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
OVER WARRIOR RUN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1925 4,456
E FK WHITE RIVER OVFL Indiana Scour Critical — Countermeasures Installed Fair 1981 4,454
YAHARA RIVER Wisconsin Scour Critical — Countermeasures Installed Fair 1934 4,450
W. BR. SCHUYLKILL RIVER Pennsylvania Scour Critical — Countermeasures Installed Fair 1957 4,450
ELK RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1967 4,450
MILL CREEK Illinois Scour Critical — Countermeasures Installed Poor 1932 4,450
ASOTIN CREEK Washington Scour Critical — Countermeasures Installed Good 1956 4,450
LITTLE WABASH RIVER Indiana Scour Critical — Countermeasures Installed Fair 1960 4,449
LITTLE RICHLAND CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1969 4,449
TULPEHOCKEN CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1926 4,439
OVER FISHING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1926 4,430
EAST FORK WHITE RIVER Indiana Scour Critical — Countermeasures Installed Good 1970 4,426
FALL CREEK Oregon Scour Critical — Countermeasures Installed Fair 1970 4,424
KLACKING CREEK Michigan Scour Critical — Countermeasures Installed Fair 1936 4,423
TITTABAWASSEE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1947 4,422
FISHEATING CREEK Florida Scour Critical — Countermeasures Installed Fair 1979 4,409
PLEASANT RIVER Maine Scour Critical — Countermeasures Installed Fair 1961 4,408
CHOCTAW CREEK Oklahoma Scour Critical — Countermeasures Installed Poor 1938 4,408
CANOVANAS RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1947 4,400
OLUSTEE CREEK Florida Scour Critical — Countermeasures Installed Fair 1968 4,400
DRY CREEK Idaho Scour Critical — Countermeasures Installed Fair 1964 4,400
McKAY CREEK Florida Scour Critical — Countermeasures Installed Good 1995 4,400
CURRY CREEK Florida Scour Critical — Countermeasures Installed Good 1991 4,400
FREEMAN GULCH California Scour Critical — Countermeasures Installed Good 1947 4,400
TRIB MUDDY CREEEK Texas Scour Critical — Countermeasures Installed Fair 2006 4,400
PITAHAYA RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1945 4,400
ALAMITOS CREEK California Scour Critical — Countermeasures Installed Good 1976 4,400
SANDY CREEK Mississippi Scour Critical — Countermeasures Installed Poor 1983 4,400
KNOWLTON BROOK Connecticut Scour Critical — Countermeasures Installed Fair 1929 4,400
CAIMITAL CREEK Puerto Rico Scour Critical — Countermeasures Installed Fair 1966 4,400
PITAHAYA RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1950 4,400
OSWEGO CANAL Oregon Scour Critical — Countermeasures Installed Fair 1934 4,400
WHITE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1970 4,400
ELK RIVER Minnesota Scour Critical — Countermeasures Installed Fair 1971 4,400
Sharps Run New Jersey Scour Critical — Countermeasures Installed Fair 1939 4,395
PINE RUN Michigan Scour Critical — Countermeasures Installed Fair 1937 4,394
COAL CREEK Kansas Scour Critical — Countermeasures Installed Good 1980 4,391
MIANUS RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1935 4,390
MILL RIVER Connecticut Scour Critical — Countermeasures Installed Fair 1946 4,386
RAYSTOWN BR.JUNIATA RIV. Pennsylvania Scour Critical — Countermeasures Installed Fair 1937 4,386
LITTLE CEDAR CREEK Texas Scour Critical — Countermeasures Installed Fair 1960 4,383
HATCHEL CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1950 4,380
SWAN CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1918 4,379
ROCK CREEK Kansas Scour Critical — Countermeasures Installed Good 1981 4,371
ELM CREEK Kansas Scour Critical — Countermeasures Installed Good 1980 4,371
JONES CREEK Alabama Scour Critical — Countermeasures Installed Fair 1927 4,370
CHEMUNG RIVER New York Scour Critical — Countermeasures Installed Good 1988 4,369
BAYOU CLEAR Louisiana Scour Critical — Countermeasures Installed Fair 1989 4,368
CANYON CREEK Oregon Scour Critical — Countermeasures Installed Fair 1921 4,363
SWIFTWATER CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1956 4,360

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.