Reservoir · Washington · United States · BOR RISE
Billy Clapp Lake
Billy Clapp Lake and Pinto Dam
30.9% full
Capacity
79.19 hm³
Volume stored
25 hm³
Coordinates
47.448°N, 119.254°W
Last updated
2026-09-30
Current fill
30.9%vs 7 days ago
+0.2%gaining
vs 1 year ago
+2.1%year-over-year
7-day trend
→stable
Data source: BOR RISE — US Bureau of Reclamation — 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. 47.448, -119.254 · Open in Google Maps
About Billy Clapp Lake
As of September 30, 2026, Billy Clapp Lake is filled to 30.9% of its total capacity, holding roughly 25 hm³ of water out of a maximum 79 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has held broadly steady (+0.2 pts), and it is 2.1 points above its level on the same date a year earlier.
Across the readings we hold for Billy Clapp Lake — 2150 data points between October 2, 2021 and September 30, 2026 — the level has ranged from a low of 3.2% (December 10, 2025) to a high of 34.4% (August 9, 2025). On average the reservoir is fullest around July and at its lowest around February.
It is operated by BOR primarily for multiple purposes. It lies within the Washington basin at 47.448°N, 119.254°W.
Key facts
- Current fill level
- 30.9%
- Water stored
- 25 hm³
- Total capacity
- 79 hm³
- 7-day change
- ▲ 0.2 pts
- Year-on-year
- ▲ 2.1 pts
- Primary use
- Multipurpose
- River basin
- Washington
- Operator
- BOR
- Coordinates
- 47.448°N, 119.254°W
- Last updated
- September 30, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 30 Sep 2026 | 30.9% | 24 |
| 29 Sep 2026 | 30.9% | 24 |
| 28 Sep 2026 | 30.9% | 24 |
| 27 Sep 2026 | 30.7% | 24 |
| 26 Sep 2026 | 30.8% | 24 |
| 25 Sep 2026 | 30.7% | 24 |
| 24 Sep 2026 | 30.9% | 24 |
| 23 Sep 2026 | 30.7% | 24 |
| 22 Sep 2026 | 31.0% | 25 |
| 21 Sep 2026 | 31.4% | 25 |
| 20 Sep 2026 | 31.6% | 25 |
| 19 Sep 2026 | 31.5% | 25 |