Lake Mead and Hoover Dam

Year completed

Completed in 1936, one of the largest engineering projects of its time.

Lake Mead capacity

Full capacity of 35 km³ (the largest reservoir in the USA).

Hydropower output

Generates around 4 billion kWh of electricity per year — enough for 1.3 million people.

States supplied

Supplies water to Nevada, Arizona, California, and parts of Mexico.

Las Vegas dependence

Las Vegas gets 90% of its water from Lake Mead.

Decline in water level

Lake Mead has fallen to historic lows, dropping over 45 metres since 2000.

Over‑abstraction

Colorado River allocations exceed natural flow by 1.2-1.5 times in dry years.

Drought duration

The Southwest is in a 20+ year megadrought, the worst in 1,200 years (tree‑ring data).

Population pressure

The region's population has grown by 45% since 1990, increasing demand on Lake Mead.

Evaporation losses

Lake Mead loses >800 million m³ of water per year to evaporation.

Minimum power pool

If water drops below 327 m elevation, Hoover Dam cannot generate electricity.

Dead pool risk

At 270 m elevation, water can no longer flow through the dam — a "dead pool" scenario.

Agricultural dependence

Colorado River irrigates 5.5 million acres of farmland — 15% of US crops.

Urban demand

Cities like Phoenix, LA, and Las Vegas rely on the river for 40 million people.

Siltation issue

Sediment reduces reservoir capacity by ~0.2% per year.