Lake Mead critical elevation guide

Lake Mead Minimum Power Pool: 950 Feet Explained

Reclamation identifies elevation 950 feet above mean sea level as Lake Mead's estimated minimum power pool: the lower boundary for generating hydropower through Hoover Dam's turbines.

Lake Projections reference guide

In brief

What this elevation does—and does not—mean

  • Reclamation calls 950 feet the estimated minimum power pool and the top of inactive pool.
  • Below this elevation, water cannot be passed through the turbines for generation, but releases can continue through the river outlet works.
  • Minimum power pool is 55 feet above Hoover Dam's 895-foot dead pool.
Schematic Lake Mead elevation scale placing the Minimum power pool at 950 ft among Hoover Dam's three low-elevation thresholds
950 ft in context with the other Hoover Dam thresholds. Lake Projections schematic based on elevations in Reclamation's July 2026 Final EIS, Technical Appendix 15.

What minimum power pool means

Minimum power pool is the lowest reservoir elevation at which a hydropower plant can produce electricity. For Hoover Dam, Reclamation currently uses an estimated elevation of 950 feet above mean sea level.

Generation capability declines before Lake Mead reaches that line as hydraulic head decreases and fewer turbines remain suitable for use. The threshold identifies the lower physical boundary; it is not a claim that output stays constant above it.

Why the threshold moved from 1,050 to 950 feet

Between 2011 and 2016, Reclamation installed five wide-head turbines at Hoover Dam. Its 2022 reservoir-capacity allocation says those units extended the estimated lower elevation for safe turbine generation from 1,050 feet to 950 feet.

That history is why older references may still associate 1,050 feet with minimum power pool. The current Reclamation allocation sheet and July 2026 Final EIS use 950 feet.

What happens between 950 and 895 feet

Below 950 feet, releases can no longer pass through the turbines for hydropower. Reclamation describes elevations from 950 down to 895 feet as inactive pool, where releases can continue through the river outlet works but face low-elevation constraints.

This distinction matters when reading forecasts: a projection below minimum power pool is a hydropower warning, but it is not yet a projection below dead pool.

Primary references

Sources

Forecasts are planning information, not guaranteed outcomes. Use official Reclamation notices for current operating decisions.