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
DARBY CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1928 9,364
TIDBURY BRANCH Delaware Scour Critical — Countermeasures Installed Fair 1919 9,355
LOOSAHATCHIE RIVER Tennessee Scour Critical — Countermeasures Installed Poor 1970 9,352
OLIVER CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1926 9,349
SAND CREEK Indiana Scour Critical — Countermeasures Installed Good 1994 9,349
WHITE RIVER Indiana Scour Critical — Countermeasures Installed Poor 1973 9,340
N BR PENNSAUKEN CREEK New Jersey Scour Critical — Countermeasures Installed Fair 1941 9,324
PINEY CREEK Alabama Scour Critical — Countermeasures Installed Fair 1959 9,320
Upper Chloe Creek Kentucky Scour Critical — Countermeasures Installed Poor 1940 9,300
SUSQUEHANNA RIVER Pennsylvania Scour Critical — Countermeasures Installed Poor 1914 9,300
NEW CREEK California Scour Critical — Countermeasures Installed Fair 1924 9,300
CUSHING CREEK Florida Scour Critical — Countermeasures Installed Fair 1948 9,300
WADBOO SWAMP South Carolina Scour Critical — Countermeasures Installed Fair 1973 9,300
ST. JOSEPH SOUND (ICWW) Florida Scour Critical — Countermeasures Installed Fair 1963 9,300
CLINTON RIVER Michigan Scour Critical — Countermeasures Installed Good 1947 9,300
LIND COULEE Washington Scour Critical — Countermeasures Installed Fair 1954 9,298
EAST BRANCH DEEP CREEK Kansas Scour Critical — Countermeasures Installed Fair 1962 9,282
COYOTE CREEK California Scour Critical — Countermeasures Installed Fair 1930 9,275
WATER VINE BROOK Massachusetts Scour Critical — Countermeasures Installed Fair 1956 9,271
WHITE RIVER Indiana Scour Critical — Countermeasures Installed Good 1971 9,270
ABERNETHY CREEK Oregon Scour Critical — Countermeasures Installed Fair 1956 9,270
ABERNETHY CREEK Oregon Scour Critical — Countermeasures Installed Fair 1956 9,270
GRAYS CREEK Louisiana Scour Critical — Countermeasures Installed Fair 1956 9,267
CAYUGA CREEK New York Scour Critical — Countermeasures Installed Fair 1983 9,264
PASCACK BROOK New Jersey Scour Critical — Countermeasures Installed Poor 1900 9,261
POHOPOCO CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1934 9,256
SWAMP CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1947 9,235
MINE RUN Pennsylvania Scour Critical — Countermeasures Installed Fair 1928 9,235
CULVERT BRANCH Tennessee Scour Critical — Countermeasures Installed Good 1925 9,234
COOKS RUN Pennsylvania Scour Critical — Countermeasures Installed Poor 1926 9,221
DOUBLE BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1963 9,213
UMATILLA R/UPRR/USRS CAN Oregon Scour Critical — Countermeasures Installed Fair 1968 9,213
DOUBLE BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1963 9,213
SUMROW CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1963 9,213
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1965 9,213
SUMROW CREEK Tennessee Scour Critical — Countermeasures Installed Fair 1963 9,213
BRANCH Tennessee Scour Critical — Countermeasures Installed Fair 1958 9,213
RICKETTS BRANCH Texas Scour Critical — Countermeasures Installed Fair 1964 9,212
CARLANNA CREEK Alaska Scour Critical — Countermeasures Installed Fair 1973 9,210
TIOUGHNIOGA RIVER New York Scour Critical — Countermeasures Installed Fair 1947 9,205
LAURAMIE CREEK Indiana Scour Critical — Countermeasures Installed Fair 1925 9,205
SAMMAMISH R Washington Scour Critical — Countermeasures Installed Good 1963 9,203
Trib to Spruce Creek Florida Scour Critical — Countermeasures Installed Good 1961 9,200
SMACKS BAYOU Florida Scour Critical — Countermeasures Installed Poor 1965 9,200
COFFEE POT BAYOU Florida Scour Critical — Countermeasures Installed Fair 1928 9,200
UPCHURCHES POND North Carolina Scour Critical — Countermeasures Installed Fair 1984 9,200
PORTUGUES RIVER Puerto Rico Scour Critical — Countermeasures Installed Fair 1948 9,200
WYALUSING CREEK Pennsylvania Scour Critical — Countermeasures Installed Fair 1970 9,182
SHELDRAKE RIVER New York Scour Critical — Countermeasures Installed Fair 1935 9,181
BIG TIMBER CREEK New Jersey Scour Critical — Countermeasures Installed Poor 1934 9,175

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.