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
SOUTH SULPHUR RIVER Texas Scour Critical — Countermeasures Ineffective Fair 1986 3,989
STREAM 2B6 Texas Scour Critical — Countermeasures Ineffective Fair 2009 3,985
W SISTER GROVE CREEK Texas Scour Critical — Countermeasures Ineffective Good 2008 3,962
E SISTER GROVE CREEK Texas Scour Critical — Countermeasures Ineffective Good 2008 3,962
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1976 3,940
BRUSHY CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Good 1980 3,934
BRUSHY CREEK SLOUGH Texas Scour Critical — Countermeasures Ineffective Fair 1980 3,934
BRUSHY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1980 3,934
SABINE RIVER Texas Scour Critical — Countermeasures Ineffective Good 2002 3,916
WATER MILL BROOK Massachusetts Scour Critical — Countermeasures Ineffective Good 2020 3,900
MESQUITE BRANCH Texas Scour Critical — Countermeasures Ineffective Good 2023 3,898
CCDD #1 MAIN DITCH Texas Scour Critical — Countermeasures Ineffective Good 2003 3,896
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1927 3,886
DRAINAGE DITCH # 1 Texas Scour Critical — Countermeasures Ineffective Fair 2013 3,884
Woody Branch Texas Scour Critical — Countermeasures Ineffective Good 1965 3,881
WATER LONG POND INLET Massachusetts Scour Critical — Countermeasures Ineffective Poor 1950 3,879
SAN BERNARD RIVER Texas Scour Critical — Countermeasures Ineffective Good 1988 3,876
DRAW Texas Scour Critical — Countermeasures Ineffective Good 2006 3,876
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 2006 3,876
Taylor Branch Texas Scour Critical — Countermeasures Ineffective Good 2024 3,875
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1966 3,859
WHITE OAK CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1964 3,859
WHITE OAK CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Good 1964 3,859
BEAR CREEK Texas Scour Critical — Countermeasures Ineffective Good 2013 3,850
GALVESTON BAY Texas Scour Critical — Countermeasures Ineffective Poor 1980 3,836
Drainage Ditch Texas Scour Critical — Countermeasures Ineffective Fair 1977 3,834
SQUIRREL CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1983 3,825
STANLEY CRK Texas Scour Critical — Countermeasures Ineffective Good 1983 3,825
HCFCD #0107-00-00 Texas Scour Critical — Countermeasures Ineffective Good 2002 3,822
DUCK CREEK Texas Scour Critical — Countermeasures Ineffective Good 1930 3,812
YOUNGS CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1936 3,781
WRIGHT CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1937 3,781
TOWN BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1971 3,754
Farmers Branch Texas Scour Critical — Countermeasures Ineffective Good 1977 3,731
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1960 3,730
WRENNS CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 3,725
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1926 3,723
MUD CREEK Texas Scour Critical — Countermeasures Ineffective Good 1957 3,715
Stone Dam Creek Arkansas Scour Critical — Countermeasures Ineffective Good 1991 3,700
TURKEY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1930 3,693
Big Creek Texas Scour Critical — Countermeasures Ineffective Good 1988 3,688
BEAR PEN CRK Texas Scour Critical — Countermeasures Ineffective Fair 1953 3,686
Ditch M Texas Scour Critical — Countermeasures Ineffective Good 1994 3,683
SCHLEY CREEK Georgia Scour Critical — Countermeasures Ineffective Good 2024 3,680
PAYNE CREEK Texas Scour Critical — Countermeasures Ineffective Good 2000 3,674
BRUSHY CREEK Texas Scour Critical — Countermeasures Ineffective Good 2000 3,674
CANEY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1954 3,673
TRIB TO HURRICANE CREEK Texas Scour Critical — Countermeasures Ineffective Good 2007 3,629
MAIN FLOODWAY Texas Scour Critical — Countermeasures Ineffective Fair 1963 3,615
BUFFALO BYU N BANK Texas Scour Critical — Countermeasures Ineffective Fair 1964 3,601

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.