Reservoir · Pennsylvania · United States · USACE CWMS
Tionesta Lake
38.3% full
Capacity
57.4 hm³
Volume stored
22 hm³
Coordinates
41.474°N, 79.439°W
Last updated
2026-09-11
Current fill
38.3%vs 7 days ago
-8.1%losing
vs 1 year ago
N/A7-day trend
↓falling
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Design capacity is unavailable for this site, so fill % is estimated against the 5-year maximum storage and may overstate fullness. Last reading: 2026-09-11.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 41.474, -79.439 · Open in Google Maps
About Tionesta Lake
As of September 11, 2026, Tionesta Lake is filled to 38.3% of its total capacity, holding roughly 22 hm³ of water out of a maximum 57 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has fallen by 8.1 percentage points.
Across the readings we hold for Tionesta Lake — 327 data points between September 12, 2021 and September 11, 2026 — the level has ranged from a low of 15.8% (February 11, 2022) to a high of 100.0% (February 24, 2022). On average the reservoir is fullest around February and at its lowest around January.
It is operated by USACE primarily for multiple purposes. It lies within the Pennsylvania basin at 41.474°N, 79.439°W.
Key facts
- Current fill level
- 38.3%
- Water stored
- 22 hm³
- Total capacity
- 57 hm³
- 7-day change
- ▼ 8.1 pts
- Primary use
- Multipurpose
- River basin
- Pennsylvania
- Operator
- USACE
- Coordinates
- 41.474°N, 79.439°W
- Last updated
- September 11, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 11 Sep 2026 | 38.3% | 22 |
| 10 Sep 2026 | 39.1% | 22 |
| 9 Sep 2026 | 41.6% | 24 |
| 8 Sep 2026 | 45.4% | 26 |
| 7 Sep 2026 | 48.8% | 28 |
| 6 Sep 2026 | 51.1% | 29 |
| 5 Sep 2026 | 51.9% | 30 |
| 4 Sep 2026 | 46.4% | 27 |
| 3 Sep 2026 | 33.3% | 19 |
| 2 Sep 2026 | 21.0% | 12 |
| 1 Sep 2026 | 20.2% | 12 |
| 31 Aug 2026 | 20.4% | 12 |