Lake Mead Elevation Currently 1048 Feet Above Sea Level' - At 1035' Its Generating Capacity Falls By 70%

[hatrack]

4. The generating capacity of all dams falls as water levels fall . . .

Last edited Sun Jun 14, 2026, 12:39 PM - Edit history (1)

At Glen Canyon, they've already had to substantially replace/repair most of the turbine blades in a multi-year process.

This is kind of an oversimplification, but the lower the elevation of water above the penstocks, the lower the water pressure, and as pressure drops, cavitation risk increases.

Formation of air bubbles on turbine blades (or on spillway walls, as the same dam experienced during emergency high-water conditions in 1983) produces micro-explosions capable of eroding metal, concrete and rock.

Main point - if the water gets low enough - i.e. if there isn't enough water above the penstocks to generate power without cavitation risk, you have to limit and/or shut down generation even if there's still enough water to flow through the penstocks.