Tuesday, March 02, 2010

Nourish your little piece of the desert with rainwater harvesting

Five years ago I bought a 740-square-foot dump in midtown Tucson with a large yard full of goat head burrs and Bermuda Grass. Maybe I was a victim of too many episodes of HGTV design shows, but my plan was to transform this territorial adobe into a cute little home with a yard full of desert-friendly plants, fruit trees, and a vegetable garden-- all irrigated with rain water and grey water.

In 2007, the first phase of my remodel was to add a master bedroom suite, utility room, and covered patio-- increasing the house to a modest 1240 square feet. The second phase-- which began in 2007 and is continuing-- was to capture rain water and transform the wasteland that was my yard into a garden retreat. (The attached slide show details this process in photos.)

Before I started the process, I attended a rainwater harvesting workshop at Stone Curves Co-housing. I spent two weekends digging trenches and installing a cistern with the help of local rainwater harvesting guru Brad Lancaster, landscapers from Technicians for Sustainability, and other volunteers.

Armed with new how-to knowledge, the first step was to design my addition to divert rain water to a future cistern. The entire roof of my home and the addition was sloped toward one scupper on the west side of the house. The patio roof was slanted toward the trees on the east side of the yard.

The second phase was digging-- lots of digging. I dug large tree wells around three major trees, a pomegrante bush, and a desert hackberry in my backyard. I even dug in the rain, which is a curiously refreshing exercise in the summer. It also gives you a very clear idea of where the water is and where it goes once you start digging.

The third phase was to hire a contractor to install gutters, downspouts, and drainage pipe on the patio. Initially, three of the trees were watered with grey water from a washer in a shed in the back, and the other two were watered with runoff from the patio roof.

The fourth phase in January 2010 was to finally install a 900+ gallon cistern, dig a cistern overflow ditch, and add more gutters on my out buildings. With all of the rain that we have this winter, it has been very exciting to watch the cistern fill up repeatedly and overflow into the ditch, carrying the water to other trees. It's also been rewarding to plant bedding flowers and know that I am not wasting city water when I care for them.

The final phase will be to attach the cistern to my existing drip irrigation system and to plant fruit trees this spring and maybe a garden after the summer heat.

Using rainwater and grey water helps our desert environment by allowing you to use less ground water, thus reducing your environmental footprint. If you want to learn more about the process, I highly recommend that you read Lancaster's book, attend a workshop, and buy a good shovel.