Reservoir · North Dakota · United States · USACE CWMS
Heart Butte Dam & Reservoir
42.6% full
Capacity
135.47 hm³
Volume stored
58 hm³
Coordinates
46.598°N, 101.810°W
Last updated
2026-09-10
Current fill
42.6%vs 7 days ago
-0.2%losing
vs 1 year ago
-9.4%year-over-year
7-day trend
→stable
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Design capacity is unavailable for this site, so fill % is estimated against the 5-year maximum storage and may overstate fullness. Last reading: 2026-09-10.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 46.598, -101.810 · Open in Google Maps
About Heart Butte Dam & Reservoir
As of September 10, 2026, Heart Butte Dam & Reservoir is filled to 42.6% of its total capacity, holding roughly 58 hm³ of water out of a maximum 135 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 (-0.2 pts), and it is 9.4 points below its level on the same date a year earlier.
Across the readings we hold for Heart Butte Dam & Reservoir — 1821 data points between September 12, 2021 and September 10, 2026 — the level has ranged from a low of 39.2% (October 9, 2021) to a high of 100.0% (April 16, 2023). On average the reservoir is fullest around May and at its lowest around October.
It is operated by USACE primarily for multiple purposes. It lies within the North Dakota basin at 46.598°N, 101.810°W.
Key facts
- Current fill level
- 42.6%
- Water stored
- 58 hm³
- Total capacity
- 135 hm³
- 7-day change
- ▼ 0.2 pts
- Year-on-year
- ▼ 9.4 pts
- Primary use
- Multipurpose
- River basin
- North Dakota
- Operator
- USACE
- Coordinates
- 46.598°N, 101.810°W
- Last updated
- September 10, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 10 Sep 2026 | 42.6% | 58 |
| 9 Sep 2026 | 42.8% | 58 |
| 8 Sep 2026 | 42.9% | 58 |
| 7 Sep 2026 | 42.9% | 58 |
| 6 Sep 2026 | 42.9% | 58 |
| 5 Sep 2026 | 42.8% | 58 |
| 4 Sep 2026 | 42.9% | 58 |
| 3 Sep 2026 | 42.8% | 58 |
| 2 Sep 2026 | 42.9% | 58 |
| 1 Sep 2026 | 42.9% | 58 |
| 31 Aug 2026 | 42.9% | 58 |
| 30 Aug 2026 | 42.8% | 58 |