This article is part of our Design special section about water as a source of creativity.
Years of abnormally low rainfall, higher-than-normal temperatures and aging infrastructure have led to a dangerously low water supply for Mexico City. The issue isn’t a new one for the Mexican capital — in 2014, it was ranked as the third most water-stressed of more than 150 of the planet’s largest cities. Now, the metropolis faces a water crisis so severe that local authorities recently began imposing rations.
For Javier Sánchez, a low-slung earthen house just west of Mexico City, designed by his architectural firm JSa, reflects an obvious way out of the predicament.
“This house is a laboratory because it allows people to visualize the possibility of going back to certain solutions that were implemented many years before us,” he said on a recent video call. “There was an ancient technology around water, but it was easier to put everything in pipes and forget about it.”
Chief among those technologies is the simple act of harvesting rainwater, which falls robustly in the region in summer. The house, which is situated within a 200-hectare (494-acre) nature reserve in the mountains of Valle de Bravo near the municipality of Temascaltepec, is connected to a system that captures, stores and recycles rainwater, making the property completely self-sufficient, in terms of water.
The sloping site has trenches that funnel rainwater from the terrain’s higher areas and from the home’s roof into a 15-foot-diameter reservoir next to the residence. Four cisterns in the basement store, filter and treat the water for use in the home.
“Once you see the water system working, you understand that it is possible and not so difficult,” Mr. Sánchez, 54, said. “But if I were to just explain it in words, people might be afraid because we have forgotten those ancient practices around harvesting water.”
The home’s owner, Enrique Olvera, 48, had no problem deciphering the message. The founder and head chef of the acclaimed restaurant Pujol in Mexico City, he is renowned for reimagining traditional Mexican cuisine.
“Javier and I are walking the same path,” he said on a video call.
A weekend home, the house is part of a development called Reserva Peñitas, which was designed to provide water self-sufficiency for 80 families. The community has an interconnected hydrological system with 12 reservoirs and a network of nine miles of planted bushes and hedges alongside low wetland marshes, allowing it to hold more than 30 million gallons of rainwater.
Each house has its own rainwater-capture apparatus, as well as access to the larger communal network. During rainy season, from May to October, many of the homes, including Mr. Olvera’s, harvest so much rainwater that the excess is fed back into the shared system.
“The surplus of water creates humidity, the humidity helps wildlife in the area, and it evaporates and becomes part of the clouds and eventually rain,” Mr. Sánchez said.
Or, as Mr. Olvera put it, “People have forgotten that water doesn’t come from the sky. Water comes from the earth.”
In the basement, the house’s chemical-free treatment system collects wastewater and converts it to gray water, for use in toilets, and the on-site orchard. There, with the help of the landscape designers Philodendro, Mr. Olvera has planted apple, pear, plum, citrus, avocado and macadamia trees.
While the site is designed to exploit rain, the house itself must be protected from it. It was built using rammed earth construction with golden clay that was found during excavation. The two-foot-thick walls naturally insulate the home’s interior and regulate hot and cold by leveraging the natural properties of clay.
“The walls must have two things: a base made of concrete, and a cover, because the walls cannot be in contact with rain,” said Aisha Ballesteros, the JSa partner who led the design.
The wide overhangs that shelter the earthen walls from rain also allowed Ms. Ballesteros to incorporate several covered patios, including an open-air dining area with a wood oven and grill where Mr. Olvera enjoys cooking for his family and friends.
Having worked with Mr. Olvera for nearly a decade — JSa designed five of his restaurants, including Pujol — Ms. Ballesteros has noticed a change in him lately. “He’s more relaxed and interested in the simple things in life as a luxury,” she said.
At his retreat, water becomes just such a luxury. The reservoir is lined with native wetland plants like water lilies and cattails, which help filter the water. During hot months, the reservoir doubles as a cold plunge pool. The site also includes an outdoor hot tub, an indoor sauna and a gym.
“It is a living process,” Mr. Sánchez said. “You feel the tension of life because you’re using the water at the same time you are enjoying it visually. It’s a functional landscape.”
For Mr. Olvera, this tension is his favorite part. “The whole experience of this place is about contemplation,” he said. “At the house, you are a part of the natural system; you cannot abstract yourself from it. That’s the beauty of being there.”
