Conemaugh River at Johnstown

Highest listed crest 41.60 ftFlood stage 28.0 ft5 crests since 1889

The Conemaugh River at Johnstown crested at major flood stage 3 times among the 5 crests the National Weather Service lists from 1889 to 1996. The highest, 41.60 ft on May 31, 1889, was major flooding, 13.60 feet above flood stage.

The gauge

Highest listed crest: 41.60 ft; May 31, 1889
Flood stage: 28.0 ft; Major flooding from 34.0 ft
Crests at major: 3; 68th of 170 gauges in Pennsylvania
Most recent flood crest: July 20, 1977; 34.00 ft, major flooding
Location: Cambria County; Near Johnstown (1.1 mi)
Identifiers: NWS JHSP1; USGS 03041029

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, Conemaugh River at Johnstown

Action stage	23.0	1	Jan 19, 1996	The level at which the NWS or its partners begin to take action
Flood stage (minor)	28.0	0	—	Minimal or no property damage, but possibly some public threat
Moderate flood stage	30.0	1	Mar 29, 1924	Some inundation of structures and roads near the stream
Major flood stage	34.0	3	Jul 20, 1977	Extensive inundation of structures and roads

Every listed crest

5 crests from 1889 to 1996. Filled: at or above flood stage. Hover a crest for its date and stage.

Crests at or above flood stage, by decade

These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.

Highest crests

Highest listed crests, Conemaugh River at Johnstown

1	May 31, 1889	41.60	+13.60	Major	—
2	Mar 18, 1936	39.00	+11.00	Major	—
3	Jul 20, 1977	34.00	+6.00	Major	—
4	Mar 29, 1924	30.20	+2.20	Moderate	—
5	Jan 19, 1996	25.30	−2.70	Action	—

The worst floods along the Conemaugh River

For this gauge's highest crests, the other gauges on the Conemaugh River that crested above flood stage within a week.

March 18, 1936: 39.00 ft here, major flooding

SewardPA · Mar 18, 1936 · 26.40 ft · Major

July 20, 1977: 34.00 ft here, major flooding

SewardPA · Jul 20, 1977 · 27.06 ft · Major · its highest

Gauges on the Conemaugh River

In USGS station-number order, which runs downstream within a river basin.

Flood gauges on the Conemaugh River

Johnstown this gauge	PA	28.0	41.60 ft, May 31, 1889	3
Seward	PA	12.0	27.06 ft, Jul 20, 1977	4

Other gauges in Cambria County

Flood gauges in Cambria County

East Conemaugh	25.0	28.85 ft, Mar 17, 1936	1
Ferndale	19.0	23.21 ft, Jul 20, 1977	0

Cambria County: every hazard · River floods across the country · Pennsylvania

NOAA National Water Prediction Service, gauge JHSP1, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.