Reservoir · Ohio · United States · USACE CWMS
Tappan Lake
100.9% full
Capacity
43.3 hm³
Volume stored
44 hm³
Coordinates
40.356°N, 81.226°W
Last updated
2026-09-11
Current fill
100.9%vs 7 days ago
-0.1%losing
vs 1 year ago
N/A7-day trend
→stable
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Capacity is the design (normal full-pool) capacity from the US National Inventory of Dams (NID); fill % = current volume ÷ design capacity. 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. 40.356, -81.226 · Open in Google Maps
About Tappan Lake
As of September 11, 2026, Tappan Lake is filled to 100.9% of its total capacity, holding roughly 44 hm³ of water out of a maximum 43 hm³. At this level the reservoir is effectively full.
Over the most recent week on record the fill level has held broadly steady (-0.1 pts).
Across the readings we hold for Tappan Lake — 100 data points between September 12, 2021 and September 11, 2026 — the level has ranged from a low of 98.6% (August 1, 2026) to a high of 104.8% (August 17, 2026).
It is operated by USACE primarily for multiple purposes. It lies within the Ohio basin at 40.356°N, 81.226°W.
Key facts
- Current fill level
- 100.9%
- Water stored
- 44 hm³
- Total capacity
- 43 hm³
- 7-day change
- ▼ 0.1 pts
- Primary use
- Multipurpose
- River basin
- Ohio
- Operator
- USACE
- Coordinates
- 40.356°N, 81.226°W
- Last updated
- September 11, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 11 Sep 2026 | 100.9% | 44 |
| 10 Sep 2026 | 100.9% | 44 |
| 9 Sep 2026 | 100.4% | 43 |
| 8 Sep 2026 | 100.5% | 44 |
| 7 Sep 2026 | 100.7% | 44 |
| 6 Sep 2026 | 100.9% | 44 |
| 5 Sep 2026 | 101.0% | 44 |
| 4 Sep 2026 | 101.0% | 44 |
| 3 Sep 2026 | 101.3% | 44 |
| 2 Sep 2026 | 101.5% | 44 |
| 1 Sep 2026 | 101.6% | 44 |
| 31 Aug 2026 | 101.9% | 44 |