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
BIG FIERY GIZZARD CREEK Tennessee Scour Critical — Countermeasures Installed Good 1963 36,821
S BR ROCKAWAY CREEK New Jersey Scour Critical — Countermeasures Installed Good 1912 36,773
ORTEGA RIVER Florida Scour Critical — Countermeasures Installed Fair 1969 36,750
ORTEGA RIVER Florida Scour Critical — Countermeasures Installed Fair 1969 36,750
BLACK CREEK Georgia Scour Critical — Countermeasures Installed Good 1966 36,600
LYLE CREEK North Carolina Scour Critical — Countermeasures Installed Fair 1957 36,500
Cave Creek Arizona Scour Critical — Countermeasures Installed Fair 1976 36,376
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1962 36,373
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1962 36,373
BR OF SAND CREEK Michigan Scour Critical — Countermeasures Installed Good 1961 36,338
CLINTON R Michigan Scour Critical — Countermeasures Installed Fair 1929 36,241
BUFFALO BAYOU Texas Scour Critical — Countermeasures Installed Fair 1962 36,165
BEAR CREEK Oregon Scour Critical — Countermeasures Installed Fair 1961 36,121
ROCKY BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1936 35,803
QUINNIPIAC RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1946 35,800
SADDLE RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1923 35,582
SEALS GULLY Texas Scour Critical — Countermeasures Installed Fair 1986 35,579
N. CHICKAMAUGA CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1975 35,457
N. CHICKAMAUGA CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1975 35,457
MALAPARDIS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1932 35,424
BUFFALO RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1964 35,368
BUFFALO RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1964 35,368
SWEETWATER CREEK Florida Scour Critical — Countermeasures Installed Fair 1973 35,300
BRANCH NESHAMINY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1937 35,170
MORGAN CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1936 35,087
WILLAMETTE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1926 35,000
DISMAL SWAMP CANAL Virginia Scour Critical — Countermeasures Installed Poor 1934 35,000
COULEE MINE Louisiana Scour Critical — Countermeasures Installed Fair 1967 34,877
LICK RUN Indiana Scour Critical — Countermeasures Installed Fair 1992 34,755
MAMEYES RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1982 34,700
JORDAN RIVER Utah Scour Critical — Countermeasures Installed Fair 1966 34,656
MILLSTONE RIVER New Jersey Scour Critical — Countermeasures Installed Poor 1915 34,650
IRRIGATION DITCH Puerto Rico Scour Critical — Countermeasures Installed Good 1960 34,600
LITTLE BLACK CREEK Florida Scour Critical — Countermeasures Installed Poor 1947 34,500
WEST COLYELL CR Louisiana Scour Critical — Countermeasures Installed Good 1962 34,245
JACOBS CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1939 34,232
BIG WALNUT CREEK Indiana Scour Critical — Countermeasures Installed Fair 1966 34,117
BIG WALNUT CREEK Indiana Scour Critical — Countermeasures Installed Fair 1966 34,117
ACCESS ROAD SILVER CR. Indiana Scour Critical — Countermeasures Installed Fair 1972 34,076
JACOBS CREEK Indiana Scour Critical — Countermeasures Installed Fair 1972 34,076
INDIAN BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1962 33,925
CLEAR BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1962 33,925
DRY BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1962 33,925
MIDDLE SLOUGH Louisiana Scour Critical — Countermeasures Installed Fair 1962 33,925
YELLOW BAYOU Louisiana Scour Critical — Countermeasures Installed Fair 1962 33,925
WATER MERRIMACK RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1925 33,900
KEANANOIO STRM (O.B) Hawaii Scour Critical — Countermeasures Installed Fair 1967 33,900
MULBERRY CREEK Georgia Scour Critical — Countermeasures Installed Good 1978 33,700
QUINNIPIAC RIVER Connecticut Scour Critical — Countermeasures Installed Poor 1946 33,700
AMAZON CREEK Oregon Scour Critical — Countermeasures Installed Good 1977 33,645

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.