Trinity Lake
Trinity Lake is managed by U.S. Bureau of Reclamation. Lake Insights displays its latest available elevation from U.S. Bureau of Reclamation (USBR). Published reference elevations are listed below.
Lake Status
47.76 feet below full pool
−47.76 ft vs full pool
- 7-day trend
- Falling
- 7-day change
- Down 0.65 ft
- 30-day change
- Down 0.65 ft
- Last updated
- Sep 10 • 1:00 AM
Trinity Lake is currently 47.76 feet below full pool and has fallen slightly over the past week. Readings show continued drawdown relative to full pool, with levels trending lower over the past week.
Watershed drought conditions
Trinity County, CA · 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
9.4% 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 Trinity County, CA
Key Facts
Managing authority
Waterbody / project type
Official purposes
Full pool
Datum
Current-level source
Project / NID identifier
Dam / watershed (NID design values)
Static design values from a confidently matched National Inventory of Dams record — not live gage readings.
- Normal storage
- 2.45M acre-ft
- Max storage
- 2.76M acre-ft
- Surface area at normal pool
- 17,722 acres
- Drainage area
- 692 sq mi
- Spillway capacity (design)
- 22,400 cfs
- Dam structure
- Earth · 538 ft high · completed 1962
- Hazard classification
- High
- Safety & inspection
- last inspection Apr 20, 2022
National Inventory of Dams · matched record: Trinity Dam (CA10196)
How this lake is operated
- Documented project purposes (National Inventory of Dams): Hydroelectric, Irrigation, Recreation.
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.
Published reference elevations
- Full pool
- 2370.00 ft
Published reference elevation. Not necessarily a fixed year-round target for every project.
Current data source
Managing authority: U.S. Bureau of Reclamation
Observation source used by Lake Insights: U.S. Bureau of Reclamation (USBR)
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 U.S. Bureau of Reclamation (USBR), 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 Trinity Lake
- Who manages Trinity Lake?
- Trinity Lake is managed by U.S. Bureau of Reclamation. Lake Insights reports published gauge readings; it does not operate the waterbody.
- What is full pool at Trinity Lake?
- The published full-pool elevation for Trinity Lake is 2370.00 ft (NGVD29). Full pool is a published reference elevation — not a prediction of today’s level.
- Where does Lake Insights get the level reading for Trinity Lake?
- Lake Insights displays the latest available elevation for Trinity Lake from U.S. Bureau of Reclamation (USBR). The managing authority (U.S. Bureau of Reclamation) may differ from the agency that publishes the observation used on this page.
- What datum is used for Trinity Lake?
- Elevations for Trinity Lake are referenced to NGVD29 (MSL).
- What are the documented purposes of Trinity Lake?
- Documented purposes for Trinity Lake (National Inventory of Dams): Hydroelectric, Irrigation, Recreation.