This blog explores the history of Phoenix, Arizona and a little bit of Los Angeles and San Francisco, California. This blog is not supported by advertising, it's supported by the generosity of my patrons on Patreon. Thank you!

Streets as storm drains in Phoenix, Arizona

The first thing that I noticed when I moved to Phoenix from Minneapolis is that it didn't rain much. And when it did rain, the streets flooded. I grew up in a city with a lot of rain, and a lot of melted snow, and just took it for granted that it all just went away somewhere, I wasn't sure where. What I came to discover was a thing called storm drains.

Storm drains are not sewers. They are simply drains buried under a street that allow rainwater to flow away. In Los Angeles, I often saw little reminders stenciled into the storm drains along the curbs that all water flowed to the ocean. Which meant, no dumping of toxic chemicals, like anti-freeze. I'm sure if I had stayed in Minnesota, I would have never been made aware of the idea of storm drains, but since I watched the streets of Phoenix turn into lakes whenever it rained, I started wondering about it.

As everyone in Phoenix knows, it never rains in the desert. Of course, until it does. And it does with some wicked downpours every summer, called "monsoons". But even a gentle rain was enough to flood the streets in Phoenix when I first moved here as a teenager. And I came to realize that many of the streets were themselves designed to act as storm drains.

I collect old Photos of Phoenix and am absolutely amazed at how the streets were themselves designed as storm drains. The curbs were ridiculously high, and when it rained, the streets filled up, and the water flowed away. The Salt River Valley, although it looks flat, has a gentle slope toward the southwest, so eventually all of the rain will go into the Salt, and Gila Rivers. And Arizona itself tilts so that the water eventually makes its way to the Gulf of California. Yes, it all flows to the ocean.

Shirley Christy in front of the Adams Hotel, Central and Adams, in 1903. Notice the high curbs.

When Phoenix was young, all they did was build high curbs, hope that it didn't rain much, and wait for the water to flow away. That's part of the reason that the southwestern valley became a less desirable place to live than the northeastern valley. If you've ever ridden a bike, you know that it's uphill from downtown Phoenix to Glendale. In a car, it's barely noticeable, but it's enough of a tilt that the water, which prefers to flow downhill, will flow away. And the idea was to keep the water out of buildings, and in the streets, where it could flow away without doing any real damage. When you think about this, this kind of makes senses, and is the most economical thing to do.

The problem with using streets as storm drains is that after a hard rain, it takes a while for the water to flow away. It may only take a few hours for the streets to clear, but in the meantime, people are driving though lakes, which is dangerous.

So if you've lived in the Phoenix area in the past few decades, you have seen a lot of storm drains being installed. It requires digging up the street along the edges and burying gigantic drains. The idea, of course, is to get the water off of the street, and into the drains, where it can flow away at its leisure. In some parts of the valley, like where I live, this has already been done. Of course, nobody likes road construction, where two lanes are squeezed down into one. But once the engineering on the storm drains is finished, flooded streets in Phoenix will pass into history. But it's going to take some time!

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