Nabataeans: From Caravan Leaders to Oasis Managers

Little is known about the Nabataeans until 312 BC, when they thwarted an invasion led by a Macedonian ruler at their mountainous fortress of Petra. This suggests that Petra was already a significant settlement at that time.

In the documentary series Civilizations Legacy: From the Nabataeans to the Jordan, archeologist Martha Joukowski from Brown University describes the Nabataeans as expert caravan traders.

They facilitated the movement of goods from distant lands, including silk from China, commodities from the Kingdom of Sheba, and various items like horses, copper, iron, and spices. Yet, these nomadic merchants established Petra for several strategic reasons:

• To create a secure location for storing goods and seeking refuge.
• To provide safety to fellow traders for a fee.
• To control caravan routes from the Arabian Peninsula to Syria and beyond.

Thus, the Nabataeans evolved from simple delivery agents to the proprietors of a vital rest stop in the unforgiving desert, a transition that proved lucrative.

By the first century BC, the Nabataean kingdom experienced significant growth, especially in the two centuries that followed, until it was annexed by Rome in 106 AD. Many of Petra's iconic structures were hewn from sandstone during this period, with the population reaching around 30,000—a feat requiring advanced hydraulic engineering capabilities.

The Dynamics of Water Management

According to Dr. Leigh-Ann Bedal, an archeologist at Penn State University, Petra currently receives approximately the same amount of rainfall as it did at its peak—around 100 millimeters, or roughly four inches, annually. Despite this scarcity, the city had ample drinking water and extravagant displays.

The Nabataeans ingeniously harnessed four natural springs in the nearby mountains to capture rainwater, though these springs were several miles away and necessitated an aqueduct system to transport the water into the city.

Unlike the Romans, who elevated their aqueducts, the Nabataeans constructed theirs close to the ground, resulting in over fifteen miles of carved channels within the surrounding rocks, along with numerous cisterns to store collected water.

Interestingly, they also built dams to redirect sudden flash floods during rare heavy rains. Dr. Bedal noted that the Nabataeans' water management strategies were so effective that they became a tool for showcasing their prowess.

On a large terrace once thought to be a market, Dr. Bedal and her team discovered that it was actually a garden and pool area.

This was no ordinary pond; the "grand pool" measured approximately 150 feet in length, 75 feet in width, and 8 feet deep, featuring an island adorned with a stone pavilion. Dr. Bedal speculates that this area was reserved for elite gatherings or banquets.

The garden surrounding the pool was lush, with evidence of palm groves discovered by the archeological team. According to Dr. Bedal:

> "The garden itself was a type of visual propaganda, a political statement about the conspicuous consumption of what was most precious."

This display positioned the Nabataeans as equals to the Hellenistic kingdoms nearby, but their hidden expertise in hydraulic engineering set them apart.

A Marvel of Ancient Engineering

Charles Ortloff, a research associate in anthropology at the University of Chicago, has explored the Nabataeans' hydraulic knowledge, which remains largely undocumented in historical texts. His research indicates that their engineering solutions often mirror modern techniques, suggesting they pioneered an unrecognized field of hydraulic science.

Ortloff’s work, utilizing computational fluid dynamics (CFD), revealed that while the Nabataeans initially relied on rock-carved channels, they later adopted terracotta pipelines, which introduced new challenges.

• These ancient pipes lacked threaded connections.
• They used socketed joints, likely sealed with hydraulic cement.
• Consequently, these joints were vulnerable to pressure.

The average pipe length was about one foot, and a single line from a spring (Ain Mousa) through the Siq could consist of nearly 42,000 connections, with significant elevation changes from the mountain springs to the city below.

The Nabataeans employed innovative solutions to address these issues.

Firstly, they established numerous cisterns and water collection sites throughout the city. These not only distributed water but also filtered out heavier particles in areas where the flow slowed. Each collection point served as a pressure relief for the pipeline, safeguarding the weaker joints.

Secondly, the Nabataeans crafted gradual angles in their water channels to mitigate flow speed. Ideally, if a pipe was not fully filled and had an air barrier above, there was reduced pressure. They perfected this technique, with a four-degree slope being optimal, whereas a six-degree incline could lead to failure.

During an episode of NOVA, Ortloff examined the angles of the terracotta pipes discovered in the Siq, noting they were precisely at four degrees.

While Petra's stunning architecture often captivates visitors, it is the sophisticated hydraulic engineering that truly defines its legacy. Together, these elements create a profound realization.

A Legacy Beyond Words

Many archeologists who have studied Petra express a common sentiment: the Nabataeans left behind few written records.

Not only did they neglect to document their achievements in writing, but they also refrained from carving many inscriptions into the stone they worked with. I believe this lack of documentation stems from their confidence—much like Muhammad Ali's assertion that true greatness doesn't require boasting if it can be demonstrated.

The Nabataeans had no need to document their magnificence; it was evident in their creations. Imagine emerging from the barren desert, traversing the Siq, and encountering monumental stone structures carved into cliffs—an overwhelming beginning.

While the outside world appeared lifeless, inside Petra, water flowed in abundance, allowing the Nabataeans to showcase it as a symbol of prosperity. Their access to precious water facilitated not only drinking but also artistic and recreational endeavors, creating a veritable oasis for weary travelers.

Petra boasted Olympic-sized pools, lush gardens, islands with pavilions, groundbreaking architecture, advanced hydraulic systems, and a thriving trade empire—all thriving in one of the planet's most inhospitable environments.

Why document greatness when the kingdom of water in the desert speaks volumes? Furthermore, Dr. Bedal notes that only about three percent of Petra has been excavated.

This raises the tantalizing possibility that many more wonders lie hidden beneath the sands.