Allegheny River at Natrona Lock and Dam
Critical Stages
17.2' - Action
21' - Flood
24' - Moderate
26' - Major
Latest Observation
Updated: 11:15 PM EST 12/17/25
Status: No Flooding
Stage: 11 ft
Flow: 8.26 kcfs
Forecast
| Time | Stage (ft) | Flow (kcfs) |
|---|---|---|
| 1 AM 12/18 | 11.1 | 8.98 |
| 7 AM 12/18 | 11.1 | 8.98 |
| 1 PM 12/18 | 11.1 | 8.98 |
| 7 PM 12/18 | 11.1 | 8.98 |
| 1 AM 12/19 | 11.1 | 8.98 |
| 7 AM 12/19 | 11.1 | 8.98 |
| 1 PM 12/19 | 11.3 | 10.5 |
| 7 PM 12/19 | 11.4 | 11.2 |
| 1 AM 12/20 | 11.7 | 13.8 |
| 7 AM 12/20 | 11.9 | 15.6 |
| 1 PM 12/20 | 12.2 | 18.5 |
| 7 PM 12/20 | 12.4 | 20.5 |
| 1 AM 12/21 | 12.6 | 22.8 |
| 7 AM 12/21 | 12.8 | 24.9 |
| 1 PM 12/21 | 12.8 | 24.9 |
| 7 PM 12/21 | 12.7 | 23.8 |
| 1 AM 12/22 | 12.6 | 22.8 |
| 7 AM 12/22 | 12.5 | 21.6 |
| Time | Stage (ft) | Flow (kcfs) |
|---|---|---|
| 11:15 PM 12/17 | 11 | 8.26 |
| 11:00 PM 12/17 | 11 | 8.26 |
| 10:45 PM 12/17 | 10.98 | 8.1 |
| 10:30 PM 12/17 | 10.97 | 8.03 |
| 10:15 PM 12/17 | 10.96 | 7.95 |
| 10:00 PM 12/17 | 10.95 | 7.87 |
| 9:45 PM 12/17 | 10.94 | 7.8 |
| 9:30 PM 12/17 | 10.94 | 7.8 |
| 9:15 PM 12/17 | 10.94 | 7.8 |
| 9:00 PM 12/17 | 10.94 | 7.8 |
| 8:45 PM 12/17 | 10.94 | 7.8 |
| 8:30 PM 12/17 | 10.94 | 7.8 |
| 8:15 PM 12/17 | 10.95 | 7.87 |
| 8:00 PM 12/17 | 10.95 | 7.87 |
| 7:45 PM 12/17 | 10.96 | 7.95 |
| 7:30 PM 12/17 | 10.97 | 8.03 |
| 7:15 PM 12/17 | 10.98 | 8.1 |
| 7:00 PM 12/17 | 10.99 | 8.18 |
| 6:45 PM 12/17 | 11.01 | 8.33 |
| 6:30 PM 12/17 | 11.01 | 8.33 |
| 6:15 PM 12/17 | 11.03 | 8.47 |
| 6:00 PM 12/17 | 11.04 | 8.54 |
| 5:45 PM 12/17 | 11.05 | 8.61 |
| 5:30 PM 12/17 | 11.06 | 8.69 |
| 5:15 PM 12/17 | 11.07 | 8.76 |
| 5:00 PM 12/17 | 11.07 | 8.76 |
| 4:45 PM 12/17 | 11.07 | 8.76 |
| 4:30 PM 12/17 | 11.07 | 8.76 |
| 4:15 PM 12/17 | 11.07 | 8.76 |
| 4:00 PM 12/17 | 11.07 | 8.76 |
29.4' -
Pennsylvania Railroad main line and sidings affected at Tarentum PA, 3 miles downstream floods.
21.5' -
The Natrona Water Company is affected.
21.3' -
Water begins to back up into the sewers at Braeburn Steel Co.
21' -
Lock walls overtopped.
18' -
Navigation suspended, lock out of service.
| Date | Stage (ft) |
|---|---|
| Mar 18, 1936 | 32.1 |
| Dec 30, 1942 | 28.4 |
| Jan 22, 1959 | 27.6 |
| Jun 23, 1972 | 27.5 |
| Mar 10, 1964 | 26.4 |
| Sep 18, 2004 | 24.2 |
| Jan 20, 1996 | 23.1 |
| Feb 14, 1966 | 22.1 |
| Feb 17, 1976 | 21.8 |
| Mar 16, 2007 | 21.4 |
| Dec 31, 1990 | 20.7 |
| Jan 7, 2005 | 20 |
| Feb 9, 2019 | 18.63 |
| Feb 19, 2022 | 18.52 |
| Mar 24, 2007 | 17.84 |
Data provided by the National Weather Service.
