The difference between Phoenix and the other desert cities - water
Although you really can't see it now, Phoenix was established in a floodplain. Like the Nile in Egypt, the Salt River has been doing a yearly flood, bringing a massive amount of water and fertile soil into the valley. The Hohokams knew that, and so did the Phoenix pioneers. The water flowed right past them, and it was just a question of grabbing it as it went by, and storing it. And of course, not getting washed away. It's still true today.
The water for Phoenix doesn't come from miles away, it flows right through the valley, as it has been doing since the formation of the Salt River Valley and the uplift of the area northeast of it. Take a look at a relief map, run your finger over the areas around the Mogollon Rim. When it rains up there, the water flows downhill, south by southwest, through the Salt River Valley. But the most water flows after the snows melt. So the water comes crashing through in spring.
This combination of fertile soil and a steady supply of water, free for the taking, is what made Phoenix so successful. It was never a question of a lack of water, it was a question of controlling it, and storing it. And so a series of privately-funded dams were built on the Salt River, although they were never enough. It wasn't until a Federally-funded project built the Roosevelt Dam in 1911 that anything really big enough was built to at least try to control the water.
Now don't get me wrong, just because I live in Phoenix doesn't mean that I waste water. I still have to pay for it. It has to be stored, cleaned, and delivered. I have xeriscape plantings here at my house. I don't have grass. But that's mostly because I'm not interested in paying a lot for water use. The water itself is not in short supply. And if you can't see that in your day-to-day life in Phoenix, it's thanks to the hard work of the Maricopa County Flood Control District.
Pictured above: map of the area that supplies water, and flooding, to the Salt River Valley.
Posted by Brad Hall