Texas Scour Critical — Countermeasures Installed Good 1935 6,957
RAMBIN BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 2000 6,956
BUCK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1931 6,954
KEEGANS BAYOU Texas Scour Critical — Countermeasures Installed Fair 1960 6,954
MILES PINE CREEK Florida Scour Critical — Countermeasures Installed Fair 1983 6,950
RICKEY DITCH OVERFLOW California Scour Critical — Countermeasures Installed Good 1965 6,950
FIVE MILE CREEK Texas Scour Critical — Countermeasures Installed Fair 1962 6,947

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.