Lessons from Snow in our Urban Desert

 

I woke up to this view from my front door. Snow in Tucson!  This is the second time we have had snow this winter! This is the epitome of what Katherine Hayhoe termed "Global Weirding!" Maybe I'm exaggerating a bit. But it is weird. It is rare for it to snow in our desert town.  

I like to fancy myself a "citizen scientist" taking pictures to investigate what is happening in our garden and desert food forest. So out I went this morning with my cellphone to take pics of the snow. Here are the lessons I learned. 

The snow on the gravel or bare dirt has already melted. But where we have native plants (that some people call "weeds") or organic mulch in the catchment basin, the snow was still on the ground. I noticed that there was no snow left where our neighbors have gravel or just plain dirt in their yards. That demonstrates just how much heat gravel holds. But I already knew that from going barefoot when working on my yard in June. I walk on the horse purslane mulch to keep my feet from burning. 

I found a similar development in the easement behind our house. The snow is sticking to the desert mustard on the ground beside our garden. Notice that the snow isn't sticking to the ground in the garden perhaps because the palo verde branches that shelter it from the summer sun also shelter it from the cold. Note that there are no "weeds" in the garden. 

See the snow on the bunch grass in our jujube basin? As the snow melts it is another source of water for the plants and trees in our basins. 

Our native desert trees and bushes have adapted to the occasional freeze and snow storms. In fact, the hackberry in the mesquite guild (below) and our wolfberry in the right-of-way basin seem to be thriving in the snow. The organic mulch helps.  

Then I investigated what was happening in the backyard. The snow was already melting into the greywater basin supplying water for the heritage fruit trees there.

As anyone who has a cistern (rain tank) knows, we get lots of rain off of the roof.  Now our cisterns are overflowing from the snow melting off of our roof and the neighbors' roof. 

snow on our neighbors' roof

snow melting into the cistern

The cistern overflows into the garden...Sheltered by the branches of the palo verde, the chard is doing fine. 

Reminds me of how the snow melts on the Catalinas, rushing into our desert streams to nourish the surrounding trees and riparian habitat. 

view of the top of our watershed - the snowcapped Catalina Mountains

Here's what I learned from my little citizen science project this morning:

I learned that ground covered with gravel retains more heat so the snow melts. But without a catchment  basin to gather that water for a nearby tree, the water is often wasted. (Though the water can sink in under the gravel to water a nearby plant if there is no plastic preventing it.)  In our yard, the native grasses and organic mulch allowed the water to slowly melt into the catchment basin to the benefit of our native trees and bushes. I observed how the snow in our greywater basin melted into the basin to water our heritage fruit trees and how the snow on the roof melted into our cisterns filling them up to use on our garden and landscaping.

Who knew we had a "snow water harvesting" system?! In the desert! How great is that!? 

For the Love of Tucson: Creating a Desert Oasis to Combat Climate Change

When I first moved to Tucson, it rained most every day during monsoon season. I remember waiting for it to cool off in the evening so we could take the little ones to the pool. Inevitably we would wait in the car as a storm swept by. Then we would enjoy the most luminous sunsets as we swam - storm clouds catching the brilliant hues of the setting sun. That was the beginning of my love affair with this stunning desert. But it wasn’t until I witnessed the ravages of record heat and sparse rain on our own little monsoon garden that my heart became totally invested in fighting the effects of climate change on our desert town.

I've often pondered how climate change would affect Tucson.  Nobody knows exactly.  But, from what I've learned, climate change often seems to intensify the extreme weather of a particular area. In that case, Tucson would continue to experience rising temperatures, prolonged droughts and more severe floods. That means even more flood damage as storms further erode the banks of hard, dried river beds.

The desert will eventually return to its natural state with or without us. But if we don't stop savaging the earth for profit, Tucson could become a stark, barren desert. If we don't change our ways now, even our iconic saguaros won't be able to survive the scorching heat.

I sometimes wonder what will become of my little house after finally paying it off. If temperatures continue to rise, would my boys still want to live here? Would they even be able to sell the house if they decided to leave? That's one reason I'm dedicated to finding ways to lessen the impact of climate change on our town or at least find ways to live here comfortably.

Anyone who is paying attention knows we need to reduce our dependency on fossil fuels and curb our wasteful consumer lifestyle if we want to stave off climate change. But for Tucson to be more resilient, we need to learn to responsibly use the resources the desert has to offer: the power of the sun, native flora and fauna, and our seasonal rainwater.

We can start by implementing solar energy* to keep our air-conditioners running and planting native shade trees to cool our neighborhoods. But to be really sustainable we need to start living in harmony with the desert. No, I'm not talking about living off the land like the Hohokam before us. I'm not talking about giving up all of our modern conveniences. (Most of them can be adapted or retrofitted to be more environmentally sound.) I'm talking about restoring as much of the desert habitat as possible in an urban environment. I'm envisioning our neighborhoods as desert oases with edible forests of native plants and desert rain gardens with drought tolerant heritage crops. You've probably seen some lush desert landscaping or cool community gardens popping up around town. That's what inspired Dan and I to plant our own edible forest irrigated with rainwater and greywater and to start experimenting with drought tolerant crops. We are working towards food security.

