Reservoir · Washington · United States · USGS NWIS
Howard A. Hanson Reservoir
32.9% full
Capacity
92.76 hm³
Volume stored
31 hm³
Coordinates
47.277°N, 121.785°W
Last updated
2026-09-30
Current fill
32.9%vs 7 days ago
-3.4%losing
vs 1 year ago
+16.5%year-over-year
7-day trend
↓falling
Data source: USGS National Water Information System (NWIS) — daily reservoir storage volume. Design capacity is unavailable for this site, so fill % is estimated against the 5-year maximum storage and may overstate fullness. Last reading: 2026-09-30.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 47.277, -121.785 · Open in Google Maps
About Howard A. Hanson Reservoir
As of September 30, 2026, Howard A. Hanson Reservoir is filled to 32.9% of its total capacity, holding roughly 31 hm³ of water out of a maximum 93 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has fallen by 3.4 percentage points, and it is 16.5 points above its level on the same date a year earlier.
Across the readings we hold for Howard A. Hanson Reservoir — 1447 data points between October 1, 2022 and September 30, 2026 — the level has ranged from a low of 0.1% (January 23, 2023) to a high of 100.0% (December 12, 2025). On average the reservoir is fullest around June and at its lowest around January.
It is operated by USGS primarily for multiple purposes. It lies within the Washington basin at 47.277°N, 121.785°W.
Key facts
- Current fill level
- 32.9%
- Water stored
- 31 hm³
- Total capacity
- 93 hm³
- 7-day change
- ▼ 3.4 pts
- Year-on-year
- ▲ 16.5 pts
- Primary use
- Multipurpose
- River basin
- Washington
- Operator
- USGS
- Coordinates
- 47.277°N, 121.785°W
- Last updated
- September 30, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 30 Sep 2026 | 32.9% | 31 |
| 29 Sep 2026 | 33.3% | 31 |
| 28 Sep 2026 | 33.9% | 31 |
| 27 Sep 2026 | 34.4% | 32 |
| 26 Sep 2026 | 34.9% | 32 |
| 25 Sep 2026 | 35.3% | 33 |
| 24 Sep 2026 | 35.7% | 33 |
| 23 Sep 2026 | 36.3% | 34 |
| 22 Sep 2026 | 36.8% | 34 |
| 21 Sep 2026 | 37.4% | 35 |
| 20 Sep 2026 | 37.8% | 35 |
| 19 Sep 2026 | 38.3% | 36 |