Reservoir · Montana · United States · BOR RISE
Lake Elwell
Lake Elwell and Tiber Dam
84.3% full
Capacity
1,193.17 hm³
Volume stored
1006 hm³
Vs month average
107% of normal
Coordinates
48.318°N, 111.091°W
Last updated
2026-10-27
Current fill
84.3%vs 7 days ago
-0.4 pplosing
vs 1 year ago
+11.1 ppyear-over-year
7-day trend
→stable
Drought context
Storage vs October average
107%of normal
84.3% full on 2026-10-27, against an average of 78.8% for October across 6 years of readings (+5.5 points).
Drought Monitor at this site · 20 October 2026
Nonenot in a drought category
Lake Elwell's coordinates fall outside every category on the weekly U.S. Drought Monitor map. That describes local conditions — rainfall, soil moisture, streamflow — not the reservoir's storage. Montana drought figures →
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: 2026-10-27.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 48.318°N, 111.091°W · Open in Google Maps
About Lake Elwell
As of October 27, 2026, Lake Elwell is filled to 84.3% of its total capacity, holding 1,006 hm³ of water out of a maximum 1,193 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-0.4 pp), and it is 11.1 points above its level on the same date a year earlier.
Across the readings we hold for Lake Elwell — 1994 data points between October 29, 2021 and October 27, 2026 — the level has ranged from a low of 70.3% (February 20, 2025) to a high of 96.3% (July 5, 2026). On average the reservoir is fullest around July and at its lowest around March.
It is operated by BOR primarily for multiple purposes. It is at 48.318°N, 111.091°W.
Key facts
- Current fill level
- 84.3% of total capacity
- Water stored
- 1,006 hm³
- Total capacity
- 1,193 hm³
- 7-day change
- ▼ 0.4 pp
- Year-on-year
- ▲ 11.1 pp
- Primary use
- Multipurpose
- Operator
- BOR
- Coordinates
- 48.318°N, 111.091°W
- Last updated
- October 27, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 27 Oct 2026 | 84.3% | 1,006 |
| 26 Oct 2026 | 84.3% | 1,006 |
| 25 Oct 2026 | 84.4% | 1,007 |
| 24 Oct 2026 | 84.4% | 1,008 |
| 23 Oct 2026 | 84.5% | 1,009 |
| 22 Oct 2026 | 84.5% | 1,009 |
| 21 Oct 2026 | 84.6% | 1,009 |
| 20 Oct 2026 | 84.7% | 1,010 |
| 19 Oct 2026 | 84.7% | 1,011 |
| 18 Oct 2026 | 84.8% | 1,012 |
| 17 Oct 2026 | 84.9% | 1,013 |
| 16 Oct 2026 | 84.9% | 1,014 |