[Chand Baori Stepwell in Abhaneri, Rajasthan, India via Creative Commons]
As the looming threat of global warming persists, one of the most prominent effects has been the erratic nature of weather patterns with pronounced emphasis on weather extremes. Some areas of the world are accustomed to such polarity. In Western India, for instance, three months of a healthy monsoon is followed by nine continuous months of arid weather. The polarization of weather promotes renewed interest in ancient infrastructures that could mitigate these extremes through sustainable means. In the case of the dry weather in Western India, this was done with Stepwells.
[Panna Mia Stepwell, Plan + Section]
Dated to 600 AD, stepwells are essentially inverted ziggurats excavated from the earth, producing an infrastructural monument to water collection. Like most great inventions, the concept driving a stepwell is surprisingly simple and composed of two parts – a well and access route. The large well is used to collect monsoon rain, which then percolates through layers of fine silt (to screen particulates), eventually reaching a layer of impermeable clay. Eroded rock from the Western Himalaya, further refined through several centuries of farming has produced a fine alluvium soil for the wells, which acts as an ideal filter. With larger sediment gathering at the top, the stepwell operates like an underground aquifer.
[Alternate Stepwell Section, Adalaj Wav Stepwell via Vatsu Shilpa Foundation]
The second component of the stepwell, are the steps or access passages to collect the water. Unlike traditional wells, stepwells allow one to enter, manage and maintain the well, creating a spatial occupation of the infrastructure. Some stepwells contain continuous transport infrastructure, such as ramps, to allow cattle to reach and transport water. More elaborated stepwells host galleries and chambers surrounding the passageways that were ornamentally sculpted. It is no surprise that these wells that allowed communities to sustain their crops during the arid months, eventually became religious temples dedicated to water. The functional characteristics of stepwells, soon made them a metaphor for the Ganges – the largest and most divine river in India.
[Temple stepped tank of the Vijayanagara Empire via Creative Commons]
What is intriguing about stepwells is that they were both an infrastructure to collect water as well a space of gathering and leisure. As a subterranean landscape, the base of the inverted pyramids provided a cool microclimate to escape the hot conditions at grade. As such, these became central public spaces of gathering and architectural significance. The collection of water also attracted large ecosystems of bees, fish, lizards, parrots, pigeons, and turtles amongst other species. Each monsoon would reinvigorate these stepwells and promote new life. As a functional, religious and social infrastructure, these became the central spaces for many communities to gather, bathe and converse.
[Step structure accounts for varying water levels, Chand Baori Stepwell]
The British Raj phased out the use of stepwells during the 19th century due to concerns over water borne parasites. Beyond the architectural beauty of stepwells, was an infrastructural intelligence, which is of importance today. These wells acted as water filters as well as mega storage and irrigation tanks in a completely sustainable manner. As weather patterns continue to polarize, these local infrastructures could provide clues on how to handle and store water for irrigation. For further reading, Morna Livingston has a great book on Stepwells, which I highly recommend.
[Deepest Stepwell in India, at Chand Baori, 11th Century AD]
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Via InfraNet Lab
Personal comment:
Etonnant encore une fois de constater à quel point les architectures vernaculaires, antiques, etc. (pour faire simple, les architectures pré-industrielles et surtout pré-climatisation) fonctionnait comme des systèmes socio-climatiques, économes avec les ressources et souvent intelligents. Des systèmes générant par ailleurs parfois des formes assez hallucinantes et radicales, comme ici.
Des choses à apprendre des anciens?