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
TRIB. TO MILL CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	1939	150
NESHANNOCK WEST BRANCH	Pennsylvania	Scour Critical — Unaddressed	Poor	1940	150
ELKHORN RIVER	Nebraska	Scour Critical — Unaddressed	Fair	1986	150
PORTER CREEK	California	Scour Critical — Unaddressed	Poor	1968	140
Mill Creek	Kentucky	Scour Critical — Unaddressed	Poor	1990	140
TIBBY CREEK	Mississippi	Scour Critical — Unaddressed	Poor	1966	140
BIG SPRINGS CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1970	140
MALAD RIVER	Utah	Scour Critical — Unaddressed	Poor	1978	139
IRON CREEK	Michigan	Scour Critical — Unaddressed	Poor	1960	138
STONY RIVER	Minnesota	Scour Critical — Unaddressed	Poor	1972	137
DRAW	Texas	Scour Critical — Unaddressed	Fair	1960	137
DIFFICULT CREEK	Kentucky	Scour Critical — Unaddressed	Poor	1979	128
ELM CREEK	Minnesota	Scour Critical — Unaddressed	Poor	1965	128
WEST BAY STREAM	Maine	Scour Critical — Unaddressed	Poor	1980	126
THIRTY MILE CANAL	Nebraska	Scour Critical — Unaddressed	Poor	1927	125
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1935	125
BUTTE CREEK	California	Scour Critical — Unaddressed	Poor	1914	122
LITTLE BEICEGEL CREEK	North Dakota	Scour Critical — Unaddressed	Good	1988	120
BEAVER CREEK	Nebraska	Scour Critical — Unaddressed	Fair	1938	115
MIDDLE BOSQUE RIVER	Texas	Scour Critical — Unaddressed	Poor	1987	111
SMALL STREAM	Iowa	Scour Critical — Unaddressed	Poor	1956	110
CONASAUGA RIVER	Tennessee	Scour Critical — Unaddressed	Poor	1924	107
STREAM	Nebraska	Scour Critical — Unaddressed	Fair	1978	105
CO DITCH # 3	Minnesota	Scour Critical — Unaddressed	Poor	1974	105
REDBIRD RIVER	Kentucky	Scour Critical — Unaddressed	Poor	1935	104
SPRING CREEK	Texas	Scour Critical — Unaddressed	Poor	1997	103
DEEP CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	1920	100
CHESTUEE CREEK	Tennessee	Scour Critical — Unaddressed	Poor	1965	100
COLD RUN CREEK	Pennsylvania	Scour Critical — Unaddressed	Poor	1950	100
BIG CREEK TRESTLE	Idaho	Scour Critical — Unaddressed	Poor	1912	100
CLAYPOOL DR DITCH	Illinois	Scour Critical — Unaddressed	Poor	1916	100
CLEAR CR	Illinois	Scour Critical — Unaddressed	Fair	1978	100
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1928	100
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1920	100
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1962	100
GARLAND CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1972	100
SCOT RUN	Pennsylvania	Scour Critical — Unaddressed	Poor	1940	100
BIG LAKE CREEK 081	Montana	Scour Critical — Unaddressed	Poor	1958	100
BIG HOLE RIVER 123	Montana	Scour Critical — Unaddressed	Poor	1915	100
BOX ELDER CREEK 008	Montana	Scour Critical — Unaddressed	Poor	1930	100
RYE CREEK 064	Montana	Scour Critical — Unaddressed	Fair	1975	100
LITTLE BITTERROOT RV 092	Montana	Scour Critical — Unaddressed	Fair	2002	100
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1992	100
DIRTY CAMP RUN	Pennsylvania	Scour Critical — Unaddressed	Poor	1910	100
CUYAHOGA RIVER	Ohio	Scour Critical — Unaddressed	Poor	1900	100
Wissahickon Creek	Pennsylvania	Scour Critical — Unaddressed	Poor	1915	100
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1982	100
CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1970	100
IRRIGATION CANAL	Texas	Scour Critical — Unaddressed	Poor	1920	100
Big Sandy Creek	Texas	Scour Critical — Unaddressed	Poor	1996	100

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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