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
PUGET SOUND @ SOUTHWORTH Washington Scour Critical — Countermeasures Installed Good 2003 3,681
Calapooia River Oregon Scour Critical — Countermeasures Installed Fair 1963 3,679
Town Branch Texas Scour Critical — Countermeasures Installed Fair 1935 3,678
EAST BRANCH COXES CREEK Pennsylvania Scour Critical — Countermeasures Installed Good 1956 3,675
M FORK WILDCAT CREEK Indiana Scour Critical — Countermeasures Installed Good 1993 3,675
HONEY CR DRAIN DTC Missouri Scour Critical — Countermeasures Installed Fair 1973 3,670
MUD CREEK Michigan Scour Critical — Countermeasures Installed Fair 1949 3,660
Mammoth Wash Arizona Scour Critical — Countermeasures Installed Fair 1956 3,653
TYLER CREEK Michigan Scour Critical — Countermeasures Installed Fair 1940 3,652
TRIB.TULPEHOCKEN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1928 3,651
SPANISH HOLLOW CREEK Oregon Scour Critical — Countermeasures Installed Fair 1963 3,651
SPANISH HOLLOW CREEK Oregon Scour Critical — Countermeasures Installed Fair 1963 3,651
SPANISH HOLLOW CREEK Oregon Scour Critical — Countermeasures Installed Fair 1963 3,651
WATER MOSS BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1909 3,651
SPANISH HOLLOW CREEK Oregon Scour Critical — Countermeasures Installed Fair 1963 3,651
WAGNER CR./TALENT AVE. Oregon Scour Critical — Countermeasures Installed Fair 1914 3,649
PINE KILL New York Scour Critical — Countermeasures Installed Poor 1928 3,645
BEARSKIN CREEK Wisconsin Scour Critical — Countermeasures Installed Poor 1932 3,642
LITTLE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1985 3,639
WHITMORE DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1956 3,633
TURKEY CREEK Indiana Scour Critical — Countermeasures Installed Fair 1957 3,632
BEAVER DAM CREEK New York Scour Critical — Countermeasures Installed Good 1994 3,631
SONOMA CREEK California Scour Critical — Countermeasures Installed Fair 1929 3,628
BITTERROOT RIVER 010 Montana Scour Critical — Countermeasures Installed Fair 1935 3,627
WILLOW CREEK Oregon Scour Critical — Countermeasures Installed Fair 1971 3,627
ARKANSAS RIVER Kansas Scour Critical — Countermeasures Installed Good 1980 3,622
BIG CREEK Kansas Scour Critical — Countermeasures Installed Fair 1966 3,622
AROOSTOOK RIV ABANDD RR Maine Scour Critical — Countermeasures Installed Poor 1956 3,620
C STREET CANAL Kansas Scour Critical — Countermeasures Installed Fair 1950 3,620
MILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1947 3,617
NINEMILE CREEK New York Scour Critical — Countermeasures Installed Fair 1966 3,616
MUSKEGON RIVER Michigan Scour Critical — Countermeasures Installed Fair 1977 3,615
MILL CANAL Rhode Island Scour Critical — Countermeasures Installed Good 2018 3,603
ARKANSAS RIVER Kansas Scour Critical — Countermeasures Installed Fair 1961 3,602
FIRE PRAIRIE CR Missouri Scour Critical — Countermeasures Installed Poor 1984 3,602
JAMES RV South Dakota Scour Critical — Countermeasures Installed Poor 1960 3,601
SINCLAIR INLET Washington Scour Critical — Countermeasures Installed Fair 1990 3,600
CREEK Puerto Rico Scour Critical — Countermeasures Installed Good 1965 3,600
CREEK Puerto Rico Scour Critical — Countermeasures Installed Good 1965 3,600
ROCK CREEK Arkansas Scour Critical — Countermeasures Installed Fair 1953 3,600
MIRAFLORES CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1929 3,600
SOLOMON CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1950 3,600
DUEY RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1949 3,600
TRIB TO PACOLET RIVER South Carolina Scour Critical — Countermeasures Installed Fair 1973 3,600
UNNAMED CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1950 3,600
CARMEL RIVER California Scour Critical — Countermeasures Installed Good 1971 3,600
PORTER SLOUGH California Scour Critical — Countermeasures Installed Good 1937 3,600
LA PLATA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1991 3,600
CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1976 3,600
HIGUERO CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1986 3,600

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.