Nothing makes Brad Lancaster happier than a monsoon downpour.

The tall 58-year-old jumped like a kid in the puddles on the sidewalk one recent August afternoon after a half inch (1.3 centimeters) of rain suddenly fell in Tucson, Arizona, during an especially dry summer.

“Sweet!” Lancaster exclaimed, beaming when he saw how the water pooled in a basin he had dug earlier in dirt planted with native vegetation along the public walkway.

“It’s really important that you are ready to plant the rain when it comes, even if it is a small amount,” he said, referring to a simple type of rainwater harvesting that involves digging a hole to allow rainwater to sink underground and be held like a sponge. “The key is to collect every drop of it.”

In the U.S. Southwest and beyond, home gardeners and landscapers are increasingly using collected rainwater to nourish their rose bushes and cactus gardens amid worsening drought and rising temperatures fueled by global warming.

Lancaster and other rainwater harvesting specialists say home gardeners anywhere can benefit from collecting raindrops and runoff from buildings and other surfaces to irrigate plants, even in wetter regions where the practice is less common.

Rainwater collecting is widespread in many of Earth’s driest regions. In Australia, it’s often used for drinking water, bathing and flushing toilets. And in Africa — where Lancaster said he learned more about the practice — it helps communities survive.

Some of the heaviest rainfalls in Arizona and other parts of the U.S. Southwest occur in the summer, during the annual North American monsoon season.

As much as two-thirds of residential water in the desert city is used outdoors, said Adriana Zuniga, an associate research professor in environmental policy programs at the University of Arizona.

In the case of Tucson, the city water department offers rebates of up to $2,000 for residential rain collection systems. It works with the local nonprofit Watershed Management Group to provide free 2½-hour classes residents must take to design a collection system that qualifies for a rebate.

One class anyone can attend virtually is the Essential Rain Water Course, offered for free on YouTube. It is co-hosted by water harvesting authority Peter Coombes, an honorary professor at the Australian National University and managing director of the independent think tank Urban Water Cycle Solutions, and Michelle Avis, co-founder of the Canadian organization Verge Permaculture.

Many proponents of collecting precipitation say the most authoritative book on the subject is Lancaster’s “Rainwater Harvesting for Drylands and Beyond,” along with a second volume published later. Lancaster also offers free resources to the public on his website.