Reservoir · California · United States · CDEC
Lake Sonoma
100.7% full
Capacity
302.2 hm³
Volume stored
304 hm³
Coordinates
38.723°N, 123.010°W
Last updated
2026-08-03
Current fill
100.7%vs 7 days ago
-0.9%losing
vs 1 year ago
+0.9%year-over-year
7-day trend
→stable
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: 2026-08-03.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 38.723, -123.010 · Open in Google Maps
About Lake Sonoma
As of August 3, 2026, Lake Sonoma is filled to 100.7% of its total capacity, holding roughly 304 hm³ of water out of a maximum 302 hm³. At this level the reservoir is effectively full.
Over the most recent week on record the fill level has held broadly steady (-0.9 pts), and it sits close to where it was a year earlier.
Across the readings we hold for Lake Sonoma — 1822 data points between August 5, 2021 and August 3, 2026 — the level has ranged from a low of 39.3% (December 9, 2022) to a high of 105.0% (March 8, 2023). On average the reservoir is fullest around March and at its lowest around November.
It is operated by CDEC primarily for multiple purposes. It lies within the California basin at 38.723°N, 123.010°W.
Key facts
- Current fill level
- 100.7%
- Water stored
- 304 hm³
- Total capacity
- 302 hm³
- 7-day change
- ▼ 0.9 pts
- Year-on-year
- ▲ 0.9 pts
- Primary use
- Multipurpose
- River basin
- California
- Operator
- CDEC
- Coordinates
- 38.723°N, 123.010°W
- Last updated
- August 3, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 3 Aug 2026 | 100.7% | 304 |
| 2 Aug 2026 | 100.9% | 305 |
| 1 Aug 2026 | 101.0% | 305 |
| 31 Jul 2026 | 101.1% | 306 |
| 30 Jul 2026 | 101.2% | 306 |
| 29 Jul 2026 | 101.3% | 306 |
| 28 Jul 2026 | 101.5% | 307 |
| 27 Jul 2026 | 101.6% | 307 |
| 26 Jul 2026 | 101.7% | 307 |
| 25 Jul 2026 | 101.8% | 308 |
| 24 Jul 2026 | 102.0% | 308 |
| 23 Jul 2026 | 102.1% | 309 |
Frequently asked questions
What is the current water level of Lake Sonoma?
As of August 3, 2026, Lake Sonoma is at 100.7% of its capacity, holding approximately 304 hm³ of water, according to CDEC (CA DWR) data.
Is Lake Sonoma reservoir full?
Lake Sonoma is essentially full, sitting at 100.7% of capacity as of August 3, 2026.
Is the water level at Lake Sonoma rising or falling?
The level at Lake Sonoma has been broadly stable over the latest week on record (-0.9 points).
How much water can Lake Sonoma hold?
Lake Sonoma has a total capacity of 302 hm³.
Where is Lake Sonoma reservoir located?
Lake Sonoma is located in California, United States, within the California basin (coordinates 38.723°N, 123.010°W).
What is Lake Sonoma used for?
Lake Sonoma is used primarily for multiple purposes, and is managed by CDEC.