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
FRENCH CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1948 13,173
DRAIN Texas Scour Critical — Countermeasures Ineffective Good 1990 13,156
DRAIN Texas Scour Critical — Countermeasures Ineffective Fair 1990 13,156
CHOATES CREEK Texas Scour Critical — Countermeasures Ineffective Good 2023 13,125
WATTERS CREEK Texas Scour Critical — Countermeasures Ineffective Good 1997 13,005
WATTERS CREEK Texas Scour Critical — Countermeasures Ineffective Fair 2007 13,005
WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Good 1990 13,000
WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Good 1990 13,000
CARY BAYOU Texas Scour Critical — Countermeasures Ineffective Good 1970 12,982
DUGAN CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1959 12,979
HIGHLAND BAYOU D.C. Texas Scour Critical — Countermeasures Ineffective Good 1977 12,920
CORBIN BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1954 12,917
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1929 12,907
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1976 12,907
HCFCD DITCH L Texas Scour Critical — Countermeasures Ineffective Good 1992 12,863
HCFCD DITCH L Texas Scour Critical — Countermeasures Ineffective Good 1992 12,863
WEST CANAL Texas Scour Critical — Countermeasures Ineffective Fair 1970 12,850
Brooks Branch Texas Scour Critical — Countermeasures Ineffective Fair 1977 12,841
DRY CREEK Texas Scour Critical — Countermeasures Ineffective Good 1971 12,831
LITTLE WHITE OAK BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1999 12,820
IH 635/US 80 Texas Scour Critical — Countermeasures Ineffective Poor 1971 12,819
CRYSTAL CREEK TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Good 2010 12,795
MAIN FLDWY PILOT CHANNEL Texas Scour Critical — Countermeasures Ineffective Fair 1968 12,714
MAIN FLDWY PILOT CHANNEL Texas Scour Critical — Countermeasures Ineffective Fair 1957 12,714
Bighead Cr Texas Scour Critical — Countermeasures Ineffective Fair 1923 12,702
RABBS BAYOU Texas Scour Critical — Countermeasures Ineffective Good 2015 12,689
Willamette River Oregon Scour Critical — Countermeasures Ineffective Fair 2023 12,687
TURTLE CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1969 12,651
PECAN CREEK Texas Scour Critical — Countermeasures Ineffective Good 2010 12,621
SAN MARTIN LAKE Texas Scour Critical — Countermeasures Ineffective Good 2007 12,608
BAHIA GRANDE Texas Scour Critical — Countermeasures Ineffective Good 2007 12,608
TRIB TO LAKE WORTH Texas Scour Critical — Countermeasures Ineffective Fair 1940 12,603
Snake Creek Texas Scour Critical — Countermeasures Ineffective Good 2009 12,602
W FORK SPRING BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1943 12,598
Cagle Branch Crk Texas Scour Critical — Countermeasures Ineffective Good 2024 12,598
LYNCHBURG RESERVOIR CAN Texas Scour Critical — Countermeasures Ineffective Good 1973 12,593
HCFCD DITCH (U102-28-00) Texas Scour Critical — Countermeasures Ineffective Good 2009 12,546
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1984 12,517
IH10WBFR BW8SBFR BRK VW Texas Scour Critical — Countermeasures Ineffective Good 1994 12,500
S MAIN DRAINAGE D Texas Scour Critical — Countermeasures Ineffective Good 1988 12,440
CANE BR BUFFALO BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1967 12,437
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1974 12,410
I-294/I-90/Willow Creek Illinois Scour Critical — Countermeasures Ineffective Fair 1958 12,400
Five Mile Creek Texas Scour Critical — Countermeasures Ineffective Fair 1948 12,383
BUFFALO HOLLOW Texas Scour Critical — Countermeasures Ineffective Fair 1941 12,376
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 2013 12,312
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1992 12,310
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1998 12,310
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1992 12,310
PEACH CR & MARE BR Texas Scour Critical — Countermeasures Ineffective Good 2007 12,244

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.