Alder Lake
Alder Lake is managed by Tacoma Power. Lake Insights displays its latest available elevation from USGS Water Data (daily values).
Lake Status
- Last updated
- Aug 24 • 5:00 PM
Watershed drought conditions
Pierce County, WA · surrounding county from lake location
Abnormally Dry
The surrounding county is abnormally dry, which is not official drought.
Severity
Weekly trend
Stable
Compared with last week
Official drought
Yes
6.8% of the watershed is currently classified as official drought (D1+).
U.S. Drought Monitor · map date Sep 8, 2026. Updated weekly. droughtmonitor.unl.eduView drought map for Pierce County, WA
Key Facts
Managing authority
Waterbody / project type
Current-level source
Why the level can change
General factors for reservoirs like this
These are common influences for this type of lake. They do not identify the cause of a specific current change unless an operator update confirms it.
Rainfall & inflows
Rain and upstream river inflows can raise reservoir levels, especially after storms.
Downstream releases
When an operator releases water through a dam, reservoir storage can fall and downstream flows can rise.
Flood-risk operations
Some projects store or release water under flood-risk rules when conditions require it.
Water supply
Some reservoirs support municipal, industrial, irrigation, or regional water-supply needs.
Hydropower
Hydropower projects may pass water through turbines when generating electricity.
Seasonal weather
Dry periods, heat, evaporation, and seasonal rainfall patterns can affect storage over weeks and months.
Current data source
Managing authority: Tacoma Power
Observation source used by Lake Insights: USGS Water Data (daily values)
Who manages the lake and who publishes the reading Lake Insights displays can differ. Lake Insights does not invent a source label from the managing authority alone.
General education
Shared background — not lake-specific facts
Lake Insights aggregates water level information from authoritative public sources such as the U.S. Army Corps of Engineers, NOAA, TVA, Bureau of Reclamation, power utilities, and other official lake operators. We preserve historical observations, calculate trends, and present lake conditions in a consistent format. For USGS Water Data (daily values), we link to the official source whenever it is available. Lake Insights does not predict future lake levels unless an official forecast has been published by the managing authority.
Common questions about Alder Lake
- Who manages Alder Lake?
- Alder Lake is managed by Tacoma Power. Lake Insights reports published gauge readings; it does not operate the waterbody.
- Where does Lake Insights get the level reading for Alder Lake?
- Lake Insights displays the latest available elevation for Alder Lake from USGS Water Data (daily values). The managing authority (Tacoma Power) may differ from the agency that publishes the observation used on this page.