Castle Lake water level — Washington
Castle Lake in Washington was last measured at 2,577.54 ft (datum NGVD29), as of Aug 31, 2026, 12:45 AM (UTC-07:00) (USGS Water Services). Over its recent trend window the level has been falling (−0.1 ft). This reading is provisional and subject to revision.
- % of conservation pool full
- Not reported
- Storage
- Not reported
- Recent trend
- ↓Falling
−0.1 ft over the trend window
Recent trend
Readings this station published between Jun 24, 2026 and Aug 31, 2026 — a 67-day window — downsampled for display.
Data: USGS Water Services (waterservices.usgs.gov) and USACE CWMS Data (cwms-data.usace.army.mil), retrieved 2026-08-31. Both public domain (a work of the U.S. Government, 17 U.S.C. §105).
Source: USGS site 14240446, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00). Official page for this lake →
About this gauge's record
This site's drainage basin covers approximately 3 sq mi of contributing watershed.
The dam behind Castle Lake
Castle Lake is held back by Castle Lake Debris Dam , an earthfill embankment, holding the pool back by sheer mass and an impervious core rather than by the strength of concrete , standing 190 ft high and running 2,000 ft along its crest in Cowlitz County , near KID VALLEY . It was completed in 1980 , and is owned by USDA FS (a federal owner) .
Its recorded primary purpose is other .
Its spillway is ungated: once the pool reaches the crest, water leaves on its own and the operator cannot hold it back. The spillway opening is 100 ft wide.
NID has not assigned it a hazard potential classification. It has not been assigned a condition rating.
At its normal pool the reservoir covers about 480 acres. NID records a maximum storage of 19,000 acre-ft against a normal storage of 19,000 acre-ft.
Dam facts: National Inventory of Dams record WA00772 , filed by Forest Service — U.S. Army Corps of Engineers, public domain. Water levels above come from USGS Water Services and are a separate source. (How this dam was matched to this gauge →)
How Castle Lake compares nearby
2 of 6 nearby lakes with a current trend are also falling right now.
Nearby lakes
The six nearest published lakes by centroid distance (great-circle) — cross-state neighbors included.
| Lake | State | Level | Distance |
|---|---|---|---|
| Spirit Lake West at Spirit Lake | WA | 3,441.68 ft | 8 km |
| Spirit Lake at Tunnel at Spirit Lake | WA | 3,400.49 ft | 9 km |
| Swift Reservoir 3.2 Mi East of Dam | WA | 966.00 ft | 24 km |
| Yale Reservoir | WA | 474.00 ft | 25 km |
| Lake Merwin | WA | 235.00 ft | 33 km |
| Bull Run Reservoir No 1 | OR | 1,010.92 ft | 87 km |
Frequently asked questions
- What is the current water level of Castle Lake?
- As of Aug 31, 2026, 12:45 AM (UTC-07:00), the pool elevation was 2,577.54 ft (datum NGVD29), provisional and subject to revision. See the trend chart above for the recent direction.
- Is Castle Lake full right now?
- Its managing agency does not publish a %-of-conservation-pool-full figure for this lake, so we show the bare level rather than estimate one.
- Where does this data come from?
- From USGS site 14240446, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00).
More in Washington
See every lake tracked in Washington, or read the methodology behind these figures.