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
PLUM CREEK Indiana Scour Critical — Countermeasures Installed Fair 1970 8,539
PLUM CREEK Indiana Scour Critical — Countermeasures Installed Fair 1970 8,539
W. BR. NESHAMINY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1927 8,535
LITTLE SWATARA CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1966 8,530
BRANCH MARTINS CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1957 8,523
HOUK DITCH Indiana Scour Critical — Countermeasures Installed Good 1988 8,521
FISHING CREEK Alabama Scour Critical — Countermeasures Installed Fair 1964 8,520
BRANCH STONY CR/ 3256-A8 Pennsylvania Scour Critical — Countermeasures Installed Fair 1973 8,516
CHAMBERS BROOK New Jersey Scour Critical — Countermeasures Installed Poor 1930 8,509
MIDDLEBURY RIVER Vermont Scour Critical — Countermeasures Installed Fair 1964 8,500
GUAJATACA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1978 8,500
ROCK RIV& MADISON ST Illinois Scour Critical — Countermeasures Installed Fair 1925 8,500
WILLOW SPRINGS WASH California Scour Critical — Countermeasures Installed Poor 1972 8,500
BRUJO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 2002 8,500
Miller Creek Florida Scour Critical — Countermeasures Installed Poor 1961 8,500
GRANDE CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1984 8,500
MORRO CREEK California Scour Critical — Countermeasures Installed Fair 1921 8,500
PASTILLO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1915 8,500
MASHAMOQUET BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1929 8,500
SANTA YNEZ RIVER California Scour Critical — Countermeasures Installed Fair 1939 8,500
DO¥A DOLORES CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1945 8,500
LOW BRANCH ROUGE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1935 8,500
PEARL RIVER Mississippi Scour Critical — Countermeasures Installed Fair 1967 8,500
UNNAMED CREEK Puerto Rico Scour Critical — Countermeasures Installed Poor 1994 8,500
CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1975 8,480
SANDY RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1931 8,478
TRIBUTARY MIDDLE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1941 8,477
SHELTON DITCH Oregon Scour Critical — Countermeasures Installed Fair 1954 8,475
BRANCH RIDLEY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1946 8,472
MURDER CREEK Alabama Scour Critical — Countermeasures Installed Fair 1953 8,472
JOHNSON BRANCH Indiana Scour Critical — Countermeasures Installed Good 1940 8,470
North Fork Wolf Creek Oregon Scour Critical — Countermeasures Installed Fair 1938 8,468
SOUCOOK RIVER New Hampshire Scour Critical — Countermeasures Installed Fair 1936 8,465
Flat Creek Oregon Scour Critical — Countermeasures Installed Fair 1933 8,459
LITTLE BUFFALO CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1929 8,458
PRAIRIE CREEK Michigan Scour Critical — Countermeasures Installed Poor 1929 8,456
Big Creek Oregon Scour Critical — Countermeasures Installed Fair 1951 8,456
RIFLE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1972 8,450
WOLF RIVER Tennessee Scour Critical — Countermeasures Installed Poor 1949 8,449
GREAT SOUTH BAY New York Scour Critical — Countermeasures Installed Good 1967 8,443
GREAT SOUTH BAY New York Scour Critical — Countermeasures Installed Fair 1951 8,443
POQUESSING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1970 8,438
GILBERT CREEK New York Scour Critical — Countermeasures Installed Fair 1928 8,430
W FORK LTL WILDCAT CR Indiana Scour Critical — Countermeasures Installed Fair 1986 8,417
ANNSVILLE CREEK New York Scour Critical — Countermeasures Installed Poor 1927 8,410
SCHUYLKILL RIVER Pennsylvania Scour Critical — Countermeasures Installed Poor 1935 8,408
Tomoka River Florida Scour Critical — Countermeasures Installed Fair 1968 8,400
TOWN BRANCH Arkansas Scour Critical — Countermeasures Installed Fair 1928 8,400
MYAKKAHATCHEE CREEK Florida Scour Critical — Countermeasures Installed Fair 1973 8,400
MILLS CREEK Michigan Scour Critical — Countermeasures Installed Good 2023 8,400

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.