Reservoir · California · United States · CDEC
LAKE MC SWAIN
96.5% full
Capacity
10.18 hm³
Volume stored
10 hm³
Coordinates
37.520°N, 120.309°W
Last updated
2026-06-10
Current fill
96.5%vs 7 days ago
-3.5%losing
vs 1 year ago
-7.8%year-over-year
7-day trend
↓falling
Data source: CDEC — California Dept of Water Resources — 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: 2026-06-10.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 37.520, -120.309 · Open in Google Maps
About LAKE MC SWAIN
As of June 10, 2026, LAKE MC SWAIN is filled to 96.5% of its total capacity, holding roughly 10 hm³ of water out of a maximum 10 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has fallen by 3.5 percentage points, and it is 7.8 points below its level on the same date a year earlier.
Across the readings we hold for LAKE MC SWAIN — 1811 data points between June 13, 2021 and June 10, 2026 — the level has ranged from a low of 69.7% (December 1, 2025) to a high of 105.0% (June 13, 2021). On average the reservoir is fullest around September and at its lowest around November.
It is operated by CDEC primarily for multiple purposes. It lies within the California basin at 37.520°N, 120.309°W.
Key facts
- Current fill level
- 96.5%
- Water stored
- 10 hm³
- Total capacity
- 10 hm³
- 7-day change
- ▼ 3.5 pts
- Year-on-year
- ▼ 7.8 pts
- Primary use
- Multipurpose
- River basin
- California
- Operator
- CDEC
- Coordinates
- 37.520°N, 120.309°W
- Last updated
- June 10, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 10 Jun 2026 | 96.5% | 10 |
| 9 Jun 2026 | 100.0% | 10 |
| 8 Jun 2026 | 101.9% | 10 |
| 7 Jun 2026 | 98.6% | 10 |
| 6 Jun 2026 | 101.7% | 10 |
| 5 Jun 2026 | 97.7% | 10 |
| 4 Jun 2026 | 99.4% | 10 |
| 3 Jun 2026 | 98.9% | 10 |
| 2 Jun 2026 | 101.0% | 10 |
| 1 Jun 2026 | 100.4% | 10 |
| 31 May 2026 | 100.3% | 10 |
| 30 May 2026 | 98.5% | 10 |
Frequently asked questions
What is the current water level of LAKE MC SWAIN?
As of June 10, 2026, LAKE MC SWAIN is at 96.5% of its capacity, holding approximately 10 hm³ of water, according to CDEC (CA DWR) data.
Is LAKE MC SWAIN reservoir full?
LAKE MC SWAIN is essentially full, sitting at 96.5% of capacity as of June 10, 2026.
Is the water level at LAKE MC SWAIN rising or falling?
The level at LAKE MC SWAIN is falling — it dropped 3.5 percentage points over the latest week on record.
How much water can LAKE MC SWAIN hold?
LAKE MC SWAIN has a total capacity of 10 hm³.
Where is LAKE MC SWAIN reservoir located?
LAKE MC SWAIN is located in California, United States, within the California basin (coordinates 37.520°N, 120.309°W).
What is LAKE MC SWAIN used for?
LAKE MC SWAIN is used primarily for multiple purposes, and is managed by CDEC.