In Peru, Kenya and India, NGOs are helping communities overcome water scarcity using wisdom from the past
Across large swaths of the Thar desert in western India, traditional techniques for harvesting the little amount of rain that falls has helped people survive the powerful effects of the sun for centuries.
The most beautiful of these are step wells – known as baolis in Hindi – large, stone structures built to provide water for drinking and agriculture. Baolis have existed for at least 1,000 years and were constructed in towns and alongside serais (travellers’ inns), across the desert and into Delhi.
Baolis exist in all shapes and sizes and are essentially reservoirs built into the earth. Groundwater is pulled up from a circular well at the bottom and rainwater is collected from above. A set of steps – on one or more sides of the structure – lead down to the water level, which fluctuates depending on the amount of rain. More recently, electric pumps have been installed in many baolis to help retrieve the water.
“Step wells are etched into people’s collective memory so deeply, they are now part of their DNA, passed on from one generation to another,” says Farhad Contractor of the Sambhaav Trust, an ecological conservation group.
Today, many baolis have fallen prey to rapid urbanisation and neglect. In Delhi only around 15 survive but local groups are fighting to protect and preserve them. While 700mm of rain falls on Delhi every year, half of the city has been declared a dark zone – where the groundwater level has depleted so much that the rate of recharge is less than the rate of withdrawal – by the groundwater authority. Rainwater harvesting, therefore, is key to a secure water supply for India’s second-biggest city.
One such baoli restored by the Aga Khan Trust for Culture (AKTC) was built in the 14th century in Hazrat Nizamuddin Basti, a medieval village in Delhi named after Sufi saint, Hazrat Nizamuddin Auliya. In 2008, parts of the baoli walls collapsed due to sewage water seeping into the structure and the local residents using it as a rubbish dump. The pool was drained and the rubbish, garbage and sludge that had accumulated over the past 700 years was removed to reach the foundation of the baoli some 80 feet below ground level. While the water in the baoli is still not potable, it can be used for cleaning and agriculture.
Experts say the baoli model can be replicated anywhere in the world with similar climatic conditions and physiological features. Contractor has been invited to Morocco where he is working on a project to build baolis and smaller wells, known as beris in Hindi.
But large baolis need large catchment areas, and in Delhi space is an issue. While the majority of the physical structures of baolis are protected – some by being sited inside historic monuments – urban development in Delhi has had a greater impact on their water levels; storm drains divert rain away from baoli catchment areas.
Diwan Singh, an activist with non-profit Natural Heritage First, says that even though many baolis in Delhi are surrounded by buildings, the wells can still be recharged. “Catchment area management is the key. In the small areas of land between the baolis and buildings, rainwater harvesting pits could be built to divert rainwater away from the storm drains,” he says. “Once in the pit, water will percolate through the soil and recharge the nearby baoli, allowing modern development and ancient structures to co-exist side by side.”
(This was one of the three parts of the original longer story published by The Guardian, which can be read here)