Reservoir · Washington · United States · USGS NWIS
Mayfield Reservoir
96.5% full
Capacity
164.94 hm³
Volume stored
159 hm³
Coordinates
46.503°N, 122.588°W
Last updated
2026-07-15
Current fill
96.5%vs 7 days ago
-0.6%losing
vs 1 year ago
+0.5%year-over-year
7-day trend
→stable
Data source: USGS National Water Information System (NWIS) — 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: 2026-07-15.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 46.503, -122.588 · Open in Google Maps
About Mayfield Reservoir
As of July 15, 2026, Mayfield Reservoir is filled to 96.5% of its total capacity, holding roughly 159 hm³ of water out of a maximum 165 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-0.6 pts), and it sits close to where it was a year earlier.
Across the readings we hold for Mayfield Reservoir — 1432 data points between August 14, 2022 and July 15, 2026 — the level has ranged from a low of 88.8% (December 9, 2025) to a high of 99.5% (March 13, 2026). On average the reservoir is fullest around June and at its lowest around November.
It is operated by USGS primarily for multiple purposes. It lies within the Washington basin at 46.503°N, 122.588°W.
Key facts
- Current fill level
- 96.5%
- Water stored
- 159 hm³
- Total capacity
- 165 hm³
- 7-day change
- ▼ 0.6 pts
- Year-on-year
- ▲ 0.5 pts
- Primary use
- Multipurpose
- River basin
- Washington
- Operator
- USGS
- Coordinates
- 46.503°N, 122.588°W
- Last updated
- July 15, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 15 Jul 2026 | 96.5% | 159 |
| 14 Jul 2026 | 96.5% | 159 |
| 13 Jul 2026 | 96.2% | 159 |
| 12 Jul 2026 | 96.8% | 160 |
| 11 Jul 2026 | 97.1% | 160 |
| 10 Jul 2026 | 97.9% | 161 |
| 9 Jul 2026 | 98.3% | 162 |
| 8 Jul 2026 | 97.1% | 160 |
| 7 Jul 2026 | 98.2% | 162 |
| 6 Jul 2026 | 96.8% | 160 |
| 5 Jul 2026 | 95.8% | 158 |
| 4 Jul 2026 | 96.5% | 159 |
Frequently asked questions
What is the current water level of Mayfield Reservoir?
As of July 15, 2026, Mayfield Reservoir is at 96.5% of its capacity, holding approximately 159 hm³ of water, according to USGS NWIS data.
Is Mayfield Reservoir reservoir full?
Mayfield Reservoir is essentially full, sitting at 96.5% of capacity as of July 15, 2026.
Is the water level at Mayfield Reservoir rising or falling?
The level at Mayfield Reservoir has been broadly stable over the latest week on record (-0.6 points).
How much water can Mayfield Reservoir hold?
Mayfield Reservoir has a total capacity of 165 hm³.
Where is Mayfield Reservoir reservoir located?
Mayfield Reservoir is located in Washington, United States, within the Washington basin (coordinates 46.503°N, 122.588°W).
What is Mayfield Reservoir used for?
Mayfield Reservoir is used primarily for multiple purposes, and is managed by USGS.