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
DEER CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1972	50
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1930	50
LITTLE ROCK CREEK	Wyoming	Scour Critical — Unaddressed	Poor	1976	50
BETTY LOGAN CREEK	Texas	Scour Critical — Unaddressed	Poor	1931	50
N BR COWANESQUE RIVER	Pennsylvania	Scour Critical — Unaddressed	Poor	1951	50
SILVER CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1971	50
JIVERS CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	50
KEFFER RUN	Pennsylvania	Scour Critical — Unaddressed	Poor	1981	50
SUNSET CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1939	50
Welty Run	Pennsylvania	Scour Critical — Unaddressed	Poor	1972	50
Spruce Run	Pennsylvania	Scour Critical — Unaddressed	Poor	1901	50
DRY CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	50
LOUP RIVER CANAL	Nebraska	Scour Critical — Unaddressed	Poor	1935	50
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1935	50
LOUP RIVER CANAL	Nebraska	Scour Critical — Unaddressed	Poor	1935	50
N BR BIG BLUE RIVER	Nebraska	Scour Critical — Unaddressed	Poor	1950	50
N BR BIG BLUE RIVER	Nebraska	Scour Critical — Unaddressed	Poor	1950	50
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1983	50
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1935	50
OAK CREEK	Nebraska	Scour Critical — Unaddressed	Good	2024	50
MOSQUITO CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1960	50
TUB RUN CREEK	Pennsylvania	Scour Critical — Unaddressed	Fair	1989	50
SAND CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1950	50
ROCKY BRANCH	Texas	Scour Critical — Unaddressed	Poor	2013	50
ASH CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	50
W. BR. WALLENPAUPACK CR.	Pennsylvania	Scour Critical — Unaddressed	Poor	1930	50
WILLOW CREEK	Oklahoma	Scour Critical — Unaddressed	Poor	1983	50
STORM DRAINAGE	New Mexico	Scour Critical — Unaddressed	Good	2016	50
STORM DRAINAGE	New Mexico	Scour Critical — Unaddressed	Fair	2015	50
LOWER KANAWHA RUN	West Virginia	Scour Critical — Unaddressed	Fair	2020	48
SHELL RIVER	Minnesota	Scour Critical — Unaddressed	Fair	1984	45
CALLAHAN CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	45
NIOBRARA RIVER	Nebraska	Scour Critical — Unaddressed	Fair	1935	45
WALLACE CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1977	45
CREEK	North Dakota	Scour Critical — Unaddressed	Poor	2002	45
STREAM	Nebraska	Scour Critical — Unaddressed	Fair	1935	45
MISSION CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	45
ADAMSON CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	45
STREAM	Nebraska	Scour Critical — Unaddressed	Poor	1913	45
SILVER BRANCH	Nebraska	Scour Critical — Unaddressed	Poor	1950	45
OVER SMOKEY CREEK	Kentucky	Scour Critical — Unaddressed	Poor	1997	44
ROCKY CREEK	Texas	Scour Critical — Unaddressed	Poor	1988	41
MULKEY CR	Missouri	Scour Critical — Unaddressed	Poor	1900	40
Sun River	Montana	Scour Critical — Unaddressed	Poor	1916	40
ANTELOPE CREEK	Nebraska	Scour Critical — Unaddressed	Fair	1955	40
ROCK CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1930	40
DRY CREEK	Nebraska	Scour Critical — Unaddressed	Poor	1935	40
N FK ELKHORN RIVER	Nebraska	Scour Critical — Unaddressed	Poor	1935	40
SHELL CREEK TRIBUTARY	Nebraska	Scour Critical — Unaddressed	Fair	1976	40
LITTLE BLUE RIVER	Nebraska	Scour Critical — Unaddressed	Poor	1935	40

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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