Water from a natural spring flows down Desert Crest Drive in Tucson. Residents thought it was a leak from a pipe and called the emergency line at Tucson Water. This year’s monsoons have produced more water flow than usual.

 Mamta Popat, Arizona Daily Star

When residents on Desert Crest Drive saw water flowing down their west-side street last week, they did exactly what the public service announcements told them to do: They called the Tucson Water emergency line to report a leak.

But neighborhood old-timers knew better.

It’s not a busted pipe that’s filling the gutters along this residential street off Starr Pass Boulevard. It’s a natural spring that has bubbled back to life during Tucson’s third wettest monsoon on record.

Recent monsoon rainfall has revived a natural spring on a residential street near Starr Pass.

Only this time, the water is coming up in more places and lingering longer than anyone here can remember.

Ernie Almada grew up on Desert Crest and now lives in the same house his parents had built there in the early 1970s. He said the spring across the street seems to flow every few years, usually after a string of heavy rains.

But “it’s never lasted this long,” and it’s never come up on his side of Desert Crest like it is now, he said. “The water department has been out four times I think.”

Even before Saturday’s big storm, cool water was still seeping from the bare ground and cracks in the pavement in several spots along Desert Crest between Northview Avenue and Saint Tropaz Avenue. From there, it trickles downhill, following the slope of the road for about 400 feet before bending north into an alley on its way to Silvercroft Wash.

Though Almada worries about a sinkhole opening up beneath their street one day, he said the spring has never caused any serious problems for the neighborhood. It produces some wispy green algae and leaves behind mud in places, but it seems harmless otherwise.

On the map

“That’s one of the things that tells you it’s not Tucson Water,” said 25-year Desert Crest resident Charlie Smith. “If it’s got algae and stuff growing in it, it’s not Tucson Water.”

City drinking water has chlorine in it to prevent such growth, Smith explained.

He lives two houses downstream from Almada. When he and his wife, Jodi, first noticed the phenomenon years ago, he figured someone up the hill from them was emptying a waterbed or a swimming pool into the street.

Then he pulled out a map.

Water from a natural spring on Desert Crest Drive attracts butterflies. “It’s the desert. When you get water, things happen,” says Charlie Smith, who has lived in the neighborhood 25 years.

Smith said the feature shows up as an intermittent stream on a 1948 topographic map from the U.S. Geological Survey. You can probably trust him on this, too. Until he retired in 2019, Smith owned and operated the Tucson Map & Flag Center on First Avenue near Fort Lowell Road for 30 years.

He said even a single rain event can bring their spring to life, especially during a wet year.

“One good storm will put water back into the ground, and then it comes back out of the ground here,” Smith said.

Almada said his mother used to tell him about another natural spring between their house and the one next door, but he’s never seen that one flow.

Maybe that’s what he is seeing now. The water on his side of the street seems to be coming from a few different places in front of his house, forming a puddle on the sidewalk and attracting dozens of native yellow butterflies known as cloudless sulfurs.

“This is the most butterflies I’ve ever seen,” Almada said as he worked in his front yard on Wednesday.

Out of bedrock

Julia Fonseca is environmental planning manager for Pima County’s Office of Sustainability and Conservation. She’s also a trained geologist and hydrologist.

She said springs are more common in Southern Arizona than people might think, and this year’s monsoon may be restarting some that haven’t been seen in a while.

In 2000, Fonseca helped inventory more than 250 natural springs as part of the county’s Sonoran Desert Conservation Plan. The seep on Desert Crest wasn’t one of them.

More than a week has passed since the last rainfall here, but cool water still seeps from the bare ground and cracks in the pavement in several spots along Desert Crest between Northview Avenue and Saint Tropaz Avenue on Tucson's west side.

“This is not a known spring,” she said, at least not outside the neighborhood.

Most of the springs Fonseca cataloged are in eastern Pima County and most are intermittent, only flowing for days or weeks at a time when conditions are right.

She said the ones around Tucson tend to be on or near the mountains, close to bedrock, though Agua Caliente Spring, on the east side of the city, gushes warm water up from a fault line.

Whether springs flow or not is influenced by geology, climate and human activity such as land development and groundwater pumping, she said.

Some springs have gone dormant — or dried up altogether — as a result of the ongoing “megadrought” in the Southwest and rising temperatures from human-caused climate change, Fonseca said.

Free water

Based on the volume of water, the primary outlet for the Desert Crest spring is somewhere right behind Dave Peña’s back wall.

Peña used to work for the city water department, so the first time he saw water running down his street — decades ago now — he reported it right away.

Once he learned it was a natural flow, he figured the water was fair game.

“Years ago, I used to put out a hose with a funnel. I’d use it for my wife’s plants,” said Peña, who has lived on Desert Crest since 1978.

The evidence of water lurking close to the surface here is actually pretty easy to see, once you know what to look for. This short stretch of Desert Crest Drive is lined with some of the tallest trees in the neighborhood, including several towering mesquites and, in the corner of Peña’s backyard closest to the spring, a giant, bushy desert willow.

“These trees have never been watered,” he said.

Peña is so used to having a spring on his street that now he’s just waiting for it to dry up again so he can cut down the tall weeds that have sprung up along the marshy sidewalk next to his house.

Until then, there’s not much to do but sit back and watch the butterflies swoop in for a drink and sun themselves on the wet pavement.

“They just showed up,” Smith said, admiring the show. “It’s the desert. When you get water, things happen.”

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Contact reporter Henry Brean at hbrean@tucson.com or 573-4283. On Twitter: @RefriedBrean