Discoveries

May 15, 2023

Harvesting Water

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Great Zimbabwe was the first major metropolis in southern Africa during the medieval period.

At its peak, the city had a population of about 18,000 and was home to ruling elites, religious leaders, and craftsmen between the 11th and 15th centuries.

But today it lies in ruins and scholars have wondered what caused the demise of the once-thriving metropolis.

Some researchers have suggested drought as the culprit. However, an international research team discovered that the population had a very good water system for periods of dry spells, Science Alert reported.

In their study, researchers described the presence of a series of large, circular depressions around the city that were used to capture water.

Initially believed to be sites for digging clay, these “dhaka” pits were strategically placed to collect rain and groundwater, as well as cordon off parts of rivers and streams.

The team also gathered more evidence that these pits were used for water collection after finding the remains of plants that thrive near sources of water.

So how much water did these dhaka pits hold?

While the authors do not have an exact figure they estimate the pits may have contained almost 5 million gallons of water.

Still, they noted that there is much more to learn about Great Zimbabwe and how the city declined.

Political and economic factors may have played a role but climate change has not been ruled out.

During this time, the Earth experienced the Medieval Climatic Anomaly and the Little Ice Age, which could have put the growing city under immense stress.

Scientists hope more research will solve the mystery of Africa’s first major city.

This story originally appeared in the May 15, 2023 newsletter, The Ephemeral Ballot.