MEXICO CITY (AP) — After two hours' grueling drive southeast from the center of Mexico City, through paralyzing traffic jams and clouds of throat-burning smog, the bleached-white haze of air pollution gives way to pale-blue sky.
In a flat-bottomed boat tied to a willow tree, Crispin Matteos Galicia hauls up sediment in a plastic bucket to fertilize squash seedlings for his chinampa, an island farm built in the shallow waters flowing from the Lake of the Aztec Kings.
It's a routine that's played out for hundreds of years in the waters that used to cover the Valley of Mexico. But just over the treeline, the future is coming.
Inside a freshly built trainyard about a mile to the north, a massive crane lowers a bright-orange train car gently onto the tracks of the city's new subway line, a $1.7-billion project running 15 miles from the semi-rural borough of Tlahuac to the southwestern section of fully urbanized Mexico City.
The 20-station Line 12, or Golden Line, will open this summer, carrying some 437,000 passengers a day across the southern part of Mexico City, halving a commute that added up to more than four hours a day by bus or car for many people living in and around Tlahuac.
Its arrival is a sign that the slow rhythms of this unique little piece of Mexico City soon will come to an end.
Tlahuac is one of the last places in the world where people still farm chinampas, fields created by piling earth on a lakebed and fixing it with willow trees planted around the edges. Indigenous people and their descendants have grown zucchinis, melon, squash and other produce on chinampas in Tlahuac since pre-Hispanic times. But the number of chinampa farmers in Tlahuac has dwindled as the borough has grown and urbanized and residents increasingly make their living in more modern professions.
Antonio Palacios Martinez is one of the last people in Tlahuac to still make his living on the water, poling his wooden boat along the canals and pointing out coots, herons and moorhens for the handful of local tourists who hire him.
"Everybody used to know the chinampas and come to work in the chinampas, even the children," he said. "Now most of the young people are professionals. They don't feel like going to break their backs in the sun."
The heart of Tlahuac still looks something like a town in the Mexican countryside, complete with a quiet central plaza and a colonial-era church. But fast-food restaurants, dense cinderblock housing developments and bumper-to-bumper traffic are spreading down the main thoroughfare from Mexico City's center to Tlahuac, pushing almost through the borough of more than 360,000 people to the farthest eastern edge of the city, where it abuts the neighboring State of Mexico.
A few miles closer to the city center, the canals of the borough of Xochimilco are filled with tourists who come to what some call the Venice of Mexico to see what much of the valley looked like before the Spaniards started to drain it.
"Xochimilco's chinampas are already filled with houses," said Matteos, 42, as he prepared his chinampa's seedbed for planting. "If there's a lot of concrete here, water won't fill the aquifers."
It's a pattern that repeated itself for decades as Mexico City has sprawled out toward the edges of the valley, swallowing up small towns, complete with cobblestone streets and colonial squares, and turning them into traffic-choked neighborhoods of one of the world's largest urban areas.
The Golden Line is designed to make some of that growth more sustainable and environmentally friendly, creating an east-west public transit connection across the southern end of the Valley of Mexico, bringing train service to some of the city's most densely populated neighborhoods and allowing easier transfers between four lines that currently run north to south.
But Matteos said he also fears the effects on the environment and the end of his mostly rural lifestyle within the limits of Mexico City.
"The city is swallowing up all this land, which is the inheritance of all humanity," he said.
Worrying about the future is pointless, said Lupe Martinez, a 70-year-old farmer who was turning his dry melon field by hand a few hundred feet away. The Golden Line is progress, he said.
"For me it's a thing of beauty," he said. "It'll take you to every part of the city. I never thought I'd be able to get here on the metro."