Plumbing the ancient Mayan plumbing
Historians tell us the Spanish introduced pressurized water systems to the New World. But a new study indicates that the Maya were building pressurized pipes between about 450 and 750 AD, in Palenque, a major Mayan city in modern-day Mexico.
The Maya built a large number of cities in the Yucatan, Guatemala and Belize, before their cities were suddenly and mysteriously abandoned around 800. The Maya, whose descendants still live in the region, wrote with hieroglyphs, had extensive knowledge of astronomy, and their economy was strong enough to support cities such as Palenque, Chichen Itza and Cobal.
Until now, nobody had found evidence for pre-Spanish pressurized water in the New World, say the two authors of the new study.
The evidence takes the form of a narrow constriction in the underground Piedras Bolas aqueduct that routed water from a spring into Palenque. Unlike many Mayan cities, Palenque was built in low mountains, with only about 2,200 hectares of reasonably flat land. Untamed streams would gobble valuable real estate, so the Maya built limestone conduits to rout water through the city.
In some cases, the Maya plastered the inside of conduits with stucco to prevent leaks. And like modern builders, they Maya covered the conduits with stones that paved city streets and plazas.
Streaming, but not video
The suggestive constriction was six meters below the spring that supplied the stone pipe, and that height differential put the water under pressure, says co-author Christopher Duffy, a professor of civil and environmental engineering at Penn State University. The system is “analogous to a modern water distribution system. The water tower produces a ‘hydraulic head,’ or water pressure. The pipes go underground, and back up into the home, where water flows under pressure.”
The small opening at the bottom allowed the Maya to close off the conduit, so it would stay full of water. Air in the system will neutralize the hydraulic head, Duffy says.
Unfortunately, the Palenque site has been disturbed, and tantalizing questions remain, Duffy says. “We don’t know how they distributed the water from this point, but we can’t see any other purpose, other than as a control point in the buried conduit.”
Paving paradise to put up a … fountain — or a toilet?
Archaeologists already know that the Maya had an extensive irrigation system, fed by nine streams that ran through Palenque to the fields below.
The constricted conduit, one of nine, had a capacity of about 68,000 liters, and it alone could have stored enough water to supply scanty rations for several thousand people for a week during the dry season.
The pressurized pipe could have supplied a fountain where people could dip jars to collect drinking water. But the putative fountain was “probably beautiful,” says co-author Kirk French, a lecturer in anthropology at Penn State. “Everything the Maya did at Palenque was over the top, grandiose, in art and architecture.”
Fountains also serve a social purpose, says French. “They are in a central part of the city, where people can fill jugs and socialize. It’s funny, we refer to ‘water-cooler conversations,’ but it seems this has been going on for a very long time.”
Did the Maya’s pressurized plumbing have a more, er, “sanitary” function? “We don’t know the exact application,” admits Duffy, who specializes in hydrology, “although we were recently told, after the paper came out, that there are sweat baths, and perhaps toilets, in the palace at Palenque.”
In fact, the palace has “four toilet-like features,” French says, “They are in a line, at the right height, and share the same drain, but it’s hard to prove that they are toilets.”
The Piedras Bolas aqueduct
The sanity of sanitation
Toilets or not, the newly discovered plumbing shows that the Maya “are better engineers than they ever got credit for,” Duffy says. Although the Maya may have never seen pressurized water flow in nature, people are inventive, especially when it comes to something as important as water.
“We think this is the first example in the New World, but a lot more will probably be discovered,” says Duffy. “The Maya built like the Romans. They were practical. They would build, if it failed, they would build again. It’s a standard engineering strategy. Do something, fail, learn, and do it again.”
– David Tenenbaum