Water in the Desert

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Photo courtesy MOTHER EARTH NEWS editors
Valerie and John Titan, at left, in front of their home, which is in the upper watershed of the San Pedro River.

At our off-the-grid Arizona home, we conserve water to
help protect this fragile ecosystem.

When we moved from rainy Portland, Ore., to Cochise County,
Ariz., in 1999 to build a 1,200-square-foot solar, straw
bale, completely off-the-grid house, we went one step
further than most folks and decided it would be easier on
the local environment if we didn’t drill a well. We live in
the Chihuahuan desert, an area that only gets an average 11
inches of rain per year (for the past few years the average
has been closer to 7 inches!), so rather than depend on an
already overtaxed aquifer for our household water needs, we
decided to install a rainwater harvesting system. We
conserve water carefully, but we live quite comfortably
with this limited supply.

Protecting the natural beauty and rich wildlife habitat of
the nearby San Pedro River, which is directly dependent on
water from the aquifer, is our motivation for saving water.
We live in the upper San Pedro River watershed, near one of
the few cottonwood-willow riparian corridors in the
Southwest. The river is familiar to many birders and
scientists, and National Geographic featured an article on
it in April 2000, written by the well-known author and
Tucson, Ariz., resident Barbara Kingsolver. More than 300
species of birds visit this corridor during their seasonal
migrations.

Sadly, the San Pedro is going the route of many other
Arizona rivers: It may be in the early stages of drying up.
Perhaps foretelling disaster, the growing number of people
who reside in the upper San Pedro watershed use more than
double the amount of water that is recharged into the
aquifer each year. As the aquifer’s level drops,
increasingly larger portions of the river are disappearing,
leaving dry gravel beds where Sonoran mud turtles and Gila
topminnows once swam.

Going Off-the-Grid

With money we saved while living in Oregon, we built our
straw bale house, doing almost all of the construction
ourselves, with some help from family and friends. We lived
in a small camp trailer on the property for more than a
year while building. During most of that period, we were
able to take some time off from work; then as money ran
low, we transitioned to part-time and then full-time jobs.
Right now, both of us work as counselors for the county
health department.

Our house was built as cheaply as possible; we scavenged
windows and doors, cabinets and tile by asking people who
were remodeling their homes if we could have their used
materials. Our completed home is both cozy and beautiful.
Because we did not contract out any of the work (including
the concrete foundations and floors!), we were able to
build without a mortgage. Not having to make monthly
payments on a house is liberating, but what provides even
more satisfaction is knowing that we are actively making
choices to minimize our impact on our very sensitive
environment.

Our solar-powered home runs on a very simple photovoltaic
(PV) system that we installed ourselves. The entire cost of
the equipment — array, battery bank, charge controller and
a 1,300-watt inverter (designed for motor homes) amounted
to less than $3,000. We are able to run our television and
VCR, stereo, microwave, toaster, vacuum, water pumps, fans
for cooling and all our lighting, as well as our power
tools. Our only inconvenience so far is incredibly minor:
We cannot run the microwave and the toaster at the same
time.

Our refrigerator and stove run on propane. We use 7-gallon
propane bottles and refill them as needed at the local gas
station, 15 miles away. We talk of having a 200-gallon tank
installed and serviced by the local propane company, but
the inconvenience of filling bottles hasn’t yet pushed us
to that expense. Most of the year, each 7-gallon bottle
lasts four to five weeks, and we have two. During the
winter, if we have to use the propane heater, a 7-gallon
tank may last only 3 weeks. But we rarely need to use the
heater because the winters are relatively mild and our
house has many passive-solar design features. Large
south-facing windows combined with the thermal properties
of our straw bale walls and sunlight-storing concrete
floors keep us toasty warm; we only need to heat with
propane when we get three cloudy days in a row during the
winter, which rarely happens here.

Collecting Rainwater

We put on the roof and began collecting water before we had
even finished the walls. We have about 1,200 square feet of
roof area, and even the most liberal estimates on water
catchment ascribe only 960 gallons per inch of rain for a
roof that size. Using the 11-inch rainfall average for our
region, we figure we potentially could collect 10,560
gallons in an average year, which is only a small fraction
of the nearly 150,000 gallons a typical North American
household uses.

