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
SWAN CREEK	Michigan	Scour Critical — Unaddressed	Fair	1976	70
NPPID CANAL	Nebraska	Scour Critical — Unaddressed	Poor	1976	70
N BR BIG BLUE RIVER	Nebraska	Scour Critical — Unaddressed	Poor	1940	70
N BR W BR ESCANABA R	Michigan	Scour Critical — Unaddressed	Poor	1928	67
ALEXAUKEN CREEK	New Jersey	Scour Critical — Unaddressed	Poor	1900	67
QUACKEN KILL	New York	Scour Critical — Unaddressed	Poor	1930	67
TAYLOR BRANCH	Kentucky	Scour Critical — Unaddressed	Poor	1968	66
S BR YELLOW MEDICINE R	Minnesota	Scour Critical — Unaddressed	Fair	1967	65
FOURMILE CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1981	65
CLEAR CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	65
S CH PLATTE RIVER	Nebraska	Scour Critical — Unaddressed	Poor	1920	65
STONY CREEK	California	Scour Critical — Unaddressed	Poor	1960	63
LAKE FORK OVERFLOW CHAN.	Utah	Scour Critical — Unaddressed	Poor	1999	63
COLDFORK COTTONWOOD CRK	California	Scour Critical — Unaddressed	Poor	1921	60
SILVER CREEK	Idaho	Scour Critical — Unaddressed	Poor	1978	60
TURKEY CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1971	60
YANKEE CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	60
STREAM	Nebraska	Scour Critical — Unaddressed	Fair	1981	60
BATTLE CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	60
CLEARWATER RIVER	Minnesota	Scour Critical — Unaddressed	Fair	1935	59
MIDDLE PEARL CREEK	South Dakota	Scour Critical — Unaddressed	Poor	1928	56
SCOTT CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	55
PLUM CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1984	55
MESSENGER CREEK	Nebraska	Scour Critical — Unaddressed	Fair	1967	55
KENDUSKEAG STREAM	Maine	Scour Critical — Unaddressed	Poor	2001	54
MILL CREEK	Kentucky	Scour Critical — Unaddressed	Poor	1984	52
CARRABASSET STR	Maine	Scour Critical — Unaddressed	Poor	1936	52
TULLEY CREEK	Arkansas	Scour Critical — Unaddressed	Poor	1955	50
HOUSTON CREEK	California	Scour Critical — Unaddressed	Poor	1974	50
TOMPKINS CREEK	California	Scour Critical — Unaddressed	Poor	1988	50
SLATE CREEK	California	Scour Critical — Unaddressed	Poor	1956	50
MIDDLE MIAMI CREEK	California	Scour Critical — Unaddressed	Poor	1965	50
BLUE JOE CREEK	Idaho	Scour Critical — Unaddressed	Poor	1953	50
FRENCH CREEK	Idaho	Scour Critical — Unaddressed	Poor	1957	50
SELWAY RIVER-OHARA	Idaho	Scour Critical — Unaddressed	Poor	1956	50
EAST FORK FALL CREEK	Idaho	Scour Critical — Unaddressed	Poor	2013	50
SWAMP GUL	Montana	Scour Critical — Unaddressed	Poor	1987	50
CEDAR CR	Montana	Scour Critical — Unaddressed	Poor	1959	50
Welty Run	Pennsylvania	Scour Critical — Unaddressed	Poor	1972	50
Spruce Run	Pennsylvania	Scour Critical — Unaddressed	Poor	1901	50
STREAM	Nebraska	Scour Critical — Unaddressed	Fair	1985	50
LITTLE SWATARA CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	2007	50
STREAM	Nebraska	Scour Critical — Unaddressed	Fair	1967	50
DEER CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1972	50
KEFFER RUN	Pennsylvania	Scour Critical — Unaddressed	Poor	1981	50
STORM DRAINAGE	New Mexico	Scour Critical — Unaddressed	Fair	2015	50
MOSQUITO CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1960	50
JACKSON CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1994	50
SAND CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1950	50
OVER FOUR MILE RUN	Pennsylvania	Scour Critical — Unaddressed	Poor	1970	50

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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