Phoenix is the 5th largest city in the United States. It has a city proper population of about 1.6 million people and a metro area population of close to 5 million. It is also one of the fastest growing cities in the US.

But being the desert city that it is, its population consumes more water than its natural aquifers can support. Which is why there is something called the Central Arizona Project (CAP).

Approved in 1968, the CAP diverts water from the Colorado River into the state of Arizona. The system is 336 miles (or 541 km) and it runs from Lake Havasu to Tucson, via Phoenix.

Here is an aerial image of the canal from Wikipedia Commons:

And here is a system map from CAP:

Today, it is the single largest water source (and consumer of power) in Arizona, serving about 80% of the state's population. This obviously makes it invaluable. It delivers on average about 1.5 million acre-feet of water per year. (Acre-foot = Acre of area x one foot in depth.)

I was reading about this project today and I found it fascinating. Maybe some of you will too.