Reservoir · Montana · United States · BOR RISE
Lake Como
Lake Como and Como Dam
17.9% full
Capacity
47.48 hm³
Volume stored
9 hm³
Coordinates
46.062°N, 114.233°W
Last updated
2026-09-30
Current fill
17.9%vs 7 days ago
+0.4%gaining
vs 1 year ago
+6.9%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. 46.062, -114.233 · Open in Google Maps
About Lake Como
As of September 30, 2026, Lake Como is filled to 17.9% of its total capacity, holding roughly 9 hm³ of water out of a maximum 47 hm³. At this level the reservoir is critically low.
Over the most recent week on record the fill level has held broadly steady (+0.4 pts), and it is 6.9 points above its level on the same date a year earlier.
Across the readings we hold for Lake Como — 2186 data points between October 2, 2021 and September 30, 2026 — the level has ranged from a low of 9.2% (October 14, 2021) to a high of 102.3% (June 29, 2022). On average the reservoir is fullest around June and at its lowest around October.
It is operated by BOR primarily for multiple purposes. It lies within the Montana basin at 46.062°N, 114.233°W.
Key facts
- Current fill level
- 17.9%
- Water stored
- 9 hm³
- Total capacity
- 47 hm³
- 7-day change
- ▲ 0.4 pts
- Year-on-year
- ▲ 6.9 pts
- Primary use
- Multipurpose
- River basin
- Montana
- Operator
- BOR
- Coordinates
- 46.062°N, 114.233°W
- Last updated
- September 30, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 30 Sep 2026 | 17.9% | 9 |
| 29 Sep 2026 | 17.9% | 9 |
| 28 Sep 2026 | 17.8% | 8 |
| 27 Sep 2026 | 17.8% | 8 |
| 26 Sep 2026 | 17.7% | 8 |
| 25 Sep 2026 | 17.6% | 8 |
| 24 Sep 2026 | 17.6% | 8 |
| 23 Sep 2026 | 17.5% | 8 |
| 22 Sep 2026 | 17.4% | 8 |
| 21 Sep 2026 | 17.3% | 8 |
| 20 Sep 2026 | 17.1% | 8 |
| 19 Sep 2026 | 17.0% | 8 |