The Canal that Accidentally Grew a Forest in the Arizona Desert

[Music] so here we are west of phoenix in the desert at the central arizona project canal this canal brings 500 billion gallons of water every year from the colorado river all the way to the phoenix basin eighty percent of the population of arizona basically gets their water from this canal now the colorado river used to flow all the way to the ocean through mexico but now the colorado river doesn't even make it to the ocean because so much water is pulled out by the various states that use it arizona being a large user this canal travels 336 miles and it's got to be pumped up over mountain ranges in order for it to move by gravity it was started in 1973 the year i was born and it was completed in 1993. so this is about 30 years of this canal being here and basically this is the lifeblood of the majority of the population of arizona of that 500 billion gallons of water about five million gallons evaporates each year there's a lake just a little ways down from here called lake pleasant a lot of this water is actually pumped into phil lake pleasant and about 16 million gallons evaporates from the surface area of lake pleasant each year and then over 100 billion gallons each year are actually pumped back into the ground in order to store it in the aquifer to be pumped out for reserves so it's this crazy huge piece of infrastructure as far as water marvels arizona would not be the place that it was today the green lawns and golf courses and development and the green agriculture where they're growing alfalfa and cotton and you see the expansive freeways and urban sprawl of phoenix with its green lawns and green grasses and swimming pools and all of this is made possible because of this basically the redirection of this massive amount of the colorado river's water into the urban megalopolis here of the phoenix valley and also the city of tucson is at the end of this 336 mile canal so that's mind-blowing just by itself but the ironic part of this whole thing is that this canal is placed in a way in this landscape so it actually functions as a water harvesting structure you see we've got water coming down these hills right runoff when you get big monsoon rains and flash floods coming down and this canal is built up on a berm right this canal is built up so the runoff doesn't come and wash things into this water so it's built up but it serves as this giant berm that intercepts this flowing water and creates these big forests of native vegetation right it's like a giant swale inadvertently placed in the landscape that acts as this massive water harvesting structure so in permaculture we talk a lot about how oh you know the perfect feature for the desert landscape right is to put these swales perpendicular to the water flow so when the rains come the rain pools up against these berms and soaks in in order to grow trees so here inadvertently this whole canal system is serving as a giant berm in the landscape where all the water is rushing down these mountainsides here into these washes and drainages and you know flowing down during rains and then it's all pooling up on the upside of this canal here and creating this native forest bill mollison came to the sonoran desert back in the early 80s to show these big swales that were dug by the civilian conservation corps and showed how if you just put these big swells in the landscape and leave them then a forest will grow and here we are between 30 and 50 years after the construction this canal and we have this whole long network of these forests created by this inadvertent swale placed in the desert landscape so here i am underneath the canopy of this mesquite tree right here and this is down here in the basin on the uphill side of the central arizona project canal and it's late november right now so the leaves are not on the trees here but in the summertime this is going to be a dark shady place with lots of stored moisture in the soil and fertility from all of the leaves dropping from these trees so this is an excellent oasis type microclimate that's been created by all of this water pulling up here in the desert places like this where you have diversity of species you've got tree canopy these are really important areas for the ecology to take respite from the open desert so you can see what this looks like in comparison here to the open exposed desert it's a completely different and sheltered ecosystem so in a way it's this massive piece of infrastructure that's evaporating all this water it's re you know it's it's very much not working on biological systems right this is a human concrete designed piece of infrastructure that is losing water it's not increasing biological systems biological diversity along the way but inadvertently accidentally it is creating this proof of the biological solutions to the water problems of the deserts harvesting the periodic runoff that comes in heavy rains so it's just really mind-blowing to think about and to think about all the diversity habitat the the groundwater that's actually being built by the water soaking in on the uphill slope of the central arizona project [Music] you

Channel: Andrew Millison

Views: 3,658,651

Keywords: rainwater harvesting, permaculture swale, greening the desert arizona, greening the desert, central arizona project, rainwater harvesting project, permaculture swale design, permaculture swales, permaculture swales on flat land, permaculture swales on contour, swales and berms permaculture, permaculture water harvesting through swales, desert permaculture, desert reforestation, arizona desert water, building swales permaculture, desert reforestation projects

Id: jf8usAesJvo

Length: 6min 53sec (413 seconds)

Published: Mon Nov 29 2021

Reddit Comments

[u/Mcdibbles]

Anyone interested in this should check out this channel's series on water in India. Very eye opening and vitally necessary as climate change reduces freshwater resources.

[u/MapsActually]

A similar thing happened when they dammed the Salt River to create Tempe Town Lake. Just upstream of the lake water pools in the river bed, which happens to be underneath a major freeway. Now there is a lush riparian zone in the shade of a freeway that historically was a mostly dry river bed. Accidental urban conservation.

[u/Local_Somewhere8154]

Andrew has one of the best youtube channels regarding permaculture. He's very knowledgeable and his videos are on a variety of different subjects and locations. I personally like the video where he visits Egypt.

[u/Nellasofdoriath]

Slowing a river in arid zones can cause increased evaporation. Care is required.

[u/maposa]

I watched it, I am so schocked that they take so much water and then there is no water in the river. That is not sustainable.

[u/App1eEater]

So what I'm getting from this video is that a bunch of people probably shouldn't live in a desert

[u/Happymuffn]

Imagine if we started doing it on purpose

[u/Riptide360]

Good video on natural water berms vs man made canals.

I wish the Western US water Canals had been built like the older European and East Coast Canals that used barges to move goods down river and barges with horses or trains to move them up river.

I hope they look at adding solar panel shade panels over the water canals to capture solar power and reduce water run evaporation.

[u/socradeeznuts514]

In a similar vein, this adorable documentary:

https://www.youtube.com/watch?v=PLyBZ1mdg2c

Leave it to beavers