We leave town for a few days and the sky is falling.  Two inches of rain in less than two hours! That sounds unheard of but that is typical for our Monsoon storms here in the Valley and elsewhere in Arizona.  Watching these videos and walking around in the subsequent drizzle last night I could only think of the comments made on James’ previous posts on rainwater harvesting.  There will always be naysayers but seriously folks, just think if we had a plan going into this to harvest all of that water instead of just directing it back to the Salt River, along with all of the trash on the highway.

Even if we just applied rain water collection techniques to the Arizona State University Campus, near where the news video was taken it could make a huge difference. Lets figure out what we could have saved.  If we estimate the ASU main campus to be about a square mile and say the rain is falling at about 2 inches per hour (50.88mm) then in one hour we could have collected ~34 million gallons of water! This sounds completely unbelievable, but according to this USGS page it is true. For information on collecting rainwater from your own property take a look at the Rainwater Harvesting for Drylands website.

Apart from thinking of water use I must admit I had a serious case of schadenfreude watching the youtube video. We have only a few poorly distributed storm sewers here in the desert and little to no culverts diverting water under roadways and this leads to flooding of streets on a predictable yearly basis.  It does not take much water or current to not only stop a car but to carry it off coarse stranding the driver.  The best bet is to not drive in flood waters at all, take a break, wait it out. It is still the desert and things run off and soak up within a relatively short amount of time.  I wasn’t the one waiting in that traffic though so I can see the desire if there is no other way and you’re in a hurry.  Admittedly, I kept hoping we would see them get stuck. I know, I know, it is awful for me to think that but really it takes very little to get your car stuck.  If your engine doesn’t cut off from getting wet it is easy to lose traction. A car only needs an inch or two to become buoyant and then even the slightest current can carry it off the road or into another car where it can be stranded while waters potentially continue to rise.  Hence the Stupid Motorist Law where people have to pay for their own rescue.. think this is atypical? Think again.

Here’s a video of what happens when the freeway floods and traffic is stopped dead in its tracks.
http://www.kpho.com/video/16871937/index.html

Video of a wash during this storm.

Photo by: Bradley Cornelius Groot

The bleaching of the world’s coral reefs has been an increasingly concerning mystery in recent years.  Healthy corals harbor a host of zooxanthelae, colorful algae that live symbiotically within the coral tissue providing energy to the coral.  The coral in turn provides shelter, plenty of carbon dioxide for photosynthesis, nutrients, and protection.  When the corals are “bleached” these necessary algae are expelled leaving only the shell of the coral, its white, bleached skeleton.  Scientists for years have struggled trying to identify a cause for this. Climate change is still a major contender but National Geographic just came out with an article that suggests something else, sunscreen.

“Four commonly found sunscreen ingredients can awaken dormant viruses in the symbiotic algae called zooxanthellae that live inside reef-building coral species.

The chemicals cause the viruses to replicate until their algae hosts explode, spilling viruses into the surrounding seawater, where they can infect neighboring coral communities. “

Those four ingredients are as follows:

1. Parabens
2. Cinnamate
3. Benzophenone
4. “A camphor derivative” (likely methylbenzylidene camphor)

Parabens in particular are in all sorts of other products, even our food.  If they are the culprits in this fiasco we have a lot more to worry about other than just sunscreens. With growing concern around them I suggest reading all of your product labels and seeking out companies that are paraben-free. Even some main stream companies are transitioning over to paraben-free now so it should be getting easier in the near future.

The study is not the end all be all, it is just a step in the direction of possibly understanding this phenomena. It isn’t that hard to find a sunscreen that is made with physical sunblock rather than chemical sunblocks. Look for titanium dioxide or zinc oxide on the ingredient list and avoid the ingredients listed above.  If all else fails put on a long sleeved white shirt and a giant hat.. you may look silly but you won’t get burned and you just might make a difference.

Every time I post about rainwater harvesting I get people saying things like “yeah, but it never rains” or “it doesn’t rain enough here,” so I wanted to post up some pictures from earlier this week after we had a freak rain storm that dropped a little over a inch of rain. This is Santa Rosa Wash, it is just down the street from where I live, it flows from the south to the north so whenever Tucson get a lot of rain it floods. This kind of seems like a cruel joke because Tucson could probably use this water more than Phoenix. This flooding subsided within 24 hours of its start, but it is still lightly flowing.

I’ve seen pictures of downtown Maricopa underwater from what I think was a 100 year flood, but I can seem to find any for this post. If you have any of these pictures, send us links in the comments. According to FEMA maps our house is above the flood plain, but I imagine when Maricopa gets another 100 year flood it is going to do some damage nearby. I’m not sure I’d want to live on the banks of this wash when that happens.

It wouldn’t be a proper flooded wash if someone didn’t cross the road block and cross through it. It doesn’t take much water to get stuck, so be careful, that’s why Arizona has the stupid motorist law.

The “Stupid Motorist Law”, which corresponds to section 28-910 of the Arizona Revised Statutes, states that any motorist who drives around barricades to enter a flooded stretch of roadway may be charged for the cost of his/her rescue.

