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
NEIGER HOLLOW CRK	New York	Scour Critical — Unaddressed	Poor	1940	261
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1993	260
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1995	255
THISTLE CREEK	Utah	Scour Critical — Unaddressed	Poor	2005	252
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1941	250
KNIGHTS RUN	Pennsylvania	Scour Critical — Unaddressed	Poor	1900	250
MEDICINE CREEK	Nebraska	Scour Critical — Unaddressed	Good	2024	250
SHEPARDS RIVER	Maine	Scour Critical — Unaddressed	Poor	1930	240
GOOSE RIVER	North Dakota	Scour Critical — Unaddressed	Good	1996	235
ELKHORN RIVER	Nebraska	Scour Critical — Unaddressed	Good	1982	235
WEBER-PROVO DIV. CANAL	Utah	Scour Critical — Unaddressed	Poor	1960	233
SYCAMORE CREEK	Kentucky	Scour Critical — Unaddressed	Poor	1948	233
BEAVER CREEK	Minnesota	Scour Critical — Unaddressed	Poor	1965	225
CANYON CREEK	Idaho	Scour Critical — Unaddressed	Poor	2012	220
MILL CREEK	California	Scour Critical — Unaddressed	Poor	1961	210
BIG CANYON CREEK	California	Scour Critical — Unaddressed	Poor	1956	208
RIVERDALE DITCH	California	Scour Critical — Unaddressed	Poor	1940	200
SO. PLATTE RIVER	Colorado	Scour Critical — Unaddressed	Poor	1923	200
OVER LITTLE SUGAR CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	1910	200
LAUREL RUN CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	1935	200
BRANCH OF SIXMILE CREEK	Indiana	Scour Critical — Unaddressed	Poor	1940	200
TUCANNON RIVER	Washington	Scour Critical — Unaddressed	Poor	1968	200
UNION FLAT CREEK	Washington	Scour Critical — Unaddressed	Fair	1910	200
Palo Duro Creek	Texas	Scour Critical — Unaddressed	Fair	1960	196
PRAIRIE CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1936	195
SOUTH OMAHA CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1938	195
SNAKE RIVER;SW BLISS BR	Idaho	Scour Critical — Unaddressed	Poor	1977	190
BEE CREEK	Texas	Scour Critical — Unaddressed	Fair	1990	189
FIRST CREEK	Kentucky	Scour Critical — Unaddressed	Poor	1935	188
SOUTH LOGAN CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	185
NORTH BR SALT RIVER	Michigan	Scour Critical — Unaddressed	Poor	1937	185
W FK BIG BLUE RIVER	Nebraska	Scour Critical — Unaddressed	Fair	1970	185
LAPWAI CREEK	Idaho	Scour Critical — Unaddressed	Poor	1935	180
PENOBSCOT RIVER OVERFLOW	Maine	Scour Critical — Unaddressed	Poor	1902	177
STREAM	Nebraska	Scour Critical — Unaddressed	Fair	1934	175
LITTLE MINERAL CREEK	Texas	Scour Critical — Unaddressed	Fair	2009	172
CRAPE CREEK	Mississippi	Scour Critical — Unaddressed	Poor	1972	170
COYOTE CREEK	New Mexico	Scour Critical — Unaddressed	Poor	1935	166
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1935	165
LITTLE TRAMMEL CREEK	Kentucky	Scour Critical — Unaddressed	Poor	1975	164
PENOBSCOT RIVER OVERFLOW	Maine	Scour Critical — Unaddressed	Poor	1902	158
SAND CREEK	South Dakota	Scour Critical — Unaddressed	Fair	1900	156
S BR HUMBUG CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1978	155
PINE CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	1952	154
LAGUNA CREEK	Arizona	Scour Critical — Unaddressed	Poor	1965	150
NESHANNOCK WEST BRANCH	Pennsylvania	Scour Critical — Unaddressed	Poor	1940	150
SOUTH REELFOOT CREEK	Tennessee	Scour Critical — Unaddressed	Poor	2008	150
HAWK CREEK	Minnesota	Scour Critical — Unaddressed	Poor	1959	150
TRIB. TO MILL CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	1939	150
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1984	150

Scour Critical Bridges by State

States ranked by number of scour critical bridges.

State	Scour Critical	Unaddressed	Countermeasures	Ineffective
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 — Unaddressed	Bridge is scour critical with no countermeasures installed. The foundation is vulnerable and no protective action has been taken.
Code 3 — Countermeasures Installed	Protective measures (riprap, sheet piling, etc.) have been installed to reduce scour risk, but the bridge remains classified as scour critical.
Code 6 — Countermeasures Ineffective	Protective 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.

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