rain


We just had a big rain in Joshua Tree–over an inch in a short period of time. After a rain like that, within hours, tiny plants start sprouting in what had been bare sand for a year. It may be because I haven’t paid close enough attention, or it may be because different seeds sprout after different kinds of rain events, but these plants are unfamiliar to me. I don’t know what they are called or even if I’ve seen them before.

This is about 4″ tall, the biggest I’ve seen so far.

This grows really fast. It’s about a foot wide.

This is maybe 1.5 inches across and appeared late–maybe a week after the rain.

This is less than an inch tall. It first looked like a miniature succulent, then a miniature cactus. Something is eating them down to a nub at a quick pace. It was one of the first to appear: http://instagram.com/p/dxmcnNF6TW/

This makes a low ground cover over maybe 10 square feet. It’s maybe 3/4 of an inch tall.

This came up late, too. The big ones are about an inch tall so far.

I just noticed this one today. The ring is about 4″ across.

I don’t think this one is a mystery. We call it ragweed and it shoots up anywhere the ground has been disturbed, like roadsides and scraped lots. This plant was about a foot tall but I’ve seen many of them waist-high.

I work at the Monterey Business Center in Yucca Valley, California, which is about 250,000 square feet of flat roofs and cement parking lot. I’d been wondering what all that would look like in a rain event and on August 29, 2013 I found out.

Monterey Business Center arial from Google Maps

Monterey Business Center arial from Google Maps

Jackie is not as excited about the rain as I am.

Roof water pours onto the sidewalk and into the parking lot

The parking lots have channels to direct water to the street

Onto the street

Down the street

Off the end of the street

Into a gully. (The blue-topped pipe in the gully says “water” on it. I thought that was hilarious.)

Down the gully

Flash flood in Yucca Valley on Make A Gif

And through the desert

pkvKsi on Make A Gif, Animated Gifs

Until it hits the berm of a road

Until it breaks through onto the road

And starts to flow down the road

This is where it ran out of steam. The water puddled up here and then mostly evaporated, “To rain again on someone else, east of us,” as Buck from Transition JT says. If there had been more water, it would have poured down this road and into a slightly more intentional gully at the end of it:

It would eventually hit the big wash in front of those mountains in the distance and flow east to the dry lake bed that is just west of Copper Mountain, maybe 18 miles away. That’s the lowest point in our watershed.

dry lake

Copper Mountain, Sunfair lake bed in front.

[animated gifs made at MakeAGif]

I went to my first Transition Joshua Tree event, a rainharvesting workshop on April 28. It was fun and inspiring to meet with a good-sized group (maybe 20?) of neighbors interested in water sustainability in Joshua Tree. It was nice timing, too. Reanna and I just spent the previous day on the Desert-Wise Landscape Tour, looking at how local people are designing for low-water use.

The main topic was how to catch and store rainwater that falls on your roof. Our presenter, Buck, seemed to have quite a bit of experience installing gutters and catchment tanks, and thinking about water in the desert. He had a machine that made seamless gutters of any length out of strips of aluminum:

gutter maker

And showed us some tanks and filtration systems:

catchment tanks

One of the participants reported catching over 2,000 gallons of water in a four-minute “rain event” with one of these systems. While it is very dry here (less than a half inch in 2013 so far, I believe) it can rain really hard. In my 10 years in the rain country of the Pacific northwest, I never saw it rain half as hard as a big rain in Joshua Tree. So you can wait a long time for a rain event but you want a large storage capacity when it does.

We want to catch as much of the water as possible because we are using up our aquifer about 10 times as fast as it is replenishing. (If it is replenishing, that is–there seems to be some controversy about it.) Water that runs off of our roofs flows down washes to the dry lake in Sunfair, where it mostly evaporates, and eventually rains on someone else downwind of us. According to the conservation representative from the Joshua Basin Water District in attendance, we use 151 gallons per person per day and sustainable use is under 15. She talked a bit about two plans to replenish our aquifer using technology: One, under way right now, is piping in northern California water from the Hisperia aquaduct down into our aquifer. Another, under study, is diverting the Quail Springs wash from the surface (and the dry lake) underground. I’m not sure what that will look like–I picture a 600 foot hole in the middle of the wash, with caution tape around it–but at least it would be using our own water.

Living on less that 15 gallons of water a day looks to be tough. Here’s an essay by my sister-in-law, Maya, about going from 420 gallons per day to 50 gallons a day, with a toddler and while continuing to grow food. I’d like to visit each person who came to the workshop and see what systems result in what level of water usage. Because Reanna and I share a water main with my family, I don’t know how much we are currently using. I will figure it out and write a post about it.

I just visited my brother Ely in Glendale and the forecast was calling for rain in the next couple days. He was happy about that. They need the water. Glendale gets an average of 21.09 inches of rain a year (according to Wikipedia) and had only 16.95 inches in the last ten months (according to Weather Underground). Ely just emailed me that a meteorologist on the radio today said they’ve only gotten 5.15 inches so far this year, 9 inches below average).

But what is going to happen to that rain water? Almost all of it will fall on rooftops, sidewalks, parking lots and roads:

Glendale

For a case study, I looked at Ely’s neighbor’s roof. They have a gutter on the low side, which will catch most of the rain that falls on that roof:

photo (23)

photo (24)

The neighbor’s gutter dumps into a drain pipe that heads towards the street on Ely’s side of the wall, picking up the runoff from another roof along the way.

photo (25)

Back on the neighbor’s side of the wall, the pipe dumps on the ground.

photo (26)

The water runs along the wall, down onto Ely’s yard, and onto the sidewalk.

photo (27)

Down the sidewalk, into the street.

photo (28)

Down the street.

photo (29)

And into 50 feet of storm drains.

photo (31)

Verdugo Wash

The drain dumps into the Verdugo “wash,” a giant concrete culvert a few blocks away.

Los Angeles River

Which is a tributary of another, even bigger concrete culvert, the Los Angeles “river.”

(photo by Ron Reiring

Which dumps into the Pacific Ocean at Long Beach Harbor. (photo by Ron Reiring)

The system moves the water that lands on Glendale to the ocean quickly and efficiently. Meanwhile, they wash their cars and water their lawns with water pumped in from the distant Colorado River.

Here’s a totally different way of thinking about rainwater, from another, drier city that also relies on the Colorado River–Tucson, Arizona. Watch for the wow moment, starting around 1:20: