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
SMITH BROOK Vermont Scour Critical — Countermeasures Installed Fair 1945 5,700
ARENAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1905 5,700
TRAVERS CREEK California Scour Critical — Countermeasures Installed Fair 1936 5,700
WILLIAMS RIVER Vermont Scour Critical — Countermeasures Installed Good 1962 5,700
ROGERS POND Connecticut Scour Critical — Countermeasures Installed Fair 1941 5,700
PATTEE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1939 5,700
TURTLE CREEK Minnesota Scour Critical — Countermeasures Installed Fair 1957 5,698
ROCK RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1965 5,696
ROCK RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1965 5,696
A2 CHANNEL Oregon Scour Critical — Countermeasures Installed Good 1993 5,694
CREEK Washington Scour Critical — Countermeasures Installed Fair 1998 5,692
SHEPARD BROOK & RR TRAIL Connecticut Scour Critical — Countermeasures Installed Fair 1991 5,690
GREEN BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1929 5,689
PROVIDENCE RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1994 5,684
LITTLE BUTTE CREEK Oregon Scour Critical — Countermeasures Installed Good 2005 5,681
SATILLA RIVER Georgia Scour Critical — Countermeasures Installed Good 1964 5,680
SMACKOVER CREEK Arkansas Scour Critical — Countermeasures Installed Fair 1974 5,679
SHINNECOCK BAY New York Scour Critical — Countermeasures Installed Fair 1988 5,676
SPRING CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1926 5,674
E Branch Brawley Wash Arizona Scour Critical — Countermeasures Installed Fair 1957 5,668
FANNO CREEK Oregon Scour Critical — Countermeasures Installed Poor 1958 5,667
Devils Lake Fk Wilson R Oregon Scour Critical — Countermeasures Installed Fair 1940 5,662
SQUIRES CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1982 5,661
SEELYE BROOK Minnesota Scour Critical — Countermeasures Installed Poor 1984 5,661
CAMPBELL CREEK SB RAMP Alaska Scour Critical — Countermeasures Installed Good 1981 5,660
TRIB. TO COON CREEK Kansas Scour Critical — Countermeasures Installed Fair 1962 5,660
BEAR CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1977 5,659
SPRING CREEK Tennessee Scour Critical — Countermeasures Installed Poor 1930 5,658
KANSAS RIVER & RAILROAD Kansas Scour Critical — Countermeasures Installed Good 1970 5,657
HAZEN CREEK Michigan Scour Critical — Countermeasures Installed Fair 1978 5,656
Outfall Canal Louisiana Scour Critical — Countermeasures Installed Good 2010 5,650
Fallout Canal Louisiana Scour Critical — Countermeasures Installed Good 2010 5,650
SHORT CREEK Indiana Scour Critical — Countermeasures Installed Fair 1986 5,648
SHIAWASSEE RIVER Michigan Scour Critical — Countermeasures Installed Poor 1928 5,647
SPAULDING DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1940 5,643
SPAULDING DRAIN Michigan Scour Critical — Countermeasures Installed Fair 1949 5,643
TRIB.MILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1925 5,642
MUD CREEK Indiana Scour Critical — Countermeasures Installed Fair 1985 5,641
SAW KILL New York Scour Critical — Countermeasures Installed Poor 1929 5,635
SEVILLE SUMNER DRAIN Michigan Scour Critical — Countermeasures Installed Poor 1936 5,634
N BRANCH BLACK RIVER Michigan Scour Critical — Countermeasures Installed Good 1992 5,632
CYPRESS CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1981 5,631
LITTLE WALNUT RIVER Kansas Scour Critical — Countermeasures Installed Fair 1970 5,627
BR.ASSISCUNK CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1925 5,626
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1950 5,624
BIG SANDY RIVER Tennessee Scour Critical — Countermeasures Installed Fair 1950 5,624
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1950 5,624
OVERFLOW Tennessee Scour Critical — Countermeasures Installed Fair 1950 5,624
WHITEWATER RIVER Indiana Scour Critical — Countermeasures Installed Fair 1935 5,622
IRON ORE CREEK Texas Scour Critical — Countermeasures Installed Fair 1955 5,622

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.