Reservoir · South Dakota · United States · USACE CWMS
Castle Cr at Deerfield Dam, SD
92.1% full
Capacity
19.31 hm³
Volume stored
18 hm³
Coordinates
44.029°N, 103.786°W
Last updated
2026-07-29
Current fill
92.1%vs 7 days ago
0.0%stable
vs 1 year ago
-2.6%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. 44.029, -103.786 · Open in Google Maps
About Castle Cr at Deerfield Dam, SD
As of July 29, 2026, Castle Cr at Deerfield Dam, SD is filled to 92.1% of its total capacity, holding roughly 18 hm³ of water out of a maximum 19 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (+0.0 pts), and it is 2.6 points below its level on the same date a year earlier.
Across the readings we hold for Castle Cr at Deerfield Dam, SD — 1817 data points between July 31, 2021 and July 29, 2026 — the level has ranged from a low of 87.4% (July 11, 2025) to a high of 101.8% (July 2, 2023). On average the reservoir is fullest around June and at its lowest around October.
It is operated by USACE primarily for multiple purposes. It lies within the South Dakota basin at 44.029°N, 103.786°W.
Key facts
- Current fill level
- 92.1%
- Water stored
- 18 hm³
- Total capacity
- 19 hm³
- 7-day change
- No change
- Year-on-year
- ▼ 2.6 pts
- Primary use
- Multipurpose
- River basin
- South Dakota
- Operator
- USACE
- Coordinates
- 44.029°N, 103.786°W
- Last updated
- July 29, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 29 Jul 2026 | 92.1% | 18 |
| 28 Jul 2026 | 92.1% | 18 |
| 27 Jul 2026 | 92.2% | 18 |
| 26 Jul 2026 | 92.2% | 18 |
| 25 Jul 2026 | 92.2% | 18 |
| 24 Jul 2026 | 92.3% | 18 |
| 23 Jul 2026 | 92.1% | 18 |
| 22 Jul 2026 | 92.2% | 18 |
| 21 Jul 2026 | 92.3% | 18 |
| 20 Jul 2026 | 92.3% | 18 |
| 19 Jul 2026 | 92.4% | 18 |
| 18 Jul 2026 | 92.4% | 18 |
Frequently asked questions
What is the current water level of Castle Cr at Deerfield Dam, SD?
As of July 29, 2026, Castle Cr at Deerfield Dam, SD is at 92.1% of its capacity, holding approximately 18 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Castle Cr at Deerfield Dam, SD reservoir full?
No. As of July 29, 2026, Castle Cr at Deerfield Dam, SD is high at 92.1% of its capacity, so it is not full.
Is the water level at Castle Cr at Deerfield Dam, SD rising or falling?
The level at Castle Cr at Deerfield Dam, SD has been broadly stable over the latest week on record (0.0 points).
How much water can Castle Cr at Deerfield Dam, SD hold?
Castle Cr at Deerfield Dam, SD has a total capacity of 19 hm³.
Where is Castle Cr at Deerfield Dam, SD reservoir located?
Castle Cr at Deerfield Dam, SD is located in South Dakota, United States, within the South Dakota basin (coordinates 44.029°N, 103.786°W).
What is Castle Cr at Deerfield Dam, SD used for?
Castle Cr at Deerfield Dam, SD is used primarily for multiple purposes, and is managed by USACE.