Reservoir · Washington · United States · USGS NWIS
Lake Tapps
86.5% full
Capacity
57.6 hm³
Volume stored
50 hm³
Coordinates
47.241°N, 122.192°W
Last updated
2026-09-30
Current fill
86.5%vs 7 days ago
-1.1%losing
vs 1 year ago
-5.3%year-over-year
7-day trend
→stable
Data source: USGS National Water Information System (NWIS) — 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: 2026-09-30.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 47.241, -122.192 · Open in Google Maps
About Lake Tapps
As of September 30, 2026, Lake Tapps is filled to 86.5% of its total capacity, holding roughly 50 hm³ of water out of a maximum 58 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-1.1 pts), and it is 5.3 points below its level on the same date a year earlier.
Across the readings we hold for Lake Tapps — 1459 data points between October 1, 2022 and September 30, 2026 — the level has ranged from a low of 73.6% (January 6, 2023) to a high of 99.9% (May 12, 2023). On average the reservoir is fullest around May and at its lowest around January.
It is operated by USGS primarily for multiple purposes. It lies within the Washington basin at 47.241°N, 122.192°W.
Key facts
- Current fill level
- 86.5%
- Water stored
- 50 hm³
- Total capacity
- 58 hm³
- 7-day change
- ▼ 1.1 pts
- Year-on-year
- ▼ 5.3 pts
- Primary use
- Multipurpose
- River basin
- Washington
- Operator
- USGS
- Coordinates
- 47.241°N, 122.192°W
- Last updated
- September 30, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 30 Sep 2026 | 86.5% | 50 |
| 29 Sep 2026 | 86.7% | 50 |
| 28 Sep 2026 | 86.9% | 50 |
| 27 Sep 2026 | 87.0% | 50 |
| 26 Sep 2026 | 87.2% | 50 |
| 25 Sep 2026 | 87.5% | 50 |
| 24 Sep 2026 | 87.4% | 50 |
| 23 Sep 2026 | 87.6% | 50 |
| 22 Sep 2026 | 87.9% | 51 |
| 21 Sep 2026 | 88.0% | 51 |
| 20 Sep 2026 | 88.2% | 51 |
| 19 Sep 2026 | 88.3% | 51 |