Reservoir · Montana · United States · BOR RISE
Lake Elwell and Tiber Dam
91.8% full
Capacity
1,193.17 hm³
Volume stored
1096 hm³
Coordinates
48.318°N, 111.091°W
Last updated
2026-07-28
Current fill
91.8%vs 7 days ago
-0.2%losing
vs 1 year ago
-2.4%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: 2026-07-28.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 48.318, -111.091 · Open in Google Maps
About Lake Elwell and Tiber Dam
As of July 28, 2026, Lake Elwell and Tiber Dam is filled to 91.8% of its total capacity, holding roughly 1,096 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 (-0.2 pts), and it is 2.4 points below its level on the same date a year earlier.
Across the readings we hold for Lake Elwell and Tiber Dam — 1867 data points between July 31, 2021 and July 28, 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 lies within the Montana basin at 48.318°N, 111.091°W.
Key facts
- Current fill level
- 91.8%
- Water stored
- 1,096 hm³
- Total capacity
- 1,193 hm³
- 7-day change
- ▼ 0.2 pts
- Year-on-year
- ▼ 2.4 pts
- Primary use
- Multipurpose
- River basin
- Montana
- Operator
- BOR
- Coordinates
- 48.318°N, 111.091°W
- Last updated
- July 28, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 28 Jul 2026 | 91.8% | 1,096 |
| 27 Jul 2026 | 92.0% | 1,097 |
| 26 Jul 2026 | 92.3% | 1,101 |
| 25 Jul 2026 | 92.7% | 1,106 |
| 24 Jul 2026 | 93.0% | 1,110 |
| 23 Jul 2026 | 93.3% | 1,113 |
| 22 Jul 2026 | 93.6% | 1,116 |
| 21 Jul 2026 | 93.7% | 1,118 |
| 20 Jul 2026 | 93.9% | 1,121 |
| 19 Jul 2026 | 94.1% | 1,123 |
| 18 Jul 2026 | 94.3% | 1,125 |
| 17 Jul 2026 | 94.5% | 1,127 |
Frequently asked questions
What is the current water level of Lake Elwell and Tiber Dam?
As of July 28, 2026, Lake Elwell and Tiber Dam is at 91.8% of its capacity, holding approximately 1,096 hm³ of water, according to BOR RISE (US Bureau of Reclamation) data.
Is Lake Elwell and Tiber Dam reservoir full?
No. As of July 28, 2026, Lake Elwell and Tiber Dam is high at 91.8% of its capacity, so it is not full.
Is the water level at Lake Elwell and Tiber Dam rising or falling?
The level at Lake Elwell and Tiber Dam has been broadly stable over the latest week on record (-0.2 points).
How much water can Lake Elwell and Tiber Dam hold?
Lake Elwell and Tiber Dam has a total capacity of 1,193 hm³.
Where is Lake Elwell and Tiber Dam reservoir located?
Lake Elwell and Tiber Dam is located in Montana, United States, within the Montana basin (coordinates 48.318°N, 111.091°W).
What is Lake Elwell and Tiber Dam used for?
Lake Elwell and Tiber Dam is used primarily for multiple purposes, and is managed by BOR.