Allegheny River at Freeport Lock and Dam

Highest listed crest 33.30 ftFlood stage 23.0 ft16 crests since 1936

The Allegheny River at Freeport Lock and Dam crested at major flood stage 1 time among the 16 crests the National Weather Service lists from 1936 to 2024. The highest, 33.30 ft on March 18, 1936, was major flooding, 10.30 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: 33.30 ft; March 18, 1936
Flood stage: 23.0 ft; Major flooding from 26.0 ft
Crests at major: 1; 103rd of 170 gauges in Pennsylvania
Most recent flood crest: March 16, 2007; 23.60 ft, minor flooding
Location: Armstrong County; Near Lower Burrell (7.5 mi), New Kensington (9.0 mi), Plum (13.3 mi)
Identifiers: NWS FREP1; USGS 03039040

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 Freeport Lock and Dam

Action stage	16.0	7	Apr 13, 2024	The level at which the NWS or its partners begin to take action
Flood stage (minor)	23.0	2	Mar 16, 2007	Minimal or no property damage, but possibly some public threat
Moderate flood stage	24.0	6	Sep 18, 2004	Some inundation of structures and roads near the stream
Major flood stage	26.0	1	Mar 18, 1936	Extensive inundation of structures and roads

Every listed crest

16 crests from 1936 to 2024. 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 Freeport Lock and Dam

1	Mar 18, 1936	33.30	+10.30	Major	—
2	Dec 30, 1942	25.70	+2.70	Moderate	—
3	Mar 10, 1964	25.30	+2.30	Moderate	—
4	Jan 20, 1996	25.00	+2.00	Moderate	—
5	Jan 22, 1959	24.80	+1.80	Moderate	—
6	Jun 23, 1972	24.50	+1.50	Moderate	—
7	Sep 18, 2004	24.10	+1.10	Moderate	145,500
8	Mar 16, 2007	23.60	+0.60	Minor	178,450
9	Mar 5, 1964	23.30	+0.30	Minor	—
10	Feb 14, 1966	22.70	−0.30	Action	—
11	Feb 19, 2022	22.58	−0.42	Action	—
12	Apr 13, 2024	22.52	−0.48	Action	—
13	Dec 31, 1990	22.50	−0.50	Action	—
14	Jun 21, 1989	22.20	−0.80	Action	—
15	Jan 29, 2024	19.54	−3.46	Action	—
16	Mar 23, 2007	18.50	−4.50	Action	89,340

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: 33.30 ft here, major flooding

Natrona Lock and DamPA · Mar 18, 1936 · 32.10 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: 25.70 ft here, moderate flooding

Natrona Lock and DamPA · Dec 30, 1942 · 28.40 ft · Major
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
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

March 10, 1964: 25.30 ft here, moderate flooding

Mosgrove Lock and DamPA · Mar 10, 1964 · 27.70 ft · Major · its highest
Natrona Lock and DamPA · Mar 10, 1964 · 26.40 ft · Major
Kittanning Lock and DamPA · Mar 10, 1964 · 24.80 ft · Major
C.W. Bill Young Lock and DamPA · Mar 10, 1964 · 21.40 ft · Moderate
WarrenPA · Mar 6, 1964 · 15.00 ft · Moderate
FranklinPA · Mar 10, 1964 · 18.60 ft · Minor
West HickoryPA · Mar 6, 1964 · 14.23 ft · Minor
SalamancaNY · Mar 6, 1964 · 12.87 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 this gauge	PA	23.0	33.30 ft, Mar 18, 1936	1
Natrona Lock and Dam	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 Armstrong County

Flood gauges in Armstrong County

Clinton Lock and Dam	21.0	26.40 ft, Mar 18, 1936	1
Kittanning Lock and Dam	21.0	30.70 ft, Mar 26, 1913	6
Mosgrove Lock and Dam	19.0	27.70 ft, Mar 10, 1964	2
Parker	20.0	29.60 ft, Jan 22, 1959	2
Rimer Lock and Dam	19.0	21.80 ft, Jan 22, 1959	0
Idaho	12.5	19.33 ft, Sep 18, 2004	0
St Charles	17.0	23.90 ft, Jul 19, 1996	1

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

NOAA National Water Prediction Service, gauge FREP1, 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.