Street-side basin ready to plant the monsoon rain!

If you've walked your dog down our street in the past few months, you may have wondered what that guy in the sweaty hat was doing digging a ditch in 114 degree weather. Well, I'll tell ya.  We are getting ready for the coming monsoons by installing a passive rainwater harvesting system to "plant the rain." The basins will sink the water from our roof and yard into the ground to irrigate the desert trees in our edible forest. The idea is to keep as much rainwater as possible from flowing onto the street and evaporating. The street side basin (above) is the last line of defense, so it is the deepest. If it works as planned, the street will be lined with a lush stand of moringa and wolfberry bushes.

This process has taken some time, planning, and plenty of sweat equity (especially on Dan's part.) Dan learned how to install passive rainwater systems by participating in Watershed Management Group's co-op workshops. At the workshops, co-op members get detailed instruction while working on passive (basins and berms) or active (cisterns) water harvesting or greywater systems. After volunteering for 16 hours, you can host a workshop in your own yard. If you have the money, I would highly recommend it. But to save money on the initial design consultation and co-op supervisor's fees, Dan decided to do the work himself. What a man!

*note: I think everyone should be able to afford to install waterharvesting features in their yard.  Apparently Watershed Management Group agrees. They've now offer a rainwater harvesting grant and loan program.  They also offer the free classes required to qualify for Tucson Water's rebate program. If you need inspiration, check out WSM's free living lab tour. It's fun!

Dan started by digging out gravel interspersed with (the bane of our existence) bermuda grass. That is one reason that this catchment basin is so deep. Some (sane) people would hire someone to excavate it with a backhoe. I would definitely recommend that if you have the money.

After Dan dug out the first layer of weeds, he had to remove a layer of plastic. Just under the plastic he found roots forming an elaborate design.

I was responsible for getting the weeds along the sidewalk. But I soon found that they were actually growing UNDER the sidewalk! Man! Those weeds are fierce! I used the side of the sidewalk as leverage to pry out the roots with my trowel (bending the trowel in the process!)

I got out as much of the roots out as possible. But the next day the grass under the sidewalk started growing again. Those weeds are invincible! They will be here with the cockroaches when we are long gone!  

I read somewhere that if you spray weeds with vinegar nothing would ever grow in that dirt again. Desperate times call for desperate measures.  So I sprayed vinegar right on the roots under the sidewalk.  

Those friggen weeds were everywhere! Here is my son Josh attempting to separate the weeds from the gravel. 

We still have 3 piles in our driveway: gravel, clay soil & palo verde mulch. (Four if you count the WEEDS! Argh!) We got free organic palo verde mulch from Romero Tree service.  They are happy to drop by the chipped remains of the tree they just pruned in your neighborhood! The only thing about our palo verde mulch is that there were still seed pods in the branches when they pruned it. A few of them actually sprouted, but I caught them while they were still small and easy to pull.

After removing all the gravel and grass, Dan started shaping the basins. He left truck-tire-shaped mounds to plant the trees and bush in. He made sure the floor of the basin was smooth - so there would be no puddling.

Before planting, we did a percolation test. I filled each hole with water to make sure it would seep into the ground in a timely manner. 

We planted the little wolfberry bush we got at Desert Survivors in one of the holes. Dan replanted some desert grass from our yard into the catchment basin. (No! Not bermuda grass!) The roots of the native grass create a sponge to keep the water in the ground. 

We mixed some sand we got from a nearby wash with the clay soil and put it in the bottom of the hole. (Moringa seeds need good drainage.) Then Dan mixed the rest of the soil mixture with some organic potting soil and filled up the hole. 

I planted 3 moringa seeds in each mound (about 1/2 inch deep) and watered them!

Dan worked by porch-light, then moon-light shoveling palo verde mulch into the basin. 

He was at it again the next day...

The mulch is so important to keep in the moisture - especially in the desert!  

Dan tamping sides of basin to make sure they don't wash away.

I watered the seeds just enough to keep it moist without soaking it. 

 In one week the moringa seeds actually spouted! Yeah! 

Then I deep watered the moringa and the hackberry bush every other day. 

I was worried about them in the 112 degree weather, so I put up some shade netting.

It also seems to help to water late at night. 

They are looking good. Growing new leaves! 

Ready for the rain! 

Finally got my catchment basin!

I don't know if it was getting the little cactus (hidden between the rocks), planting the first trees of our future edible forest, or posting Watershed Management Group's sign that did it. But Dan finally dug a shallow catchment basin to direct rainwater from the roof away from the house and to irrigate a patch of amaranth.

For some time we have been meaning to dig up the gravel and plastic that was keeping the rain from sinking in to the ground. Bermuda grass was already coming up where the aging plastic was cracking anyway.  We recently took out the bricks that were trapping the water next to the foundation of the house. Then we scythed the dried grass and piled it in the back for mulch.

         

This all started with observing the rain and watching where the water flowed or puddled (as they suggested at WMG). Using what he learned, Dan developed a plan that included an edible food forest, and a striking (and edible) burgundy amaranth patch. It would all be irrigated with rainwater redirected with berms and shallow basins. But digging up all that gravel was a little daunting, so Dan decided to do it one manageable section at a time.

First, he shoveled up a layer of gravel...

See how he dug it out in the shape of the basin he wanted. 

Pooh blinded by Dan's farmer's tan.

Wow! Must be at least 13 wheel barrels full of gravel there! 

Then Dan pulled the plastic up. He used his handy-dandy knife to cut along the line where he wanted the basin to go.

Oh, my gosh! Look at that clay and those grass roots! 

We thought nothing could grow under all that plastic and gravel! 

It took some real manpower to break all that up with the pickax. He had to go over it twice to get out all the roots.

