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
RAHWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1914 25,190
SUGAR CREEK Indiana Scour Critical — Countermeasures Installed Fair 1963 25,145
CLEAR CREEK Indiana Scour Critical — Countermeasures Installed Good 1964 25,145
CLEAR CREEK Indiana Scour Critical — Countermeasures Installed Good 1964 25,145
DOCTORS CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1951 25,095
SOUTH BR RARITAN RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1921 25,056
ROCK CREEK Oregon Scour Critical — Countermeasures Installed Fair 1953 25,052
KALIHI STRM Hawaii Scour Critical — Countermeasures Installed Fair 1933 25,033
AIRES CANAL Florida Scour Critical — Countermeasures Installed Good 1999 25,000
COMB MERIMAC RIV/ACCESS Massachusetts Scour Critical — Countermeasures Installed Fair 1918 25,000
LITTLE WHITE LICK CREEK Indiana Scour Critical — Countermeasures Installed Fair 1976 24,998
LITTLE WHITE LICK CREEK Indiana Scour Critical — Countermeasures Installed Fair 1976 24,998
BLAKLEY DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1986 24,955
DUCK RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1947 24,920
DUCK RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1948 24,920
BIG COTTONWOOD CREEK Texas Scour Critical — Countermeasures Installed Poor 1929 24,909
WALTON CREEK Texas Scour Critical — Countermeasures Installed Fair 1949 24,899
BLACK CREEK Georgia Scour Critical — Countermeasures Installed Good 1966 24,800
SKOOKUMCHUCK RIVER Washington Scour Critical — Countermeasures Installed Fair 1951 24,769
SKOOKUMCHUCK RIVER Washington Scour Critical — Countermeasures Installed Fair 1951 24,769
LITTLE CHIQUES CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1968 24,666
PIEDRAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1989 24,600
KALAMAZOO RIVER Michigan Scour Critical — Countermeasures Installed Fair 1966 24,600
KEEGANS BAYOU Texas Scour Critical — Countermeasures Installed Good 1988 24,543
SNAKE R;FRUITLAND BRIDGE Idaho Scour Critical — Countermeasures Installed Good 1967 24,500
NACHES RIVER Washington Scour Critical — Countermeasures Installed Fair 1932 24,488
Conewago Creek Pennsylvania Scour Critical — Countermeasures Installed Fair 1949 24,423
Yamhill River Overflow Oregon Scour Critical — Countermeasures Installed Fair 1963 24,417
KALAMAZOO RIVER Michigan Scour Critical — Countermeasures Installed Fair 1964 24,400
PINE BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1921 24,340
COLES BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1962 24,330
ASSISCUNK CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1963 24,327
BIG WATEREE CK South Carolina Scour Critical — Countermeasures Installed Fair 1979 24,300
BIG WATEREE CK South Carolina Scour Critical — Countermeasures Installed Fair 1979 24,300
ASSISCUNK CREEK New Jersey Scour Critical — Countermeasures Installed Poor 1935 24,298
WILLOUGHBY BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1930 24,297
SR 10 RL / ELK RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1968 24,286
SNI-A-BAR CR Missouri Scour Critical — Countermeasures Installed Fair 1948 24,233
SOUTHAMPTON CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1966 24,196
KALAMAZOO RIVER Michigan Scour Critical — Countermeasures Installed Good 2024 24,126
JEFFERIES CREEK South Carolina Scour Critical — Countermeasures Installed Poor 1938 24,100
BIG DRY CREEK Colorado Scour Critical — Countermeasures Installed Fair 1970 24,040
ASH CREEK Oregon Scour Critical — Countermeasures Installed Fair 1989 24,002
LOTTS CREEK Georgia Scour Critical — Countermeasures Installed Good 1976 23,900
HARRISONS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1971 23,883
Willow Brook New Jersey Scour Critical — Countermeasures Installed Fair 1968 23,861
GOODBYS LAKE Florida Scour Critical — Countermeasures Installed Fair 1967 23,750
OYSTER CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1967 23,730
ORE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1940 23,661
ORE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1959 23,661

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.