Reservoir · California · United States · CDEC
HELL HOLE
48.5% full
Capacity
255.33 hm³
Volume stored
124 hm³
Coordinates
39.058°N, 120.407°W
Last updated
2026-09-16
Current fill
48.5%vs 7 days ago
-3.0%losing
vs 1 year ago
-8.7%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: 2026-09-16.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 39.058, -120.407 · Open in Google Maps
About HELL HOLE
As of September 16, 2026, HELL HOLE is filled to 48.5% of its total capacity, holding roughly 124 hm³ of water out of a maximum 255 hm³. At this level the reservoir is within its normal operating range.
Over the most recent week on record the fill level has fallen by 3.0 percentage points, and it is 8.7 points below its level on the same date a year earlier.
Across the readings we hold for HELL HOLE — 1822 data points between September 19, 2021 and September 16, 2026 — the level has ranged from a low of 26.4% (October 16, 2021) to a high of 101.3% (May 21, 2023). On average the reservoir is fullest around June and at its lowest around December.
It is operated by CDEC primarily for multiple purposes. It lies within the California basin at 39.058°N, 120.407°W.
Key facts
- Current fill level
- 48.5%
- Water stored
- 124 hm³
- Total capacity
- 255 hm³
- 7-day change
- ▼ 3.0 pts
- Year-on-year
- ▼ 8.7 pts
- Primary use
- Multipurpose
- River basin
- California
- Operator
- CDEC
- Coordinates
- 39.058°N, 120.407°W
- Last updated
- September 16, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 16 Sep 2026 | 48.5% | 124 |
| 15 Sep 2026 | 48.6% | 124 |
| 14 Sep 2026 | 48.4% | 124 |
| 13 Sep 2026 | 49.0% | 125 |
| 12 Sep 2026 | 49.7% | 127 |
| 11 Sep 2026 | 50.3% | 128 |
| 10 Sep 2026 | 50.9% | 130 |
| 9 Sep 2026 | 51.5% | 131 |
| 8 Sep 2026 | 52.0% | 133 |
| 7 Sep 2026 | 52.6% | 134 |
| 6 Sep 2026 | 53.3% | 136 |
| 5 Sep 2026 | 53.9% | 138 |