From ancient wisdom flows modern water solutions

Highly sophisticated water management techniques of ancient civilisations demonstrate the ingenuity of inhabitants who lived with limited water. It appears we need to look to the past to ensure a stable water supply in the future.

Even in today's information age, there is much to learn from ancient civilisations, particularly when it comes to an essential resource such as water. For example, a recent study revealed how more than three centuries ago, Great Zimbabwe - the largest city in southern Africa during the Middle Ages - stored water in dhaka pits to overcome severe water scarcity and drought.

Professor Innocent Pikirayi of the Department of Anthropology, Archaeology and Development Studies at the University of Pretoria (UP) was part of the research team that discovered how the community of Great Zimbabwe maintained a stable water supply in a region known for periodic droughts and which is presently water-scarce.

The study was conducted in the context of growing water security challenges, currently among the most significant global challenges for human subsistence and environmental health. It highlights the importance of effective strategies for water management and conservation today.

"Our research - conducted with academics from Great Zimbabwe University, the University of Cambridge in the UK and Aarhus University in Denmark - has identified dhaka pits, which were part of the ancient city's water infrastructure," Prof Pikirayi says.

These infrastructures were originally interpreted as remnants of excavations of clay (dhaka) used to construct residences.

"However, recent archaeological surveys and excavations, geo-archaeological sampling, and remote sensing techniques like LiDAR (light detection and ranging) revealed that these depressions were part of a very complex, 'climate-smart' water management system," he adds.

Throughout history, human civilisations have engineered extraordinary water management systems that enabled urban growth, agricultural productivity and cultural flourishing.

"Among the Chinese, Armenians, Persians, Mesopotamians, Egyptians, Romans, Greeks, Aztecs, Incas, Harappans and other societies, there is evidence of sophisticated ancient water infrastructures that present valuable insights for addressing contemporary water disasters, water shortages, water quality and climate change," says Dr Meisie Rasakanya, an expert on modern water infrastructures. "As such, the civilisations associated with these societies survived for a long time."

Ancient societies had a thorough understanding of local hydrology and the need for the sustainable management of water. They were also able to accurately read changes to the environment and climate, and respond with long-term solutions to retain or conserve water sources and resources.

"This demonstrates resilience in the face of acute diversity, particularly during the Little Ice Age," Dr Rasakanya says. "The damming of water in a hilly place such as Great Zimbabwe is indicative of the ability by the ancients to minimise water losses, managing to retain it where sloping and gravity would have encouraged rapid water flows downstream."

The preservation of the dhaka pits in Great Zimbabwe is evidence of the durability of their construction - an engineering attribute required of all modern water infrastructures, given the challenges of variable rainfall patterns, most of which result in flooding.

"Lessons from Great Zimbabwe as well as other ancient civilisations that need to be put into practice include adopting water management as an integrated system and implementing a holistic approach, from harvesting to storage, distribution and discharge, rather than managing the resource in a fragmented and uncoordinated manner," Prof Pikirayi says. "Key to this integrated approach is involving communities, because they are integral to the development and sustenance of civilisations."

Why this research matters

Ancient water management systems offer valuable lessons for addressing contemporary water scarcity challenges in sub-Saharan Africa, particularly in urban areas that are facing similar environmental pressures. Using some of these lessons from the past, we can develop and implement more resilient, sustainable and equitable water management solutions for a world confronted with water scarcity and, in some cases, flooding.

Water-wise lessons from ancient societies

• Ancient Romans and Persians conveyed water to distant places by way of gravity-fed systems such as aqueducts and qanats.

• The Chimú Indians of Peru harvested nutrient-rich sediments from seasonal floods to fertilise farms and enhance the agricultural potential of soils.

• In Mesopotamia and other parts of Asia, ancient societies addressed water shortages and excesses by constructing canals and reservoirs.

• In sub-Saharan Africa, evidence of furrow construction and terracing shows how ancient societies relayed water and conserved moisture in regions that would be regarded as marginal for agriculture today.

• In Great Zimbabwe, the damming of water was critical in sustaining the ancient city for more than two centuries. This was in response to the onset of adverse climate events.

This story first appeared in RE.SEARCH Issue 12: Global.