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
HOLLIDAY CREEK Texas Scour Critical — Countermeasures Ineffective Good 1995 4,525
SIX MILE CREEK RELIEF Texas Scour Critical — Countermeasures Ineffective Fair 1954 4,518
SIX MILE CREEK Texas Scour Critical — Countermeasures Ineffective Good 2007 4,518
SOUTH CREEK Texas Scour Critical — Countermeasures Ineffective Good 2004 4,510
ALLIGATOR CREEK Texas Scour Critical — Countermeasures Ineffective Good 2004 4,500
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Good 1960 4,490
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1928 4,468
BRANCH OF HOLLIDAY CREEK Texas Scour Critical — Countermeasures Ineffective Good 2016 4,468
GREENVIEW CREEK Texas Scour Critical — Countermeasures Ineffective Good 1942 4,461
BUS77 UPRR & PRIMERA RD Texas Scour Critical — Countermeasures Ineffective Fair 1967 4,457
CEDAR CREEK (CANEY CRK) Texas Scour Critical — Countermeasures Ineffective Good 2006 4,455
WOLF CREEK Texas Scour Critical — Countermeasures Ineffective Good 1957 4,454
HORSE CREEK Texas Scour Critical — Countermeasures Ineffective Good 1998 4,454
LITTLE WOLF CRK. Texas Scour Critical — Countermeasures Ineffective Good 1957 4,454
FORT EWELL CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1929 4,449
LITTLE LAKE CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1972 4,441
MILLER BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1954 4,427
Arroyo Dolores Texas Scour Critical — Countermeasures Ineffective Fair 1937 4,424
Arroyo Salado Texas Scour Critical — Countermeasures Ineffective Fair 1935 4,424
E FORK POST OAK CRK Texas Scour Critical — Countermeasures Ineffective Fair 1962 4,415
E FORK POST OAK CRK Texas Scour Critical — Countermeasures Ineffective Fair 1981 4,415
DEAN SWAMP South Carolina Scour Critical — Countermeasures Ineffective Good 2020 4,400
SALMON BRANCH OVERFLOW Texas Scour Critical — Countermeasures Ineffective Good 1925 4,396
SALMON BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1925 4,396
SALMON BRANCH OVERFLOW Texas Scour Critical — Countermeasures Ineffective Good 1925 4,396
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1929 4,392
HCWID #1 MASTER DRAIN Texas Scour Critical — Countermeasures Ineffective Good 1989 4,389
SHAWNEE CREEK Texas Scour Critical — Countermeasures Ineffective Good 2016 4,382
LAKE FORK Texas Scour Critical — Countermeasures Ineffective Good 1978 4,367
MENARD BRANCH Texas Scour Critical — Countermeasures Ineffective Good 1954 4,358
Pecan Creek Texas Scour Critical — Countermeasures Ineffective Good 1960 4,354
SCATTER CREEK Texas Scour Critical — Countermeasures Ineffective Good 2005 4,344
TEN MILE CRK/MAUK BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1964 4,338
L WICHITA SLOUGH Texas Scour Critical — Countermeasures Ineffective Fair 1929 4,328
ONION CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1929 4,328
N FLOODWAY PILOT CHANNEL Texas Scour Critical — Countermeasures Ineffective Fair 1941 4,321
Drainage Ditch Texas Scour Critical — Countermeasures Ineffective Good 1990 4,320
JACK CREEK TRIBUTARY Texas Scour Critical — Countermeasures Ineffective Good 1939 4,312
MCCOY CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1999 4,311
BRUTON CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1999 4,311
BASSETTS CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1931 4,311
Mason Creek Texas Scour Critical — Countermeasures Ineffective Good 1990 4,300
Mason Creek Texas Scour Critical — Countermeasures Ineffective Fair 1990 4,300
CHAUMONT RIVER New York Scour Critical — Countermeasures Ineffective Good 2024 4,296
MCGOWAN BROOK Rhode Island Scour Critical — Countermeasures Ineffective Good 2022 4,260
HCFCD DITCH Texas Scour Critical — Countermeasures Ineffective Fair 2001 4,250
PLUM CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1950 4,250
DRAW Texas Scour Critical — Countermeasures Ineffective Fair 1957 4,241
MUSTANG BRANCH Texas Scour Critical — Countermeasures Ineffective Fair 1964 4,236
TIMBER CREEK Texas Scour Critical — Countermeasures Ineffective Fair 1969 4,205

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.