Setting an example

Two public buildings in Morelos — the Xochicalco pyramids museum and El Limón biological station — are examples of rainwater collection in action, and incorporate other eco-friendly practices. Underlying the museum, thirty-two kilometers south of Cuernavaca, is a 500,000-liter cistern.

“Bathrooms use the most water, about four liters per flush,” says museum director Marco Antonio Santos. With 800,000 yearly visitors, it adds up. Outside Morelos’ June through October rainy season, water is trucked from a nearby dam.

Water-cooled air keeps the museum’s interior between 20 and 25 degrees Celsius even when it reaches 42 degrees outside, thanks to a system designed by Cuernavaca architect Rolando J. Dada y Lemus.

The exterior and interior walls are separated by 20cm of space: cool air inside this void prevents the sun-bathed outer wall from transmitting absorbed heat into the museum.

Prevailing breezes are cooled while passing over shallow outdoor pools and channels along perimeter walls: this air enters the building through screened openings along its base and exits through openings in the skylights. Breezes also enter higher openings to evacuate warm air between a false ceiling and the roof.

Skylights illuminate the exhibit halls, housing some six hundred artifacts, and solar panels power computers, lights, and the cistern pump. Santos says there were no other options for water and power, the site being four kilometers uphill from the nearest town.

Flushing out waste

In remote El Limón, water consumption is curbed through the use of composting toilets. “Contamination is zero,” says Oscar Dorado, a Ph.D. biologist who helps oversee the 59,000-hectare Sierra de Huautla reserve, a tropical dry forest along the Morelos-Guerrero border. The station houses scientists and also hosts ecotourists: it can handle over one hundred guests at a time in fifteen guestrooms, each with two to five beds.

Dorado says the rain-collecting system is simple: inclined roofs, drains, and pipes carry water to the subterranean cistern, and drains collect rain that falls on the patio. Solar panels heat water for the kitchen and showers.

Dorado says the composting toilets in the bathrooms are odorless, and require only a cup of sand dumped in the bowl after use. The waste, composted with sand, lime, and ash, is removed every few months and disposed of on-site.

Schools can arrange one-day visits for $75 per student, plus $2,800 for transportation from Cuernavaca, with lunch available for $60 per person. Family tourism is $510 per person for weekend stays, including transportation and meals.

Activities include a thirty-minute introductory talk about the reserve and current research; a 1.5 kilometer walk to observe plants while a guide provides information; visits to an abandoned silver mine; trips to the nearby town of El Limón; environmentally- themed games; and campfires.

Information and reservations are available by phone through the Sierra de Huautla Environmental Education and Research Center (CEAMISH) in Cuernavaca at (777) 329-7019 ext. 3278 or through e-mail, educam@uaem.mx.

Getting there

To get to Xochicalco, drive south from Cuernavaca through Alpuyeca, then towards Miacatlán. Follow the signs to Xochicalco. General admission: $48 pesos. A nighttime light and sound show held October through May costs $160 pesos.

Rolf Olsen is a freelance journalist born in Mexico City and now based in Cuernavaca. He can be reached by email at olsen.rafa@gmail.com.