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
ROCK PARK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1932 13,466
TOWN CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1929 13,461
STONY RUN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1942 13,454
OVER FOURMILE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1930 13,435
MAMBICHE CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1957 13,400
MINILLAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1969 13,400
INFIERNO CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1925 13,400
WATER IPSWICH RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1850 13,394
HYDE RUN Delaware Scour Critical — Countermeasures Installed Fair 1936 13,392
Willamette River Oregon Scour Critical — Countermeasures Installed Fair 1971 13,386
W FRK E BR WHITE CLAY CR Pennsylvania Scour Critical — Countermeasures Installed Fair 1965 13,382
E.FRK. BR. WHITE CLAY CR Pennsylvania Scour Critical — Countermeasures Installed Fair 1965 13,382
DARBY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1931 13,380
Kilchis R. & Possetti Rd Oregon Scour Critical — Countermeasures Installed Poor 1952 13,357
MALHEUR RIVER Oregon Scour Critical — Countermeasures Installed Fair 1976 13,346
SCATTER CREEK Washington Scour Critical — Countermeasures Installed Fair 1926 13,337
WISSAHICKON CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1926 13,301
MALIKO STRM Hawaii Scour Critical — Countermeasures Installed Fair 1961 13,300
KENNEDY CREEK Washington Scour Critical — Countermeasures Installed Fair 1960 13,297
KENNEDY CREEK Washington Scour Critical — Countermeasures Installed Fair 1960 13,297
MILL RACE CANAL Oregon Scour Critical — Countermeasures Installed Good 1961 13,287
OVER SIX MILE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1954 13,267
SNAKE RIVER & BNRR Washington Scour Critical — Countermeasures Installed Fair 1950 13,260
WOODEN BRIDGE RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1953 13,244
PARK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1987 13,241
ELKCAM WATERWAY Florida Scour Critical — Countermeasures Installed Fair 1991 13,200
FISHERS FORK Indiana Scour Critical — Countermeasures Installed Fair 1978 13,199
WATER SANDERSDALE CANAL Massachusetts Scour Critical — Countermeasures Installed Fair 1900 13,189
HURON RIVER Michigan Scour Critical — Countermeasures Installed Fair 1978 13,169
WHIPPANY RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1947 13,160
POHATCONG CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1930 13,151
MUSCONETCONG RIVER New Jersey Scour Critical — Countermeasures Installed Good 1924 13,131
BRANCH MINE BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1921 13,131
MINE BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1921 13,131
YAKIMA RIVER Washington Scour Critical — Countermeasures Installed Fair 1932 13,121
BUSHKILL CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1886 13,117
PAWCATUCK RIVER Rhode Island Scour Critical — Countermeasures Installed Fair 1974 13,100
TURKEY CREEK South Carolina Scour Critical — Countermeasures Installed Fair 2005 13,100
LITTLE WHITE LICK CREEK Indiana Scour Critical — Countermeasures Installed Good 1958 13,094
Arizona Canal Arizona Scour Critical — Countermeasures Installed Fair 1946 13,080
POSSESSION SOUND Washington Scour Critical — Countermeasures Installed Good 2020 13,078
LAHAWAY CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1939 13,054
DARBY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1923 13,028
TRIB. TO SAUCON CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1922 13,025
BYBERRY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1963 13,022
BYBERRY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1963 13,022
WATER SPICKET RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1850 13,010
WATER PALMER RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1850 13,010
PEACE CREEK RELIEF Florida Scour Critical — Countermeasures Installed Good 1951 13,000
WATER SUDBURY RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1967 13,000

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.