Construction of stepwells involved not just the sinking of a typical deep cylinder from which water could be hauled, but the careful placement of an adjacent, stone-lined “trench” that, once a long staircase and side ledges were embedded, allowed access to the ever-fluctuating water level which flowed through an opening in the well cylinder. the steps sometimes to the surface.
In dry seasons, every step—which could number over a hundred—had to be negotiated to reach the bottom story. But during rainy seasons, a parallel function kicked in and the trench transformed into a large cistern, filling to capacity and submerging.
This ingenious system for water preservation continued for a millennium.
where they first appeared as rudimentary trenches
While some stepwells near areas of heavy tourism are well maintained,