Allegheny River at Natrona Lock and Dam

Highest listed crest 32.10 ftFlood stage 21.0 ft15 crests since 1936

The Allegheny River at Natrona Lock and Dam crested at major flood stage 5 times among the 15 crests the National Weather Service lists from 1936 to 2022. The highest, 32.10 ft on March 18, 1936, was major flooding, 11.10 feet above flood stage. 5 other gauges on the Allegheny River crested above flood stage within a week of it, 3 at their own highest listed crest.

The gauge

Highest listed crest: 32.10 ft; March 18, 1936; 365,000 cubic feet per second
Flood stage: 21.0 ft; Major flooding from 26.0 ft
Crests at major: 5; 44th of 170 gauges in Pennsylvania
Most recent flood crest: March 16, 2007; 21.40 ft, minor flooding
Location: Allegheny County; Near Lower Burrell (2.2 mi), New Kensington (3.5 mi), Plum (8.0 mi)
Identifiers: NWS NATP1; USGS 03049500

Flood stages

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

Flood categories, Allegheny River at Natrona Lock and Dam

Action stage	17.2	5	Feb 19, 2022	The level at which the NWS or its partners begin to take action
Flood stage (minor)	21.0	4	Mar 16, 2007	Minimal or no property damage, but possibly some public threat
Moderate flood stage	24.0	1	Sep 18, 2004	Some inundation of structures and roads near the stream
Major flood stage	26.0	5	Jun 23, 1972	Extensive inundation of structures and roads

Every listed crest

15 crests from 1936 to 2022. 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, Allegheny River at Natrona Lock and Dam

1	Mar 18, 1936	32.10	+11.10	Major	365,000
2	Dec 30, 1942	28.40	+7.40	Major	—
3	Jan 22, 1959	27.60	+6.60	Major	—
4	Jun 23, 1972	27.50	+6.50	Major	—
5	Mar 10, 1964	26.40	+5.40	Major	—
6	Sep 18, 2004	24.20	+3.20	Moderate	175,300
7	Jan 20, 1996	23.10	+2.10	Minor	—
8	Feb 14, 1966	22.10	+1.10	Minor	—
9	Feb 17, 1976	21.80	+0.80	Minor	—
10	Mar 16, 2007	21.40	+0.40	Minor	144,710
11	Dec 31, 1990	20.70	−0.30	Action	—
12	Jan 7, 2005	20.00	−1.00	Action	124,000
13	Feb 9, 2019	18.63	−2.37	Action	111,200
14	Feb 19, 2022	18.52	−2.48	Action	—
15	Mar 24, 2007	17.84	−3.16	Action	94,300

The worst floods along the Allegheny River

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

March 18, 1936: 32.10 ft here, major flooding

Freeport Lock and DamPA · Mar 18, 1936 · 33.30 ft · Major · its highest
C.W. Bill Young Lock and DamPA · Mar 18, 1936 · 31.10 ft · Major · its highest
Clinton Lock and DamPA · Mar 18, 1936 · 26.40 ft · Major · its highest
Kittanning Lock and DamPA · Mar 18, 1936 · 24.20 ft · Major
Mosgrove Lock and DamPA · Mar 18, 1936 · 19.60 ft · Minor

December 30, 1942: 28.40 ft here, major flooding

Kittanning Lock and DamPA · Dec 30, 1942 · 23.70 ft · Major
C.W. Bill Young Lock and DamPA · Dec 30, 1942 · 23.30 ft · Major
Freeport Lock and DamPA · Dec 30, 1942 · 25.70 ft · Moderate
Mosgrove Lock and DamPA · Dec 30, 1942 · 21.80 ft · Moderate
FranklinPA · Dec 30, 1942 · 18.30 ft · Minor
West HickoryPA · Dec 30, 1942 · 14.76 ft · Minor

January 22, 1959: 27.60 ft here, major flooding

ParkerPA · Jan 22, 1959 · 29.60 ft · Major · its highest
Kittanning Lock and DamPA · Jan 22, 1959 · 24.60 ft · Major
Freeport Lock and DamPA · Jan 22, 1959 · 24.80 ft · Moderate
Rimer Lock and DamPA · Jan 22, 1959 · 21.80 ft · Moderate · its highest
C.W. Bill Young Lock and DamPA · Jan 22, 1959 · 21.10 ft · Moderate
FranklinPA · Jan 21, 1959 · 20.60 ft · Moderate
OleanNY · Jan 22, 1959 · 18.00 ft · Moderate
WarrenPA · Jan 22, 1959 · 16.50 ft · Moderate
West HickoryPA · Jan 22, 1959 · 15.85 ft · Minor
SalamancaNY · Jan 22, 1959 · 12.99 ft · Minor

Gauges on the Allegheny River

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

Flood gauges on the Allegheny River

Eldred	PA	23.0	29.10 ft, Jun 23, 1972	2
Olean	NY	12.0	26.20 ft, Jun 23, 1972	2
Salamanca	NY	12.0	24.01 ft, Jun 23, 1972	1
Warren	PA	14.0	19.40 ft, Mar 17, 1865	6
West Hickory	PA	14.0	17.83 ft, Jan 25, 1964	3
Franklin	PA	17.0	26.00 ft, Feb 27, 1917	3
Parker	PA	20.0	29.60 ft, Jan 22, 1959	2
Rimer Lock and Dam	PA	19.0	21.80 ft, Jan 22, 1959	0
Mosgrove Lock and Dam	PA	19.0	27.70 ft, Mar 10, 1964	2
Kittanning Lock and Dam	PA	21.0	30.70 ft, Mar 26, 1913	6
Clinton Lock and Dam	PA	21.0	26.40 ft, Mar 18, 1936	1
Freeport Lock and Dam	PA	23.0	33.30 ft, Mar 18, 1936	1
Natrona Lock and Dam this gauge	PA	21.0	32.10 ft, Mar 18, 1936	5
C.W. Bill Young Lock and Dam	PA	17.0	31.10 ft, Mar 18, 1936	2
Sharpsburg Lock and Dam	PA	21.0	26.90 ft, Jun 24, 1972	1

Other gauges in Allegheny County

Flood gauges in Allegheny County

C.W. Bill Young Lock and Dam	17.0	31.10 ft, Mar 18, 1936	2
Sharpsburg Lock and Dam	21.0	26.90 ft, Jun 24, 1972	1
Carnegie	20.0	25.05 ft, Sep 18, 2004	1
Girty's Run	11.0	13.56 ft, Jul 5, 2018	0
Etna	9.0	10.28 ft, May 30, 1986	0
Braddock Lock and Dam	22.0	35.30 ft, Mar 18, 1936	8
Elizabeth Lock and Dam	20.0	32.50 ft, Mar 18, 1936	9
Dashields Lock and Dam	25.0	42.80 ft, Mar 18, 1936	5
Pittsburgh	22.0	46.00 ft, Mar 18, 1936	22
Etna	13.0	14.60 ft, Sep 1, 2021	0
Turtle Creek	6.0	11.34 ft, Jun 18, 2009	1
Sutersville	20.0	32.50 ft, Oct 16, 1954	12

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

NOAA National Water Prediction Service, gauge NATP1, 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.