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
Johnson Creek Oregon Scour Critical — Countermeasures Installed Fair 1991 45,032
NASSAU RIVER Florida Scour Critical — Countermeasures Installed Poor 1967 45,000
NASSAU RIVER Florida Scour Critical — Countermeasures Installed Poor 1967 45,000
LICK CREEK Indiana Scour Critical — Countermeasures Installed Good 1963 44,678
MAHORAS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1928 44,635
NESHAMINY CR & APPL 276 Pennsylvania Scour Critical — Countermeasures Installed Fair 1964 44,629
PIEDRAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1950 44,600
Willamette River Oregon Scour Critical — Countermeasures Installed Fair 1953 44,573
MONOCACY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1941 44,528
BIG BRANCH Louisiana Scour Critical — Countermeasures Installed Good 1969 44,252
BLOOD RIVER Louisiana Scour Critical — Countermeasures Installed Fair 1968 44,252
COOLEY BRANCH Louisiana Scour Critical — Countermeasures Installed Good 1960 44,225
COOLEY BRANCH Louisiana Scour Critical — Countermeasures Installed Fair 1960 44,225
BOND CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1929 44,043
Mill Creek Oregon Scour Critical — Countermeasures Installed Fair 1956 43,693
WATER FISH BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1950 43,600
INDIAN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1961 43,502
WATER FISH BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1976 43,300
SAW MILL RIVER New York Scour Critical — Countermeasures Installed Poor 1927 43,153
WOLF CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1957 43,065
SAW MILL RIVER New York Scour Critical — Countermeasures Installed Fair 1933 42,645
CENTRAL OREGON CANAL Oregon Scour Critical — Countermeasures Installed Fair 1966 42,538
GILLS CREEK South Carolina Scour Critical — Countermeasures Installed Good 1982 42,500
GILLS CREEK South Carolina Scour Critical — Countermeasures Installed Good 1982 42,500
SAW MILL RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1926 42,292
RAHWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1941 42,130
RAHWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1917 42,130
OAKEYS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1934 42,085
Loxahatchee River Florida Scour Critical — Countermeasures Installed Fair 1975 42,000
E FORK LEWIS RIVER Washington Scour Critical — Countermeasures Installed Poor 1939 41,939
LITTLE OGEECHEE RIVER Georgia Scour Critical — Countermeasures Installed Good 1966 41,900
PILCHUCK CREEK Washington Scour Critical — Countermeasures Installed Good 1973 41,822
PILCHUCK CREEK Washington Scour Critical — Countermeasures Installed Good 1954 41,822
CUB CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1960 41,499
CUB CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1960 41,499
TOBY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1963 41,421
TOBESOFKEE CREEK Georgia Scour Critical — Countermeasures Installed Good 1970 41,400
LANGHAM CREEK Texas Scour Critical — Countermeasures Installed Fair 1981 41,301
CYPRESS CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1959 41,152
CYPRESS CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1959 41,152
SWIFT CREEK North Carolina Scour Critical — Countermeasures Installed Fair 1966 41,000
SWIFT CREEK North Carolina Scour Critical — Countermeasures Installed Fair 1966 41,000
US 202 & RAMAPO RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1932 41,000
INDIAN CREEK CANAL Florida Scour Critical — Countermeasures Installed Poor 1953 41,000
MANATEE RIVER Florida Scour Critical — Countermeasures Installed Fair 1986 41,000
MACOPIN RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1924 40,996
MILL CREEK Oregon Scour Critical — Countermeasures Installed Fair 1929 40,878
MILL CREEK Oregon Scour Critical — Countermeasures Installed Fair 1949 40,878
BAYLISS STATE DITCH Indiana Scour Critical — Countermeasures Installed Fair 1966 40,874
BAYLISS STATE DITCH Indiana Scour Critical — Countermeasures Installed Fair 1966 40,874

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.