The need for the law came from the lack of storm sewers in the deserts of the Southwestern United States. Desert rains, usually associated with summer monsoons, and the flooding that comes with them tend to be short-lived. Many desert cities and towns don’t use culverts to channel minor washes (also known by the Spanish name arroyos) beneath the roadway. Only major washes and floodplains have bridges over them. Storm drains are spaced quite far apart when they are present at all. Consequently, during rain storms, storm runoff flows over the roadway. During hard, strong rain storms, the washes, underpasses, and areas around large storm drains can flow fast and deep enough to pick up an automobile and carry it downstream. During particularly strong floods, one might see a motorist stuck in the middle of a wash, sitting on the roof of a dead car submerged to the windows.

In such cases, if public emergency services (such as a fire department, or paramedics) are called to rescue the motorist and tow the vehicle out of danger, the cost of those services can be billed to the motorist.

[Wikipedia]

This rainwater harvesting vertical terrace is the brilliant idea of Ontario College of Art and Design Student Michael Tampilic and has been entered in the Rocket 2008 Industrial Design Graduation Show and Competition. The terrace connects up with a downspout from your house and stores water in a large tank to continuously water the plants over long periods of time. It does this by using cotton wicks to transport the stored water by capillary action. Not only is this great for saving water in a desert environment like most of us in Arizona live in, but it looks awesome and you don’t have to worry about watering.

Vert is a rain terrace: a rainwater harvester and vertical garden. This project establishes sustainable water practices through the harvesting of rain, and brings the advantages of a living wall to the backyard through vertical gardening. Vert alleviates a homes reliance on public utility systems while beautifying unused vertical space.

More info at the Rocket 2008 page and at Treehugger.com.

Related Post: [Rainwater Harvesting: A beginners guide.]

Rainwater is one of our society’s greatest forgotten urban resources. We design our developments to drain rainwater from our property turning streets in to rivers. From there, water is directed down storm drains and forgotten about. We’re literally letting billions of gallons of water drain away when much of it could be used to water our landscapes, beautify our neighborhoods, and reduce the heat island effect.

This past weekend I saw Brad Lancaster talk about rainwater harvesting at the Green Living Conference in Phoenix and was moved to start making some changes around my own house. He’s from Tucson and has transformed his house from basically an empty dirt lot to a desert oasis. He’s done all this by “planting” the rainwater in his yard and keeping it there for the plants and trees to use. Seeing his yard and what he’s done with his system of catching rainwater in a cistern, using gray water from his sinks, tub, and washing machine it sounds too overwhelming and expensive to do this yourself, and I was thinking “Yeah, if only I had the money.” He had some great advice though, start small and simple. That’s what I’m going to do today.

With one inch of rain there is 600 gallons of water for every 1000 Sq ft of land. I just looked up the Sq ft of my property and it is just over 5000 Sq ft. Where I live in the desert we average about 8 inches of rain a year which means over 24,000 gallons of water fall on our property a year. Unless you live in Yuma Arizona where they average 3 inches a year, you probably get more rain than the 8 inches I get. Lets see if we can make use of some of this and not let it all wash away.

First thing you should do is think about the last time it rained and where rainwater is collecting in your yard already. This should reveal some low spots that could be ideal for planting. In my yard I have one such low spot next to my house where water from the yard and roof drains to. Unsurprisingly this has turned out to be one of the easiest spots to grow anything in our yard. Now there is even catnip, lavender, sunflowers, and a little chamomile that planted themselves and are thriving.

Second take a look around and see what you already have planted. Is water able to flow to them when it rains? Is there a basin the water can fill to water the plant? In my yard I have a grapefruit tree with a little berm around it. This is pretty good to hold in water from the hose, but when it rains it blocks any water from filling it. This probably should have been obvious, but I never really thought about it. The tree also has not really grown much in the two years it’s been there, I think it’s pretty much been stunted. Maybe it hasn’t had enough water? This morning I pulled out the shovel and started digging out the berm and creating a basin instead. Ideally this should have been done when I planted it a couple years ago, but better late than never. I was careful while digging down because I didn’t want to disturb any roots. When you dig out the basin be sure to make it at least as wide as the branches so that it can collect any water dripping off the leaves. I wasn’t super aggressive with the digging out of the basin because I was worried about the roots, so hopefully it’s dug down enough. I’m a beginner myself, so I can’t wait to see how this works. I gave it a test run with the hose and it held dramatically more water than the berm ever did. I’ll have to do this with the rest of plants in the yard.

See! That was easy! Just these two ideas give you a good start at using the rainwater as a resource and reducing your usage of tap water to water your plants. To get more in depth with water harvesting pick up the book Rainwater Harvesting for Drylands by Brad Lancaster. He lives in Tucson Arizona and has done amazing things with his yard and neighborhood all without irrigating with tap water. Check out his website for some great before and after pictures of his yard [here]. You can also attend one of his lectures or classes he teaches on rainwater harvesting to get some hands on experience. A list of his upcomming events can be found on his website as well. [harvestingrainwater.com]