There is a stepwell in Hyderabad that was, until recently, invisible.
Not physically — it had been standing for centuries. But functionally, institutionally, in the minds of the people responsible for managing the city's water — it simply wasn't there. Encroached on over decades, its water table disconnected from the surrounding groundwater system, its cultural significance known to historians and largely unknown to planners.
I was in Hyderabad to assess the water-positive impact of a CSR intervention: a pharmaceutical company had funded the stepwell's restoration alongside the ecological rehabilitation of an urban lake nearby. My job was to measure what had actually changed — in water volume terms, in groundwater recharge terms, in the terms that end up in an ESG report.
What I didn't expect was what the restoration revealed about urban memory.
What we were measuring — and what we found
The brief was relatively clear: quantify the net water-positive impact of two interventions. For the lake, that meant assessing pre- and post-restoration water storage capacity, estimating groundwater recharge contributions, and evaluating ecosystem services — flood attenuation, urban cooling, biodiversity recovery.
For the stepwell, it was more complicated. Stepwells are not just storage structures. They are hydrologically connected systems — designed, over centuries, to function as recharge wells, drawing monsoon water down through a series of steps into an aquifer below. The step design wasn't decorative. It was functional: it slowed the water, filtered it through the soil layers, and guided it down.
When a stepwell is encroached — built over, filled in, disconnected — it doesn't just lose storage capacity. It loses its position in the local water cycle. The aquifer below it, deprived of its recharge source, begins to decline. The surrounding area, which once relied on that aquifer, starts to experience water stress that no one connects back to the stepwell no one thinks about anymore.
"The aquifer doesn't know the stepwell has been forgotten. It just keeps declining."
Restoring the stepwell reversed some of this. Not all of it — decades of disconnection cannot be undone in one intervention. But the restored structure began doing what it was designed to do: receiving water, slowing it, pushing it down.
The methodology problem
Here is the honest thing about this kind of assessment: there is no established standard for measuring the water-positive impact of a heritage stepwell restoration. There are frameworks for lake restoration assessments. There are groundwater recharge estimation methodologies. But combining them for a structure that is simultaneously a heritage site, a surface water body, and a groundwater recharge mechanism — that required us to build something from scratch.
We calculated water storage restoration, estimated groundwater recharge contribution using soil infiltration rates and catchment area analysis, and documented the cultural heritage value as a co-benefit. The result was a methodology that could, in principle, be applied to other stepwell restorations across India — a country with thousands of these structures sitting forgotten in urban cores.
What cities forget
The deeper observation from Hyderabad is about institutional memory. The stepwell was invisible not because it was hidden, but because the urban water management system had been redesigned around its absence. Piped supply replaced groundwater. Drainage systems were built without accounting for the recharge function the stepwell once provided. The new infrastructure worked — mostly — and no one needed to remember what came before.
Until the piped supply becomes intermittent, the groundwater declines, and the city starts to experience water stress it cannot explain.
This is the pattern in Indian cities: infrastructure is built forward without accounting for what has been lost backward. The water memory of the city — the knowledge encoded in stepwells, in traditional drainage systems, in the seasonal logic of tanks and kunds — is not preserved anywhere that matters for planning decisions.
Call for Climate exists, in part, to recover some of that memory. Not as heritage preservation for its own sake — but because those old systems often understood the local hydrology better than the new ones do.
— Anirudh Soni, Founder, Call for Climate