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
ROUGE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1987 8,706
WENATCHEE RIVER Washington Scour Critical — Countermeasures Installed Fair 1962 8,705
WENATCHEE R Washington Scour Critical — Countermeasures Installed Fair 1962 8,705
WENATCHEE RIVER Washington Scour Critical — Countermeasures Installed Fair 1947 8,705
WENATCHEE RIVER Washington Scour Critical — Countermeasures Installed Poor 1929 8,705
HO-HO-KUS BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1900 8,704
WOLF CREEK Michigan Scour Critical — Countermeasures Installed Fair 1979 8,701
GRANDE DE LOIZA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1955 8,700
LA PLATA RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1951 8,700
Little Creek Arkansas Scour Critical — Countermeasures Installed Fair 1948 8,700
TRIB TO MOUNTAIN CRK South Carolina Scour Critical — Countermeasures Installed Good 1976 8,700
JACKSON BRANCH South Carolina Scour Critical — Countermeasures Installed Fair 1982 8,700
MOUNTAIN CREEK South Carolina Scour Critical — Countermeasures Installed Fair 1976 8,700
TRIB TO MOUNTAIN CK South Carolina Scour Critical — Countermeasures Installed Fair 1976 8,700
CULEBRA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1960 8,700
WHITEWATER RIVER California Scour Critical — Countermeasures Installed Poor 1950 8,700
NONEWAUG RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1928 8,700
TRIB TO MOUNTAIN CK South Carolina Scour Critical — Countermeasures Installed Good 1976 8,700
SECOND BROAD RIVER North Carolina Scour Critical — Countermeasures Installed Poor 1921 8,700
BAIROA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1981 8,700
LITTLE SUGAR CREEK Indiana Scour Critical — Countermeasures Installed Good 1964 8,700
CHENIERE CREEK Louisiana Scour Critical — Countermeasures Installed Poor 1970 8,694
EAST BR.RED CLAY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1940 8,686
PUKELE STRM Hawaii Scour Critical — Countermeasures Installed Fair 1928 8,680
LITTLE DUCK CREEK Indiana Scour Critical — Countermeasures Installed Fair 1986 8,673
TULPEHOCKEN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1949 8,670
TOOKANY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1927 8,669
WHETSTONE CREEK Oregon Scour Critical — Countermeasures Installed Good 1953 8,668
MILL CREEK Oregon Scour Critical — Countermeasures Installed Poor 1975 8,665
WATER MILLERS RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1850 8,663
HACKBERRY CREEK Texas Scour Critical — Countermeasures Installed Fair 1947 8,662
CHIPPEWA RIVER Michigan Scour Critical — Countermeasures Installed Poor 1961 8,658
CHIPPEWA RIVER Michigan Scour Critical — Countermeasures Installed Fair 1961 8,658
HOUGHS CREEK / 3039-B6 Pennsylvania Scour Critical — Countermeasures Installed Fair 1941 8,655
SWAMP CREEK Washington Scour Critical — Countermeasures Installed Poor 1960 8,654
MULBERRY CREEK Kansas Scour Critical — Countermeasures Installed Fair 1964 8,650
MULBERRY CREEK Kansas Scour Critical — Countermeasures Installed Fair 1964 8,650
NOROTON RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1950 8,650
OVERPECK CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1951 8,625
LONG BRANCH CREEK Texas Scour Critical — Countermeasures Installed Fair 1986 8,621
Shoal River Florida Scour Critical — Countermeasures Installed Fair 1930 8,600
INGENIO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1918 8,600
KELLY BROOK Wisconsin Scour Critical — Countermeasures Installed Fair 1932 8,600
GUANAJIBO RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1978 8,600
LITTLE BRANDYWINE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1921 8,593
BRANDYWINE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1942 8,593
ROCKAWAY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1900 8,583
DOUGLAS CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1955 8,579
KITTATINY BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1929 8,564
RIO HONDO New Mexico Scour Critical — Countermeasures Installed Fair 1972 8,558

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.