Lake Cascade

Idaho

Lake Cascade 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

11.8 feet below full pool

−11.80 ft vs full pool

7-day trend
Falling
7-day change
Down 0.20 ft
30-day change
Down 0.20 ft
Last updated
Sep 10 • 12:00 AM

Lake Cascade is currently 11.8 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

Valley County, ID · surrounding county from lake location

Abnormally Dry

The surrounding county is abnormally dry, which is not official drought.

Severity

NoneExtreme

Weekly trend

Improving

Compared with last week

Official drought

Yes

1.9% 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 Valley County, ID

Key Facts

Managing authority

Waterbody / project type

Reservoir

Official purposes

Hydroelectric · IrrigationSource: National Inventory of Dams

Full pool

4828.00 ft

Datum

NGVD29 · MSL

Current-level source

U.S. Bureau of Reclamation (USBR)

Project / NID identifier

Cascade Dam · ID00283

Dam / watershed (NID design values)

Static design values from a confidently matched National Inventory of Dams record — not live gage readings.

Max storage
860,000 acre-ft
Surface area at normal pool
27,700 acres
Drainage area
615 sq mi
Spillway capacity (design)
12,500 cfs
Dam structure
Rockfill · 110 ft high · completed 1948
Hazard classification
High
Safety & inspection
last inspection Oct 28, 2020

National Inventory of Dams · matched record: Cascade Dam (ID00283)

How this lake is operated

  • Documented project purposes (National Inventory of Dams): Hydroelectric, Irrigation.

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
4828.00 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.

How we source lake data · Glossary

Common questions about Lake Cascade

Who manages Lake Cascade?
Lake Cascade 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 Lake Cascade?
The published full-pool elevation for Lake Cascade is 4828.00 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 Lake Cascade?
Lake Insights displays the latest available elevation for Lake Cascade 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 Lake Cascade?
Elevations for Lake Cascade are referenced to NGVD29 (MSL).
What are the documented purposes of Lake Cascade?
Documented purposes for Lake Cascade (National Inventory of Dams): Hydroelectric, Irrigation.

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