Reservoir · Pennsylvania · United States · USACE CWMS
Loyalhanna Lake
18.5% full
Capacity
26.06 hm³
Volume stored
5 hm³
Coordinates
40.457°N, 79.451°W
Last updated
2026-09-11
Current fill
18.5%vs 7 days ago
-38.5%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. 40.457, -79.451 · Open in Google Maps
About Loyalhanna Lake
As of September 11, 2026, Loyalhanna Lake is filled to 18.5% of its total capacity, holding roughly 5 hm³ of water out of a maximum 26 hm³. At this level the reservoir is critically low.
Over the most recent week on record the fill level has fallen by 38.5 percentage points.
Across the readings we hold for Loyalhanna Lake — 324 data points between September 12, 2021 and September 11, 2026 — the level has ranged from a low of 7.6% (March 9, 2022) to a high of 100.0% (February 5, 2022). On average the reservoir is fullest around February and at its lowest around November.
It is operated by USACE primarily for multiple purposes. It lies within the Pennsylvania basin at 40.457°N, 79.451°W.
Key facts
- Current fill level
- 18.5%
- Water stored
- 5 hm³
- Total capacity
- 26 hm³
- 7-day change
- ▼ 38.5 pts
- Primary use
- Multipurpose
- River basin
- Pennsylvania
- Operator
- USACE
- Coordinates
- 40.457°N, 79.451°W
- Last updated
- September 11, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 11 Sep 2026 | 18.5% | 5 |
| 10 Sep 2026 | 18.7% | 5 |
| 9 Sep 2026 | 18.2% | 5 |
| 8 Sep 2026 | 23.5% | 6 |
| 7 Sep 2026 | 34.8% | 9 |
| 6 Sep 2026 | 49.7% | 13 |
| 5 Sep 2026 | 62.7% | 16 |
| 4 Sep 2026 | 57.0% | 15 |
| 3 Sep 2026 | 17.5% | 5 |
| 2 Sep 2026 | 16.5% | 4 |
| 1 Sep 2026 | 16.8% | 4 |
| 31 Aug 2026 | 17.6% | 5 |