Comment by jjk166

> The city needs 1.2 billion m3 cubic meters of fresh water, and is on average 1200 meters above sea level. Let's not even count actually transporting that water, let's just discuss pumping it.

> E = mgh, blabla, this requires 500 Megawatt constant power, 24/7/365, JUST to move the water up. This is the theoretical minimum power required to lift it against gravity. Does not include pumping the water inland.

The energy required to lift that water does not give you a power requirement, which is a rate that energy is consumed. Tehran has a water deficit of 101 million m3 per year which would require 38 MW to lift. That's a couple of wind turbines worth of power. Obviously there's a lot more to keeping the water system working, but you're off by an order of magnitude. Building a small power plant to keep a city of that size habitable is certainly achievable.

> And for Asian cities, Teheran is tiny, about the size of Greater London or Paris. Most Pakistani cities are easily double that.

Tehran's urban area is the 29th most populous in the world with over 14 million people. Pakistan has one larger urban area, Karachi, which is 40% larger.