Reservoir · Idaho · United States · BOR RISE
Mann Lake and Reservoir A Dam
32.9% full
Capacity
4.07 hm³
Volume stored
1 hm³
Coordinates
46.371°N, 116.858°W
Last updated
2026-08-12
Current fill
32.9%vs 7 days ago
-1.3%losing
vs 1 year ago
+4.9%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: 2026-08-12.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 46.371, -116.858 · Open in Google Maps
About Mann Lake and Reservoir A Dam
As of August 12, 2026, Mann Lake and Reservoir A Dam is filled to 32.9% of its total capacity, holding roughly 1 hm³ of water out of a maximum 4 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has held broadly steady (-1.3 pts), and it is 4.9 points above its level on the same date a year earlier.
Across the readings we hold for Mann Lake and Reservoir A Dam — 2188 data points between August 15, 2021 and August 12, 2026 — the level has ranged from a low of 23.6% (September 4, 2021) to a high of 73.7% (June 13, 2022). On average the reservoir is fullest around May and at its lowest around January.
It is operated by BOR primarily for multiple purposes. It lies within the Idaho basin at 46.371°N, 116.858°W.
Key facts
- Current fill level
- 32.9%
- Water stored
- 1 hm³
- Total capacity
- 4 hm³
- 7-day change
- ▼ 1.3 pts
- Year-on-year
- ▲ 4.9 pts
- Primary use
- Multipurpose
- River basin
- Idaho
- Operator
- BOR
- Coordinates
- 46.371°N, 116.858°W
- Last updated
- August 12, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 12 Aug 2026 | 32.9% | 1 |
| 11 Aug 2026 | 33.2% | 1 |
| 10 Aug 2026 | 33.2% | 1 |
| 9 Aug 2026 | 33.4% | 1 |
| 8 Aug 2026 | 33.7% | 1 |
| 7 Aug 2026 | 33.9% | 1 |
| 6 Aug 2026 | 33.9% | 1 |
| 5 Aug 2026 | 34.2% | 1 |
| 4 Aug 2026 | 34.6% | 1 |
| 3 Aug 2026 | 34.4% | 1 |
| 2 Aug 2026 | 35.1% | 1 |
| 1 Aug 2026 | 35.4% | 1 |
Frequently asked questions
What is the current water level of Mann Lake and Reservoir A Dam?
As of August 12, 2026, Mann Lake and Reservoir A Dam is at 32.9% of its capacity, holding approximately 1 hm³ of water, according to BOR RISE (US Bureau of Reclamation) data.
Is Mann Lake and Reservoir A Dam reservoir full?
No. As of August 12, 2026, Mann Lake and Reservoir A Dam is low at 32.9% of its capacity, so it is not full.
Is the water level at Mann Lake and Reservoir A Dam rising or falling?
The level at Mann Lake and Reservoir A Dam has been broadly stable over the latest week on record (-1.3 points).
How much water can Mann Lake and Reservoir A Dam hold?
Mann Lake and Reservoir A Dam has a total capacity of 4 hm³.
Where is Mann Lake and Reservoir A Dam reservoir located?
Mann Lake and Reservoir A Dam is located in Idaho, United States, within the Idaho basin (coordinates 46.371°N, 116.858°W).
What is Mann Lake and Reservoir A Dam used for?
Mann Lake and Reservoir A Dam is used primarily for multiple purposes, and is managed by BOR.