Tucson City Councilman Rodney Glassman made his pitch for rainwater and gray water harvesting requirements in new construction to the Marana Town Council last week.
"Rain is the most pure source of water we receive," the Ward 2 councilman told the council and staff, "yet historically, we've treated it as a waste product."
Tucson has passed an ordinance requiring rainwater and gray water harvesting capabilities be built into new residential and commercial construction. Oro Valley has done much the same, and Glassman shared copies of the Tucson ordinance with Marana officials during his presentation. "As a municipality, you don't have to start from scratch," he said.
Rainwater is plentiful, Glassman said. Tucson's annual water demand is 147,000 acre feet of water per year. In the form of rain, 185,600 acre feet of water falls on the city annually.
"It's free," he said. "It falls where you need it." He urged communities to "harvest it, and stop spending money getting rid of it. It's a very, very cost-effective alternative to other costly sources of water."
"Microbasins," swales, infiltration basis, French drains, curb cut-outs and porous pavements are among the most efficient ways communities can capture rain water for landscape and other uses. Tanks and cisterns are more costly than on-the-ground harvesting techniques.
Harvesting of gray water – from sinks, washing machines, and showers – can be accomplished by requiring "stub outs" on new residential construction. "There is no retrofitting" of existing properties, Glassman said.
The Tucson ordinance requires new commercial properties to meet 50 percent of their landscape water demands through water harvesting. He urged governments to "keep ordinances simple and flexible, so it's adaptable to future technologies.
"We can develop Arizona as the go-to source for water harvesting," Glassman said, arguing it's good for business and job creation.
"We're at the bottom of the Central Arizona Project, and the Colorado River," Glassman observed. Given drought and other factors, "it's only going to get worse for our cities and towns," he said