This Eco-Friendly Lawn in Arizona Mimics a Natural Stream Overflow

In Tucson, like many other desert cities, severe drought has led to tight restrictions on lawn irrigation (and rebates for installing rainwater harvesting and gray-water systems). But the region is not entirely without water; long periods of arid heat are punctuated by monsoon rains. Creating systems to take advantage of those sudden, fast, intense storms is key, says Andrew D’Arezzo, a landscape designer and eco-hydrology specialist at EcoSense, a local landscape design firm that focuses on water-wise solutions.

For Hadley Castaneda, the owner of a traditional adobe residence built in the 1930s in central Tucson, the challenge was to address those water issues in an attractive but low-maintenance sustainable garden that would suit its use as a vacation rental.

EcoSense devised a passive rainwater harvesting design using bio-gravel, "a proprietary mix that mimics a natural stream overflow," explains D’Arezzo. Water is able to infiltrate the soil rather than pooling or flooding, "so the yard can hold every inch of rainfall on the property safely." D’Arezzo and his team also used traditional clay vessels called ollas, placed underground with their lids just peeking out, which allow water to percolate slowly through the terra-cotta and directly into the root zone with almost no evaporative loss.