WashingtonReservoir, 3,837 acres
Lake Merwin water level
Current level
229.00ft NGVD29
Reading from Oct 26, 2026
Well below normal for October
- Past 24 hours
- -0.56ft
- Past 7 days
- -0.15ft
- Past 30 days
- 0.00ft
- vs typical October
- -6.44ft
Lake Merwin was at 229.00 ft on October 26, falling 0.15 ft over the past week. That is well below normal for October: the typical October level is 235.44 ft, so the lake is 6.44 ft below its usual mark.
Last 30 days
Shaded band shows the lowest and highest October monthly averages on record. Dashed line is the typical October level.
Typical level through the year
Each bar spans the range of monthly averages on record for that month. The line marks the median. The orange dot is where the lake sits now.
Recent daily readings
| Date | Level (ft NGVD29) | Change |
|---|---|---|
| Oct 24, 2026 | 229.56 | +0.73 |
| Oct 23, 2026 | 228.83 | +0.08 |
| Oct 22, 2026 | 228.75 | -0.23 |
| Oct 21, 2026 | 228.98 | +0.79 |
| Oct 20, 2026 | 228.19 | -0.96 |
| Oct 19, 2026 | 229.15 | +0.05 |
| Oct 18, 2026 | 229.10 | -0.38 |
| Oct 17, 2026 | 229.48 | -0.52 |
| Oct 16, 2026 | 230.00 | 0.00 |
| Oct 15, 2026 | 230.00 | 0.00 |
| Oct 14, 2026 | 230.00 | 0.00 |
| Oct 13, 2026 | 230.00 | +0.17 |
| Oct 12, 2026 | 229.83 | +0.04 |
| Oct 11, 2026 | 229.79 | -0.21 |
Reading these numbers
Readings are elevations in feet above the National Geodetic Vertical Datum of 1929 (NGVD29), the reference most older dam and lake charts use. If you compare with a newer chart in NAVD88, expect a difference of a few feet. Our glossary explains NGVD29 vs NAVD88.
On a reservoir, a few feet of drop changes the shoreline more than you would think. Low water exposes stumps, sandbars and old roadbeds that are normally well under the hull, and some ramps end before the water does.
High water brings its own problems: floating debris after storms, flooded docks and courtesy piers, and no-wake rules near flooded campgrounds. A quick look at the trend before you hitch up saves a wasted trip.
The gauge is about 8 miles from the center of the lake and is listed by USGS as Lake Merwin near Chelatchie, WA. Wind can pile water up at one end of a big lake for a few hours, so short spikes on a windy day are normal.
Lake Merwin water level questions
What is the water level at Lake Merwin today?
Lake Merwin was at 229.00 ft on October 26, falling 0.15 ft over the past week. That is well below normal for October: the typical October level is 235.44 ft, so the lake is 6.44 ft below its usual mark.
Is Lake Merwin high or low right now?
Compared with the long-term record for October, the lake is well below normal. The October monthly average has ranged from 229.88 to 238.04 ft, with a typical value of 235.44 ft.
Is Lake Merwin rising or falling?
Over the last seven days the level has fallen (-0.15 ft), and it is 0.00 ft compared with 30 days ago.
Where does the Lake Merwin water level data come from?
From the U.S. Geological Survey, gauge 14219950 (Lake Merwin near Chelatchie, WA). USGS publishes provisional readings every 15 to 60 minutes; they can be revised later after quality checks.
How often is this page updated?
The page itself is rebuilt every day with the latest daily values, and the current reading refreshes straight from the USGS each time you open it.
Nearby lakes
If Merwin is blown out, these are the closest alternatives. Tap through for their water levels.