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
DUCK CRK Nevada Scour Critical — Countermeasures Installed Good 1974 12,000
DUCK CRK Nevada Scour Critical — Countermeasures Installed Good 1974 12,000
CULEBRINAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1979 12,000
TAYLORS RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1956 11,986
DIVERSION CANAL Louisiana Scour Critical — Countermeasures Installed Good 1989 11,969
BURNT RIVER(DIXIE CR) Oregon Scour Critical — Countermeasures Installed Fair 1971 11,968
KEARSLEY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1961 11,960
CLEAR FORK TRINITY RIVER Texas Scour Critical — Countermeasures Installed Fair 1951 11,958
BURNT RIVER (RR TUNNEL) Oregon Scour Critical — Countermeasures Installed Good 1971 11,958
CLEAR FORK TRINITY RIVER Texas Scour Critical — Countermeasures Installed Fair 1936 11,958
HAYES CREEK Michigan Scour Critical — Countermeasures Installed Good 1993 11,950
EAST BRANCH SNEECH BROOK Rhode Island Scour Critical — Countermeasures Installed Fair 1926 11,938
NODAWAY RVR Missouri Scour Critical — Countermeasures Installed Poor 1953 11,937
NORTH CR & GILLMAN TRAIL Washington Scour Critical — Countermeasures Installed Good 1968 11,919
N. BRANCH RANCOCAS CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1957 11,915
LACKAWANNA RIVER Pennsylvania Scour Critical — Countermeasures Installed Poor 1958 11,900
CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1945 11,900
BARRANQUITAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1908 11,900
THORNAPPLE RIVER Michigan Scour Critical — Countermeasures Installed Good 1930 11,887
COPLAY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1910 11,880
JACKSON BRANCH Texas Scour Critical — Countermeasures Installed Fair 1993 11,871
CYPRESS CREEK Texas Scour Critical — Countermeasures Installed Fair 1991 11,869
Bledsoe Creek Oregon Scour Critical — Countermeasures Installed Fair 1971 11,858
East Fork Dairy Creek Oregon Scour Critical — Countermeasures Installed Fair 1971 11,858
HAYWORTH COUNTY DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1988 11,851
HAYWORTH COUNTY DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1957 11,851
PRINCETON CANAL C-102 Florida Scour Critical — Countermeasures Installed Good 1965 11,850
HERSEY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1985 11,841
HERSEY CREEK Michigan Scour Critical — Countermeasures Installed Fair 1985 11,841
MILL CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1960 11,840
MILL CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1960 11,840
THIRD RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1963 11,837
MOREAU RVR OVERFLO Missouri Scour Critical — Countermeasures Installed Fair 1967 11,836
MOREAU RVR Missouri Scour Critical — Countermeasures Installed Poor 1967 11,836
HEMLOCK BROOK Rhode Island Scour Critical — Countermeasures Installed Fair 1926 11,806
STONEY BROOK Connecticut Scour Critical — Countermeasures Installed Good 1986 11,800
UP POAMOHO STRM-BRODIE 2 Hawaii Scour Critical — Countermeasures Installed Good 1937 11,800
EIGHT MILE BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1934 11,800
SAW MILL BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1951 11,800
Marys River Oregon Scour Critical — Countermeasures Installed Fair 1933 11,781
DRY CREEK California Scour Critical — Countermeasures Installed Good 1959 11,776
GROVE CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1928 11,770
PASSAIC RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1900 11,766
MCCOY WASH California Scour Critical — Countermeasures Installed Fair 1969 11,750
GALE DITCH California Scour Critical — Countermeasures Installed Fair 1969 11,750
MCCOY WASH California Scour Critical — Countermeasures Installed Fair 1969 11,750
PALOWALLA DITCH California Scour Critical — Countermeasures Installed Good 1969 11,750
PALOWALLA DITCH California Scour Critical — Countermeasures Installed Good 1969 11,750
ARKANSAS RIVER DRAINAGE Kansas Scour Critical — Countermeasures Installed Good 1967 11,739
CLINTON RIVER Michigan Scour Critical — Countermeasures Installed Poor 1960 11,736

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.