Reservoir · North Dakota · United States · USACE CWMS
Garrison Dam & Reservoir
80.4% full
Capacity
22,819.42 hm³
Volume stored
18353 hm³
Coordinates
47.505°N, 101.432°W
Last updated
2026-07-29
Current fill
80.4%vs 7 days ago
-0.1%losing
vs 1 year ago
+1.2%year-over-year
7-day trend
→stable
Data source: USACE CWMS — US Army Corps of Engineers — 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: 2026-07-29.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 47.505, -101.432 · Open in Google Maps
About Garrison Dam & Reservoir
As of July 29, 2026, Garrison Dam & Reservoir is filled to 80.4% of its total capacity, holding roughly 18,353 hm³ of water out of a maximum 22,819 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-0.1 pts), and it is 1.2 points above its level on the same date a year earlier.
Across the readings we hold for Garrison Dam & Reservoir — 1821 data points between July 31, 2021 and July 29, 2026 — the level has ranged from a low of 76.2% (March 28, 2023) to a high of 105.0% (July 24, 2023). On average the reservoir is fullest around August and at its lowest around March.
It is operated by USACE primarily for multiple purposes. It lies within the North Dakota basin at 47.505°N, 101.432°W.
Key facts
- Current fill level
- 80.4%
- Water stored
- 18,353 hm³
- Total capacity
- 22,819 hm³
- 7-day change
- ▼ 0.1 pts
- Year-on-year
- ▲ 1.2 pts
- Primary use
- Multipurpose
- River basin
- North Dakota
- Operator
- USACE
- Coordinates
- 47.505°N, 101.432°W
- Last updated
- July 29, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 29 Jul 2026 | 80.4% | 18,353 |
| 28 Jul 2026 | 80.5% | 18,370 |
| 27 Jul 2026 | 80.6% | 18,388 |
| 26 Jul 2026 | 80.6% | 18,400 |
| 25 Jul 2026 | 80.7% | 18,420 |
| 24 Jul 2026 | 80.8% | 18,434 |
| 23 Jul 2026 | 80.9% | 18,453 |
| 22 Jul 2026 | 81.0% | 18,485 |
| 21 Jul 2026 | 81.1% | 18,502 |
| 20 Jul 2026 | 81.1% | 18,512 |
| 19 Jul 2026 | 81.2% | 18,528 |
| 18 Jul 2026 | 81.3% | 18,548 |
Frequently asked questions
What is the current water level of Garrison Dam & Reservoir?
As of July 29, 2026, Garrison Dam & Reservoir is at 80.4% of its capacity, holding approximately 18,353 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Garrison Dam & Reservoir reservoir full?
No. As of July 29, 2026, Garrison Dam & Reservoir is high at 80.4% of its capacity, so it is not full.
Is the water level at Garrison Dam & Reservoir rising or falling?
The level at Garrison Dam & Reservoir has been broadly stable over the latest week on record (-0.1 points).
How much water can Garrison Dam & Reservoir hold?
Garrison Dam & Reservoir has a total capacity of 22,819 hm³.
Where is Garrison Dam & Reservoir reservoir located?
Garrison Dam & Reservoir is located in North Dakota, United States, within the North Dakota basin (coordinates 47.505°N, 101.432°W).
What is Garrison Dam & Reservoir used for?
Garrison Dam & Reservoir is used primarily for multiple purposes, and is managed by USACE.