Reclaimed water started running in the dry Santa Cruz riverbed hours before originally planned, providing plenty of water for a city ceremony heralding the Santa Cruz River Heritage Project.

The following column is the opinion and analysis of the writer.

Last Monday, 300 people watched the city of Tucson launch the Santa Cruz River Heritage Project by releasing water into the river near the base of Sentinel Peak. For millennia, our city’s heritage has been inextricably linked to the Santa Cruz River. The new flow is modest, a small ribbon of freshly cleaned, recycled wastewater from the Agua Nueva Water Reclamation Facility. Nonetheless, it is a persistent source of water pouring from the outfall — reliable in an environment where streams are seasonal, flash floods are violent but over quickly, and rain is treasured but unpredictable.

Within hours of the water’s release, dragonflies and coyotes were spotted, arriving as if on cue to show us what is possible. And hundreds of people crowded along the banks and even waded in to the now-flowing stream.

Despite the river having gone dry over a half century ago because of Tucson’s growing population and persistent aridification, those fortunate enough to have deep roots in the Tucson area hold the memory of it as it once was.

Historically, the Santa Cruz would flow reliably and meander through Tucson. Stories from back when the river still flowed are vivid and alluring: Storm surges would topple cottonwood trees the size of Parthenon columns. Families would watch pony races in the Elysian Grove after having a swim in its pools. You could catch a Santa Cruz “sand trout” with a horny toad on a string.

This week, we were reminded that the river’s legacy continues to unfold.

What can we hope to see in the future? The 2009 upgrades to the Nogales International Wastewater Treatment Plant and 2013 upgrades to two wastewater reclamation facilities in Pima County are delivering ultra-clean effluent that flows north from Rio Rico and from Prince Road, respectively. Many people don’t know that there are already 22 miles of flowing river in Tucson and Marana, whose improving conditions are documented in the Sonoran Institute’s Living River report series.

The flowing sections have brought back life with native plants and lots of shade. The advances in water quality shepherded the return of the pollution-sensitive Gila topminnow and native and migratory bird species, as well as spurring a call for river access for fun-loving humans. Seeing these improvements unfold made the reintroduction of water near downtown possible.

The Santa Cruz has a chance to once again unite many along its course northward to meet the Gila River. It is our duty as the recipients of thousands of years of heritage to continue to use our smarts, goodwill, and resources to protect, restore and reconnect with the river that will sustain us for generations to come.

Luke Cole is associate director of Resilient Communities and Watersheds for the Sonoran Institute. Contact Cole at lcole@sonoraninstitute.org