When he got done, he could see that the ground was sloping (uneven towards the house). So he had to use the dirt he had broken up to build up a little trail. Then he had to go another round with the pickax. (Dan was careful to avoid the sewer line.)

"Boy, I wish I had that tamper for the trail." 

Finally Dan put down some of that dried Bermuda grass as mulch to keep the moisture in if it rained. (I know, I know. It sounds crazy but we've discovered that this locally abundant grass makes great mulch. It keeps the moisture in our veggie garden and in our baby trees.) See how well the little mesquite is doing with the grass mulch (below)? And no new grass has come in.

Finally got my catchment basin! (Thanks, baby!) Looking forward to planting amaranth in it!

Desert Landscaping: Going Native for Tucson's Rivers

Desert Landscaping: Going Native for Tucson's Rivers

There are some things that just drive me crazy! Like...why are there still patches of lawn in the Tucson desert? And those little rocks that get caught in your sandals – gravel!  I understand why people put gravel in their yards.  It conserves water, sure.  I don’t want to spend all weekend weeding either. But if you look at the sun cracked, gravel covered plastic we use to tame it, there are signs of life (weeds) breaking through. When some people think of the desert, they think of dirt. But our dirt is brimming with untamed life. 

When I first came to Tucson, I was amazed by all the green in our desert: our famous saguaros, prickly pears towering over roof tops, agaves with stalks resembling giant asparagus, and cholla cactuses lining the horizon like furry puppies glowing in the afternoon sun.  (Don’t try petting them though!) Twisted and gnarled Mesquite and Paloverde trees grow amok. This time of year wild flowers speckle the ground. The desert hums with bees pollinating brilliant cactus blooms. Our tough desert plants are adept at storing water for the long dry spells.

There are seasons when our desert has an overabundance of water. In the spring, icy water bounds down the Catalina Mountains into rushing rivers and streams. During Monsoon season, our washes rage and overflow. Not enough of this water sinks into our aquifer, because the caliche ground has turned hard from inconsistent rain. Instead our precious rain water is collected in city streets to be polluted with automobile oil. Lack of foresight and understanding have left us with no infrastructure to retain the water for our daily use. Miles and miles of cement aqueducts bring us water from the Colorado River. But we are beginning to see how vulnerable that supply is as poisonous tailings from long abandoned mines leak into Colorado’s rivers reaching as far as our own Lake Powell.

It wasn’t always like that. Tucson is one of the oldest settlements in the country.  Native Americans and Mexicans settled here for the abundant Santa Cruz river water. The Hohokam, expert desert farmers, created an elaborate irrigation system connected to the river. They captured rainwater with rock dams and storage tanks. The Tohono O'odham crafted earthen dams and brush weirs to divert water from washes to crops. There was a riparian habitat with abundant trees and animals. It wasn’t that long ago that our rivers and streams flowed year around. Old time Tucsonans still reminisce about playing in the river as children.

This was before bad management, over-pumping and drought depleted our ground water and turned those rivers into dry river beds. It was before cement and gravel covered the earth. 

Hope is budding around the desert like native wild flowers. Nestled in nearby neighborhoods are shady desert oases boasting colorful native flora and fauna.  Some are nourished with rainwater runoff from roofs or gray water from washing machines.  Water is diverted into the yards using berms and rocks to direct the flow to catchment basins where water soaks into the ground to nourish plants.

Tucson’s own Watershed Management Group is inspiring local homeowners and businesses to develop more sustainable landscaping. All this might seem overwhelming, but the WMG is here to help. They offer free classes on rainwater and greywater harvesting. You can learn more by taking their field studies courses. You can get started on creating your own desert oasis by joining their coop and working on other people’s yards. When you accumulate 19 hours, the volunteers will work on your yard for free (not including the cost of materials and consultation/supervisor.) Dan and I have started the process by taking classes and joining WMG's coop so we can transform our own yard using rainwater and greywater harvesting.

 Organic mulch and native grass in catchment basin allow water to seep into the ground.

One of the most incredible things we learned in Watershed Management Group’s classes is that we can all play a part in refurbishing our ground water so the Sabino and Tanque Verde Creeks will flow into the Santa Cruz River once again!

There are signs of positive change throughout the city. Tucson Water offers rebates for homeowners to install rainwater harvesting and graywater systems. The city is taking baby steps towards better water management. While there are still patches of grass by the Old Courthouse, there are also curb cuts to water native trees outside of the new County Public Service Center.  

emitters watering boulders

If we dig up all that boring gravel and enhance our rustic desert landscape with rainwater harvesting, we can play a part in replenishing Tucson’s groundwater so we can enjoy flowing rivers surrounded by flourishing Cottonwood and Willow trees.

UPDATE SEPT. 1, 2019: I am so excited about the City's Proposed Stormwater Management Program. Installing more Green Stormwater Infrastructure is one of the most impactful actions we can take to make Tucson water independent and secure in the future. As a citizen advocate, I have attended G.I. planning meetings at the Pima Department of Environmental Quality. I'm so impressed by the incredible the work that the city and county are doing to implement Green Stormwater infrastructure using guidelines by Watershed Management Group. To really be sustainable, we need these systems to be built all over town and to be maintained.

UPDATE MAY 1, 2020: Green Stormwater Infrastructure fee was included on utility service statements for residents and businesses within the City of Tucson to pay for maintenence of GSI.

UPDATE 2021: The City hired Blue Baldwin as Tucson Water's green stormwater infrastructure program manager. In November, Dan and I participated in a training to monitor GSI installations with city and county employees. In December, we also attended GSI maintenance training for landscapers and maintenance people working on the city's GSI features.