An Eden Under Threat
XOCHIMILCO, Mexico — With their gray-green waters and blue herons, the canals and island farms of Xochimilco in southern Mexico City are all that remain of the extensive network of waterways that so awed Spanish invaders when they arrived here 500 years ago.
But the fragility of this remnant of pre- Columbian life was revealed in January, when a six-meterdeep hole opened in the canal bed, draining water and alarming hundreds of residents who depend on the waterways for a living.
The hole revived worries about a process of decline, caused by pollution, urban encroachment and subsidence, that residents and experts fear may destroy the canals in a matter of years.
“This is a warning,” said Sergio Raúl Rodríguez Elizarrarás, a geologist at the National Autonomous University of Mexico. “We are driving the canals towards their extinction.”
Xochimilco, a municipality on the southeastern tip of Mexico City, is home to more than 2,400 hectares of protected wetlands, hemmed in by dense streets. Here, farmers grow rosemary, corn and chard on chinampas, islands formed from willow trees, lilies and mud, a technique dating from the Aztecs. Residents ply the area’s 160 or so kilometers of canals in canoes, much as they have for centuries. On weekends, thousands of tourists picnic and party on brightly painted barges, or trajineras.
“This is the last thread that connects us to our pre-Hispanic past,” Ricardo Munguía, a tour guide, said recently while piloting his motorboat through the dawn mist. “It would be heartbreaking to lose this.”
As bucolic as the canals appear, intense exploitation of the area’s aquifers over the last 50 years has depleted springs, prompting the authorities to replenish the waterways from a nearby sewage treatment plant.
Built on a silty lake bed, Mexico City has been sinking for centuries. To slow the collapse in the city center, parts of which dropped about eight meters during the last century, officials in the 1960s shifted water extraction from downtown to wells near Xochimilco, a decision experts called a “death sentence” for the canals.
Despite a ban on construction on the chinampas, more and more of the islands are being settled as small-scale farming becomes less competitive and demand for residential space grows.
With every farmer who stops cultivating the chinampas, “we lose a part of our identity,” said Félix Venancio, an activist trying to protect them.
Xochimilco, which was designated a World Heritage site by the United Nations in 1987, has had no shortage of preservation plans over the years, but they remain half- complete, and funds “get lost along the way,” said María Guadalupe Figueroa, a biologist at the Autonomous Metropolitan University. “There’s a huge amount of corruption.”
She figures that, without a serious conservation effort, the canals will be gone in 10 to 15 years. But much of the damage was reversible, she said, adding: “It’s still a little paradise.”