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
Trib of Willow Creek Texas Scour Critical — Countermeasures Ineffective Good 2021 6,407
BEASLEY BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1999 6,390
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1977 6,381
BUFFALO BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1931 6,380
1ST ST & PREMONT DRAIN Texas Scour Critical — Countermeasures Ineffective Good 2022 6,368
CHACON CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1939 6,367
CentennialPkwyChannel W Nevada Scour Critical — Countermeasures Ineffective Good 2018 6,350
SPRING BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1971 6,319
Honey Spring Branch Texas Scour Critical — Countermeasures Ineffective Good 1975 6,319
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 2000 6,310
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 2000 6,310
MAIN FLOODWAY PILOT CH Texas Scour Critical — Countermeasures Ineffective Good 1996 6,309
HCFCD A-121-00-00 Texas Scour Critical — Countermeasures Ineffective Good 2006 6,294
EAST FORK CRYSTAL CREEK Texas Scour Critical — Countermeasures Ineffective Good 1989 6,286
COON CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1934 6,265
BIG BRUSHY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1934 6,265
BEE BAYOU Texas Scour Critical — Countermeasures Ineffective Fair 1934 6,265
GREENS BAYOU TRIB Texas Scour Critical — Countermeasures Ineffective Good 2011 6,263
GREENS BAYOU Texas Scour Critical — Countermeasures Ineffective Good 2013 6,263
DRAW Texas Scour Critical — Countermeasures Ineffective Good 1966 6,253
LAKE COLEMAN DRAIN Texas Scour Critical — Countermeasures Ineffective Fair 1974 6,244
Coon Creek Texas Scour Critical — Countermeasures Ineffective Good 1999 6,200
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1989 6,197
EAST MAIN DRAIN Texas Scour Critical — Countermeasures Ineffective Good 2007 6,159
EAST MAIN DRAIN Texas Scour Critical — Countermeasures Ineffective Good 2007 6,159
HICKORY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1969 6,143
TOWN CREEK Texas Scour Critical — Countermeasures Ineffective Good 1982 6,126
ARROYO COLORADO Texas Scour Critical — Countermeasures Ineffective Fair 1953 6,072
BIG SANDY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1934 6,060
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1999 6,055
DRY CREEK Georgia Scour Critical — Countermeasures Ineffective Good 2023 6,040
DRY CREEK Georgia Scour Critical — Countermeasures Ineffective Good 2023 6,040
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1966 6,035
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1982 6,035
BUFFALO HOLLOW Texas Scour Critical — Countermeasures Ineffective Good 1988 6,014
POST OAK CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1945 6,014
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1973 6,007
ELM CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1938 6,005
METZLER GULLY Texas Scour Critical — Countermeasures Ineffective Good 1991 6,000
TELGE RD WILLOW CREEK Texas Scour Critical — Countermeasures Ineffective Good 2015 6,000
COW BAYOU Texas Scour Critical — Countermeasures Ineffective Good 2008 6,000
COW BAYOU Texas Scour Critical — Countermeasures Ineffective Good 2008 6,000
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1975 6,000
PROTECTION LEVEE DITCH Texas Scour Critical — Countermeasures Ineffective Good 1993 5,998
DRAINAGE DITCH Texas Scour Critical — Countermeasures Ineffective Fair 1965 5,995
POST OAK CRK TRIB Texas Scour Critical — Countermeasures Ineffective Good 1962 5,968
GREENS BAYOU Texas Scour Critical — Countermeasures Ineffective Good 1981 5,961
WILSON CREEK TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Good 1982 5,943
LONG BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1938 5,927
DONNA DRAIN Texas Scour Critical — Countermeasures Ineffective Good 1967 5,914

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.