How do we transition Tucson into an urban desert oasis? The first step is embracing the nature of the desert we inhabit. Stop trying to force it into something it's not. Stop bulldozing it and paving it over for perpetual development. Shut off the sprinklers that water those little patches of grass in front of businesses. Sorry, manicured lawns don't belong in the desert - native plants do. We need to rethink our perception of tidy xeriscape landscaping and stop suffocating our native vegetation with plastic and mounds of gravel. Why on earth are we raking up all that great organic matter that could be nourishing our soil and allowing the rainwater to sink in? And all those weeds we "Roundup" can help prevent erosion.

Noooo!

One of the biggest concerns of living in the desert is having a reliable source of water.  Right now Tucson depends on CAP water. A whole coal-powered generating plant was built to run the pumps that push our water 336 miles uphill from the Colorado River. Unfortunately, that source isn't sustainable. As droughts continue, there will be more competition for that diminishing water supply. The river supplies over 40 million people in Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming and Mexico as well as a $5 billion-a-year agricultural industry.

The good news is that there is enough annual rainfall to supply every Tucsonan's water needs - if we harvest the storm water. While the city and county work on their own green infrastructure improvements, we can incorporate rainwater harvesting features that keep the water in our yards to irrigate our native landscapes, edible forests and drought tolerant gardens.

Diverting roof water to wood chip mulch covered catchment basins conserves water which helps to restore our aquifers. Those near a river or wash can even help infiltrate water to the aquifer. If you wanna see how it's done, you can tour Watershed Management Group's Living Lab and Learning Center. Using a combination of cisterns and earthworks, WMG harvests enough rainwater (during a regular monsoon season) to meet all of their needs - including irrigating some fruit trees! But more important are their efforts to restore Tucson's aquifers and get our rivers flowing again.

Underground cistern at WMG's living lab

By returning our yards to a more natural state that allows rainwater to sink in, our hope is that it will replenish the Tucson basin and get the rivers flowing year around.

But here is an even greater vision!

 

If we could get everyone on board, we might even be able restore the riparian habitats by the rivers. We could transition to green infrastructure throughout the city. We could all use earthworks to sink in more of the storm water in our yards, schools, churches, business properties, and empty lots. That would slow down the rush of water before it gets to the rivers and washes. That native vegetation would act as a sponge allowing flood waters to sink in! There would be less flood damage. (Extreme weather costs Tucson and Pima Country $9,449,667 a year.)

Restoring the riparian habitat would attract more birds and other wildlife to Tucson. Arizona is already a bird lovers' paradise with ecotourism contributing to our $21.2 billion tourist industry. Imagine Tucson becoming the hub of ecotourism!

     
What is your vision for Tucson?  Would you like to ride your bike along a flowing river surrounded by twisty mesquite? Pick a fig from the orchard in the park? Enjoy the sight of  hummingbirds, butterflies and other pollinators fluttering around desert shrubs in a traffic median? Snack on some yummy edible weeds without worrying about pesticides? Stop by a neighborhood garden stand for some freshly harvested salad fixin's? Wouldn't it be cool if a local farmer grew drought tolerant heritage white wheat and amaranth by the Santa Cruz river to be milled right here in Tucson and baked into healthy bread in Tucson's own native grains bakery?

That's me holding a bag of freshly milled mesquite flour.

 I have a dream. I believe Tucson can thrive in the future if we reduce our dependency on fossil fuels, cut down on waste, restore our desert flora and fauna, and use the desert's resources responsibly.  Instead of polluting our water by mining coal, we can use one of the desert's most abundant resources - the sun! Why not power our vehicles, homes and businesses with solar? We can retrofit our older houses and business buildings to conserve energy and water. We can have neighborhood micro food parks with safe bike and walking paths. We can make Tucson THE ecotourism destination by attracting more birds and wildlife to our urban desert. And all those desert trees sequester carbon!

Brad Lancaster shows how a curb cut lets in street water to irrigate mesquite trees.

We already have a great community working to make Tucson more sustainable: Sustainable Tucson, Feeding Tucson, Community Water Coalition, Sonora Environmental Research Institute, Sonoran Institute, Watershed Management Group, Tucson Water, the 2030 District, Local First, Zero Waste Tucson, UA Compost Cats,  Desert Harvesters, Iskashitaa Refugee Network, Arizona Master Naturalists, The Sierra Club, Tucson Audubon Society, Pima County Master Gardeners, Mission Garden, Community Gardens of Tucson, Trees for Tucson, Native Seeds/SEARCH, the Pima County Seed Library, Living Streets Alliance, the U of A, the Desert Museum, and the Community Food Bank's Community Gardens. Several schools like Manzo Elementary and Changemaker High have gardens.

The Pima County Department of Environmental Quality has a manual on green infrastructure. The City of Tucson and Pima County have pledged to fight climate change and even implemented a Green Infrastructure fee. Check out the Mayor's Million Tree Program. 

Let's work together for a sustainable future for Tucson!

MORE ABOUT GREEN INFRASTRUCTURE IN TUCSON

https://www.sustainablelivingtucson.com/2019/09/support-tucsons-green-stormwater.html

MORE THINGS YOU CAN DO...

What Kind of Climate Champion Are You? 

Exploring food forests in Tucson

Brad Lancaster's Documentary:

Water Harvester: An Invitation to Abundance - Arizona Public Media