We have only 6,000 gallons of storage capacity, but since
our region only receives rain during the summer and winter,
we are able to fill the tanks in the summer, use some water
in the fall, and then top the tanks off again in the
winter. The toughest time is between February and July when
the dry winds suck away every drop of moisture. Our stored
6,000 gallons has to last through this period.

We have a roof “washer” that we built ourselves, a device
that diverts the first 5 gallons of water that come off the
roof. This helps to keep the dust and any other materials
that may be on the roof out of our water storage tanks. We
also have a screened intake area to keep contaminants out
of the water and a filtering system to further purify it.

The poly tanks used to store drinking water are expensive,
running about $1,000 for a 3,000-gallon tank, so we started
with just one and added the second tank later. At some
point we could add a third, but so far we haven’t found
that we need that much water.

Careful Conservation

Even with low-flow toilets, you’d be surprised how much
good, clean, drinking-quality water gets flushed each day
in this country. Our first conservation measure was to
install a composting toilet, which uses no water.
Composting our waste also is good for the soil, as we use
the mature compost around our trees. True, there is some
maintenance involved in a composting toilet, but ours has
required only minimal upkeep.

Any inconvenience to us pales in comparison to the
inconvenience to the Sonoran mud turtles who are no longer
able to migrate up and down the river. And to be perfectly
honest with you, there is something satisfying about being
responsible in this way for our own waste.

We also have perfected the art of showering. We had good
training, because before we installed plumbing, we had to
haul water by hand. During that time, we decided that the 5
gallons our solar shower could hold was more than
sufficient for two bathings. Taking short showers has
become ingrained, but just to keep us honest, we installed
a low-flow shower head with a stopping valve and a 6-gallon
hot water heater. If you wish to take a long shower at our
house, you have to be prepared to take it cold! Also, to
not waste any more water than necessary, we often keep a
bucket in the shower and dump the collected water on the
garden.

To wash dishes, we fill the sink only a few inches. Rather
than running water over the dishes to remove food
particles, we first wipe the dishes down, separating out
the food residues for composting. That keeps those few
inches of water clean far longer, and we can wash a larger
load with less water.

All our drains (except the wash side of the kitchen sink,
which is by law required to go to the septic tank) go to
trees we have planted, so the water gets reused
immediately. We have a small, 12-by-4-foot kitchen garden,
which we occasionally have to stop watering, but only
during periods of extreme drought. Then, we have lost some
plants, but not all. Our landscaping plants have fared
particularly well because we specifically chose
drought-tolerant species — most of them native to the area —
including palo verde trees, mesquites and desert willows.
When we started rainwater harvesting, we were using
rainwater for drinking and cooking, but more recently, we
switched to store-bought water for drinking.

The reason was that our roofing material — uncoated
galvanized metal — is no longer considered the safest
material to collect drinking water because when it begins
to corrode, the metal could introduce contaminants into our
water supply. So we decided to be cautious with our
drinking water; however, we still use harvested rainwater
for most of our cooking.

The one luxury we have forgone thus far has been a washing
machine; we take our laundry to a laundromat. Right now,
this adds to our consumption of water from the aquifer, but
we hope to soon buy a super-efficient machine for home. We
should have enough water, given the average rainfall, but
the droughts of recent years have left us unsure.

Last year was an especially dry year. We began the annual
February-to-July drought with only 2,500 gallons in the
tanks, and were down to only a few hundred gallons before
the tanks began to refill during the rainy season.

But, we survived just fine with even that small amount of
water, and our rationing was by no means unreasonable or
uncomfortable. We still took daily showers and were able to
give some water to the plants.

This tells us that with the return of normal rainfall
patterns, we should be able to wash our laundry at home
provided we buy a water-efficient washer. Some use as
little as 18 gallons per load while most machines on the
market use 40 to 50 gallons!

All in all, we have carved a satisfying life out of the
harsh environment that is the Chihuahuan desert. We have
created a lifestyle where we can live simply and cheaply
without sacrificing comfort. This life is not for everyone,
perhaps, but for us, it is the realization of a dream that
we built slowly over the years. We hope those of you who
share such dreams may be fortunate enough to realize them
as we have.