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
PLUM CREEK Michigan Scour Critical — Countermeasures Installed Fair 1955 31,883
MIDDLE BR CLINTON RIVER Michigan Scour Critical — Countermeasures Installed Good 1996 31,800
BRANCH BROWNS RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1960 31,662
WAILUA RIVER Hawaii Scour Critical — Countermeasures Installed Poor 1945 31,600
WAILUA RIVER Hawaii Scour Critical — Countermeasures Installed Fair 1920 31,600
BUFFALO CREEK Indiana Scour Critical — Countermeasures Installed Fair 1991 31,576
WATER CHARLES RIVER Massachusetts Scour Critical — Countermeasures Installed Fair 1888 31,500
Colorado River Arizona Scour Critical — Countermeasures Installed Fair 1987 31,500
BARNETT ROAD AT BEAR CR Oregon Scour Critical — Countermeasures Installed Fair 2009 31,423
PINE CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1925 31,339
BLACK CREEK Michigan Scour Critical — Countermeasures Installed Fair 1949 31,322
RUSH CREEK Michigan Scour Critical — Countermeasures Installed Fair 1933 31,311
SYCAMORE CREEK Michigan Scour Critical — Countermeasures Installed Fair 1956 31,200
WILLOW MEADOW BROOK New Jersey Scour Critical — Countermeasures Installed Fair 1959 31,084
WATER MARTINS BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1903 31,080
Indian Bend Wash Arizona Scour Critical — Countermeasures Installed Fair 1978 31,074
Rillito Creek Arizona Scour Critical — Countermeasures Installed Fair 1970 31,053
Mud Creek-Washington Arkansas Scour Critical — Countermeasures Installed Fair 1928 31,000
MANALAPAN BROOK New Jersey Scour Critical — Countermeasures Installed Poor 1927 30,910
WILLAMETTE RIVER Oregon Scour Critical — Countermeasures Installed Fair 1912 30,871
MIDDLE ROUGE RIVER Michigan Scour Critical — Countermeasures Installed Fair 1930 30,856
GRANDE DE ARECIBO RIVER Puerto Rico Scour Critical — Countermeasures Installed Good 1980 30,800
WHITE ROCK CREEK Texas Scour Critical — Countermeasures Installed Fair 1986 30,728
DES PLAINES RIVER Illinois Scour Critical — Countermeasures Installed Fair 1959 30,700
DES PLAINES RIVER Illinois Scour Critical — Countermeasures Installed Fair 1959 30,700
PASSAIC RIVER New Jersey Scour Critical — Countermeasures Installed Fair 1951 30,700
MIDDLE FK.FORKED DEER RI Tennessee Scour Critical — Countermeasures Installed Fair 1967 30,652
MIDDLE FK.FORKED DEER RI Tennessee Scour Critical — Countermeasures Installed Fair 1968 30,652
BUFFALO BAYOU Texas Scour Critical — Countermeasures Installed Fair 1968 30,601
HONEYMAN CREEK Oregon Scour Critical — Countermeasures Installed Fair 1919 30,567
WHITAKER BAYOU Florida Scour Critical — Countermeasures Installed Good 1923 30,500
PHILLIPPI CREEK Florida Scour Critical — Countermeasures Installed Good 1986 30,500
Biscayne Bay Florida Scour Critical — Countermeasures Installed Fair 1985 30,500
TROUT RIVER Florida Scour Critical — Countermeasures Installed Fair 1957 30,500
PLUM CREEK Michigan Scour Critical — Countermeasures Installed Fair 1988 30,475
PLUM CREEK Michigan Scour Critical — Countermeasures Installed Good 1964 30,475
CIBOLO CREEK & AZTEC WAY Texas Scour Critical — Countermeasures Installed Fair 2002 30,473
WOODEN BRIDGE RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1964 30,410
HUMACAO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1965 30,350
HUMACAO RIVER Puerto Rico Scour Critical — Countermeasures Installed Poor 1964 30,350
MISSISSIPPI RVR UP RR Missouri Scour Critical — Countermeasures Installed Fair 1990 30,251
MISSISSIPPI RVR UP RR Missouri Scour Critical — Countermeasures Installed Fair 1985 30,251
PLYMOUTH CREEK / 3368-E4 Pennsylvania Scour Critical — Countermeasures Installed Fair 1962 30,162
W. BR. NESHAMINY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1934 30,106
MILL CREEK Michigan Scour Critical — Countermeasures Installed Fair 1959 30,064
PENNYPACK CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1959 30,060
STEVENS CREEK California Scour Critical — Countermeasures Installed Fair 1933 30,000
MILL CREEK Illinois Scour Critical — Countermeasures Installed Fair 1953 29,900
FANCY BLUFF CREEK Georgia Scour Critical — Countermeasures Installed Good 1996 29,900
TOBY CREEK Pennsylvania Scour Critical — Countermeasures Installed Poor 1941 29,878

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.