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
Drain Texas Scour Critical — Countermeasures Ineffective Fair 2020
LUBBUB CREEK Alabama Scour Critical — Countermeasures Ineffective Good 2024
STREAM - HAMILTON 50R36 Alaska Scour Critical — Countermeasures Ineffective Fair 1983
STONY CREEK New York Scour Critical — Countermeasures Ineffective Fair 2024
SANFORD LAKE New York Scour Critical — Countermeasures Ineffective Good 2024
OUTLET LAKE GEORGE New York Scour Critical — Countermeasures Ineffective Good 2024
Poesten Kill New York Scour Critical — Countermeasures Ineffective Good 2024
BROWNS CREEK New York Scour Critical — Countermeasures Ineffective Fair 2006
SHELDRAKE RIVER New York Scour Critical — Countermeasures Ineffective Good 2024
East Branch Sandy Creek New York Scour Critical — Countermeasures Ineffective Poor 1958
UNKNOWN STREAM New York Scour Critical — Countermeasures Ineffective Fair 1990
Mud Creek New York Scour Critical — Countermeasures Ineffective Fair 2024
Stephens Brook New York Scour Critical — Countermeasures Ineffective Fair 1931
PUTNAM CREEK New York Scour Critical — Countermeasures Ineffective Good 2024
Mud Creek New York Scour Critical — Countermeasures Ineffective Good 2024
Plattekill Creek New York Scour Critical — Countermeasures Ineffective Good 2024
ENGLISH BROOK 9 9 1710 New York Scour Critical — Countermeasures Ineffective Good 2024
SKAGIT RIVER Washington Scour Critical — Countermeasures Ineffective Fair 1940
SLOUGH California Scour Critical — Countermeasures Ineffective Poor 1945
BLACK RIVER New York Scour Critical — Countermeasures Ineffective Good 2024
WATER DRAINAGE Massachusetts Scour Critical — Countermeasures Ineffective Good 2004
WATER NORTHERN CANAL Massachusetts Scour Critical — Countermeasures Ineffective Poor 1848
TRENTON CHANNEL Michigan Scour Critical — Countermeasures Ineffective Fair 1913
SAN GABRIEL RIVER California Scour Critical — Countermeasures Installed Fair 1964 255,000
SPRING CREEK Texas Scour Critical — Countermeasures Installed Fair 1992 246,848
RIO HONDO California Scour Critical — Countermeasures Installed Fair 1966 224,000
SUISUN CREEK California Scour Critical — Countermeasures Installed Poor 1932 202,000
LOOKING GLASS RIVER Michigan Scour Critical — Countermeasures Installed Fair 1961 192,000
LOOKING GLASS RIVER Michigan Scour Critical — Countermeasures Installed Fair 1961 192,000
SAN PEDRO CREEK & RR Texas Scour Critical — Countermeasures Installed Fair 1986 173,066
HACKETT CREEK Oregon Scour Critical — Countermeasures Installed Fair 1965 165,900
ROUGE RIVER Michigan Scour Critical — Countermeasures Installed Good 1970 164,804
MRKT.MAIN.FRVW ST&SADRIV New Jersey Scour Critical — Countermeasures Installed Fair 1962 162,345
SR 14 BNRR Washington Scour Critical — Countermeasures Installed Fair 1982 160,000
TUALATIN RIVER Oregon Scour Critical — Countermeasures Installed Fair 1975 156,016
Columbia R./So. Channel Oregon Scour Critical — Countermeasures Installed Fair 1982 148,936
Columbia River Oregon Scour Critical — Countermeasures Installed Fair 1982 148,936
SPROUT BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1933 145,772
I-95 RMP 047/FIVE MI RIV Connecticut Scour Critical — Countermeasures Installed Fair 1956 136,600
ANACOSTIA RIVER District of Columbia Scour Critical — Countermeasures Installed Fair 1953 131,500
Trinity Ri University Dr Texas Scour Critical — Countermeasures Installed Fair 1951 131,220
Oregon Slough Oregon Scour Critical — Countermeasures Installed Fair 1987 125,775
WATTS BRANCH District of Columbia Scour Critical — Countermeasures Installed Fair 1956 122,000
SEEKONK RVR & STS Rhode Island Scour Critical — Countermeasures Installed Fair 1930 120,000
WATER MERRIMACK RIVER Massachusetts Scour Critical — Countermeasures Installed Poor 1959 119,818
MANOA PALOLO STRM Hawaii Scour Critical — Countermeasures Installed Fair 1967 112,200
MANOA PALOLO STRM(KING) Hawaii Scour Critical — Countermeasures Installed Fair 1948 112,200
BIG EAGLE CREEK Indiana Scour Critical — Countermeasures Installed Good 1967 109,416
BUFFALO BYU/ALLEN PKWY Texas Scour Critical — Countermeasures Installed Fair 1955 103,563
Willamette River Oregon Scour Critical — Countermeasures Installed Fair 1973 103,251

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.