Three generations of the León family spread across a few picnic tables next to a small lake, enjoying some rare shade in hot, dry Hermosillo.
The Sonoran capital was unusually hot last month — temperatures hit 110 degrees at one point, a record for April. That’s more than 10 degrees hotter than Phoenix on that same day. Like Phoenix, the city has struggled with years of drought, making pockets of urban wetland like this one feel precious.
Juanita León says the family hasn’t been back to this space for years, when her kids played in pools and water slides. This sprawling park was left abandoned for over a decade, but officials recently started the process of refreshing it for a new generation.
“The moment I heard we could visit this space, I knew we had to take advantage,” León said.
The beginning stages of the reopening include batting cages and go karts, but also a reforestation project — the governor plans to plant more than 4,000 native trees here.
Spaces like this are rare in growing Hermosillo. Across the city, low buildings buttress wide boulevards, leaving little shade. That contributes to the urban heat island effect, the phenomenon of cities feeling hotter than surrounding rural areas.
The fact that so much of Hermosillo is made up of artificial surfaces — concrete and asphalt, for example — rather than natural surfaces makes the city hotter, scientists say. That’s especially true during the day, when temperatures can soar past 100 degrees for days on end.
As Hermosillo’s population swells close to a million, how it’s growing exacerbates the problem, according to Universidad de Sonora researchers Irene Marincic and Laura Mercado. Rather than its buildings getting taller, much of the growth has been on the outskirts, pushing hot surfaces like concrete and asphalt further into the desert.
Growing up — rather than out — could help alleviate the urban heat, the two say under the shade of one of the city’s new high-rises. The dearth of comfortable outdoor spaces means people spend more time inside.
“They’re consuming more air conditioning, adding to environmental contamination,” Mercado said.
Hermosillo’s population grew almost 20% between 2010 and 2020, according to government data, almost doubling Phoenix’s growth.
The city “cannot grow more,” said Universidad de Sonora atmospheric scientist Carlos Minjarez.
“This is a very hard political decision, and I understand why politicians don’t want to make that decision,” Minjarez said. “But I think the problem is getting critical.”
For at least a decade, the region hasn’t gotten enough rain to replenish the groundwater that flows through its pipes, Minjarez said. The city’s sources of surface water are also flagging, since Hermosillo’s rainy seasons are proving less rainy. The city got less than half the rainfall it typically gets during the last two rainy seasons, he noted.
The last time Hermosillo’s drought was this bad was in the middle of the last century, Minjarez said, when the city’s population was a fraction of what it is now.
“The takehome message here is that we have to try to do a very good water management for the next year,” Minjarez said, conserving water during monsoon seasons and using it “very carefully” when it’s dry.
This question of how to manage Hermosillo’s water — and how to get more of it — is going to get even more important as time goes on.
Researchers like Minjarez are still studying to what extent climate change is responsible for this particular drought. But overall, his models show what other researchers are finding: over the next 100 years, the weather will get less predictable — including longer droughts and more extreme rain.
As this summer’s rainy season approaches, city officials are pulling out new tools to try to conserve the water that they have. More water may also come through new dams that are in the works, but nearby rural communities worry those plans will leave them high and dry.
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South of the border, in the Mexican state of Sonora, the city of Hermosillo is dealing with ongoing water shortage and the various ways it impacts all walks of life. KJZZ’s Nina Kravinsky recently reported an illuminating series of stories about how drought is shaping life there, and joined The Show to discuss. -
Officials are trying to shore up a long-term water supply solution for the growing capital city of Hermosillo. But in the town of Banámichi, ranchers and residents are worried quenching the city’s thirst will leave them high and dry. -
The Sonoran capital’s water utility is working to shore up its supply in case a yearslong dry spell continues. Experts say it has its work cut out for it.
