Reservoir · California · United States · CDEC
DIAMOND VALLEY
98.7% full
Capacity
986.79 hm³
Volume stored
974 hm³
Vs month average
116% of normal
Coordinates
33.670°N, 117.066°W
Last updated
2026-10-09
Current fill
98.7%vs 7 days ago
+0.1%gaining
vs 1 year ago
+2.7%year-over-year
7-day trend
→stable
Drought context
Storage vs October average
116%of normal
98.7% full on 2026-10-09, against an average of 85.4% for October across 6 years of readings (+13.3 points).
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: 2026-10-09.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 33.670, -117.066 · Open in Google Maps
About DIAMOND VALLEY
As of October 9, 2026, DIAMOND VALLEY is filled to 98.7% of its total capacity, holding roughly 974 hm³ of water out of a maximum 987 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (+0.1 pts), and it is 2.7 points above its level on the same date a year earlier.
Across the readings we hold for DIAMOND VALLEY — 1812 data points between October 16, 2021 and October 9, 2026 — the level has ranged from a low of 60.8% (March 10, 2023) to a high of 99.4% (February 18, 2025). On average the reservoir is fullest around September and at its lowest around March.
It is operated by CDEC primarily for multiple purposes. It lies within the California basin at 33.670°N, 117.066°W.
Key facts
- Current fill level
- 98.7%
- Water stored
- 974 hm³
- Total capacity
- 987 hm³
- 7-day change
- ▲ 0.1 pts
- Year-on-year
- ▲ 2.7 pts
- Primary use
- Multipurpose
- River basin
- California
- Operator
- CDEC
- Coordinates
- 33.670°N, 117.066°W
- Last updated
- October 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Oct 2026 | 98.7% | 974 |
| 8 Oct 2026 | 98.7% | 974 |
| 7 Oct 2026 | 98.7% | 974 |
| 6 Oct 2026 | 98.6% | 973 |
| 5 Oct 2026 | 98.6% | 973 |
| 4 Oct 2026 | 98.6% | 973 |
| 3 Oct 2026 | 98.6% | 973 |
| 2 Oct 2026 | 98.6% | 973 |
| 1 Oct 2026 | 98.5% | 972 |
| 30 Sep 2026 | 98.6% | 973 |
| 29 Sep 2026 | 98.5% | 972 |
| 28 Sep 2026 | 98.5% | 972 |