Reservoir · Colorado · United States · BOR RISE
Lake Granby
Lake Granby and Dam
48.1% full
Capacity
665.78 hm³
Volume stored
320 hm³
Vs month average
60% of normal
Coordinates
40.182°N, 105.871°W
Last updated
2026-10-27
Current fill
48.1%vs 7 days ago
-0.3 pplosing
vs 1 year ago
-33.7 ppyear-over-year
7-day trend
→stable
Drought context
Storage vs October average
60%of normal
48.1% full on 2026-10-27, against an average of 79.8% for October across 6 years of readings (-31.7 points).
Drought Monitor at this site · 20 October 2026
D3extreme drought
The ground at Lake Granby's coordinates falls inside the D3 area of the weekly U.S. Drought Monitor map. That describes local conditions — rainfall, soil moisture, streamflow — not the reservoir's storage. Colorado 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. 40.182°N, 105.871°W · Open in Google Maps
About Lake Granby
As of October 27, 2026, Lake Granby is filled to 48.1% of its total capacity, holding 320.27 hm³ of water out of a maximum 665.78 hm³. At this level the reservoir is within its normal operating range.
Over the most recent week on record the fill level has held broadly steady (-0.3 pp), and it is 33.7 points below its level on the same date a year earlier.
Across the readings we hold for Lake Granby — 1950 data points between October 29, 2021 and October 27, 2026 — the level has ranged from a low of 48.1% (October 27, 2026) to a high of 99.3% (July 8, 2023). 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 40.182°N, 105.871°W.
Key facts
- Current fill level
- 48.1% of total capacity
- Water stored
- 320.27 hm³
- Total capacity
- 665.78 hm³
- 7-day change
- ▼ 0.3 pp
- Year-on-year
- ▼ 33.7 pp
- Primary use
- Multipurpose
- Operator
- BOR
- Coordinates
- 40.182°N, 105.871°W
- Last updated
- October 27, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 27 Oct 2026 | 48.1% | 320.27 |
| 26 Oct 2026 | 48.2% | 320.64 |
| 25 Oct 2026 | 48.2% | 320.89 |
| 24 Oct 2026 | 48.3% | 321.39 |
| 23 Oct 2026 | 48.3% | 321.64 |
| 22 Oct 2026 | 48.3% | 321.89 |
| 21 Oct 2026 | 48.4% | 322.07 |
| 20 Oct 2026 | 48.4% | 322.39 |
| 19 Oct 2026 | 48.5% | 322.64 |
| 18 Oct 2026 | 48.5% | 323.01 |
| 17 Oct 2026 | 48.6% | 323.26 |
| 16 Oct 2026 | 48.6% | 323.77 |