Reservoir · South Dakota · United States · USACE CWMS
Big Bend Dam & Reservoir
97.4% full
Capacity
2,127.76 hm³
Volume stored
2074 hm³
Coordinates
44.041°N, 99.445°W
Last updated
2026-07-29
Current fill
97.4%vs 7 days ago
-0.3%losing
vs 1 year ago
-0.5%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. 44.041, -99.445 · Open in Google Maps
About Big Bend Dam & Reservoir
As of July 29, 2026, Big Bend Dam & Reservoir is filled to 97.4% of its total capacity, holding roughly 2,074 hm³ of water out of a maximum 2,128 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-0.3 pts), and it sits close to where it was a year earlier.
Across the readings we hold for Big Bend Dam & Reservoir — 1821 data points between July 31, 2021 and July 29, 2026 — the level has ranged from a low of 94.9% (July 2, 2022) to a high of 99.2% (April 29, 2024). On average the reservoir is fullest around June and at its lowest around July.
It is operated by USACE primarily for multiple purposes. It lies within the South Dakota basin at 44.041°N, 99.445°W.
Key facts
- Current fill level
- 97.4%
- Water stored
- 2,074 hm³
- Total capacity
- 2,128 hm³
- 7-day change
- ▼ 0.3 pts
- Year-on-year
- ▼ 0.5 pts
- Primary use
- Multipurpose
- River basin
- South Dakota
- Operator
- USACE
- Coordinates
- 44.041°N, 99.445°W
- Last updated
- July 29, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 29 Jul 2026 | 97.4% | 2,073 |
| 28 Jul 2026 | 97.7% | 2,080 |
| 27 Jul 2026 | 98.3% | 2,091 |
| 26 Jul 2026 | 97.1% | 2,066 |
| 25 Jul 2026 | 96.1% | 2,044 |
| 24 Jul 2026 | 96.2% | 2,046 |
| 23 Jul 2026 | 96.2% | 2,046 |
| 22 Jul 2026 | 96.4% | 2,051 |
| 21 Jul 2026 | 96.9% | 2,062 |
| 20 Jul 2026 | 97.2% | 2,069 |
| 19 Jul 2026 | 96.2% | 2,046 |
| 18 Jul 2026 | 95.4% | 2,030 |
Frequently asked questions
What is the current water level of Big Bend Dam & Reservoir?
As of July 29, 2026, Big Bend Dam & Reservoir is at 97.4% of its capacity, holding approximately 2,074 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Big Bend Dam & Reservoir reservoir full?
Big Bend Dam & Reservoir is essentially full, sitting at 97.4% of capacity as of July 29, 2026.
Is the water level at Big Bend Dam & Reservoir rising or falling?
The level at Big Bend Dam & Reservoir has been broadly stable over the latest week on record (-0.3 points).
How much water can Big Bend Dam & Reservoir hold?
Big Bend Dam & Reservoir has a total capacity of 2,128 hm³.
Where is Big Bend Dam & Reservoir reservoir located?
Big Bend Dam & Reservoir is located in South Dakota, United States, within the South Dakota basin (coordinates 44.041°N, 99.445°W).
What is Big Bend Dam & Reservoir used for?
Big Bend Dam & Reservoir is used primarily for multiple purposes, and is managed by USACE.