A long-dormant natural feature of Tucson, Arizona's early years is on the verge of making a dramatic comeback.

The Santa Cruz River, presently little more than a dry scar of earth through the city's urban center, will soon begin flowing again for the first time in more than 70 years. The revitalization, called the Santa Cruz River Heritage Project, will come courtesy of recycled wastewater, with plans to create an initial stream 20 feet wide from as much as 3.5 million treated gallons per day.

"We're putting this water back to beneficial use. It's our water," Jeff Prevatt, deputy director of Pima County Wastewater Reclamation, told Arizona Public Media. "We want to keep it within our community because we live in a desert. We want to ensure sure every drop of water we pump out of the ground, we put it to maximum beneficial use."

Reawakening the past

The Santa Cruz River, complete with little waterfalls, as it appeared flowing through downtown Tucson in 1889. The Santa Cruz River, complete with little waterfalls, as it appeared flowing through downtown Tucson in 1889. (Photo: The University of Arizona Archives/Wikimedia Commons)

Like many rivers in the Southwest, the Santa Cruz fell victim to development and agriculture, with groundwater pumping decimating the water table to the point that no section has carried a natural water flow since the 1940s. Its loss not only wiped out the wildlife that used to flourish along its borders, but also one of the largest mesquite forests in the world.

"This town thrived and was built on the banks of that flowing river," Fletcher McCusker, chairman of the historic development organization Rio Nuevo, told NewsDeeply. "It's our own damn fault that it's not running, because we just overabused the river and the water table. To have a chance to restore it is a great idea. I'm a big fan, whether it's a trickle or bank-to-bank."

Ironically, the conservation measures put in place to correct past abuses will now also breathe new life back into the river. Over the past several decades, Tucson has invested heavily in wastewater reclamation facilities tied to a sprawling network of pipes snaking all over the city.

Water department officials use this recycled water, free of nitrates and other contaminants, to irrigate parks, schools and other facilities. Once demand is fulfilled, an estimated 38 million gallons a day is released downstream of Tucson. Pumping a fraction of that total upstream to bring a steady flow of blue back to the city's urban core can be achieved through an already-existing system of pipes.

According to McCusker, this will not only bring a portion of the river back to life — complete with mesquite trees and animal life — but will also help recharge the region's groundwater stores.

"This can help recharge the aquifer and create a tourist draw," he added. "It has appeal. The pipelines are already in place. It's just a matter of making a decision."

Countdown to splashdown

The Santa Cruz River, dry throughout most of the year except after heavy rains, will soon once more continuously flow through downtown Tucson. The Santa Cruz River, dry throughout most of the year except after heavy rains, will continuously flow once again in downtown Tucson. (Photo: Google Streetview)

With near-unanimous support across local government, a permit from state officials to discharge water through Tucson is expected to get the green light. Because the project's organizers are unsure just how far the 3.5 million gallons will travel before soaking into the river bed, it's expected that additional discharge will be required downstream to complete the river's journey through Tucson's urban core. Either way, the act of simply adding a continuous stream of water to a dry river bed should spark a dramatic uptick in natural green not seen in downtown Tucson in almost a century.

"Vegetation growing up, birds and other wildlife becoming attracted to that, it's amazing how quickly things transform in the desert when you just add water," Tucson Water spokesman James MacAdam told KVOA.

Should everything go according to plan, officials hope to have the Santa Cruz River flowing through Tucson by May 2019.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.