Data Centres Are Physical Infrastructure. Their Water Demand Proves It.
As data centres scale, their most important constraint is not computing power, but water. Cooling demand, location, & local hydrology ultimately shape whether digital infra can operate sustainably.
Data centres are often discussed within the context of digital infrastructure. In practice, they are among the most resource-intensive physical systems currently being built.
But at a technical level, data centres are intensely physical. Servers generate heat continuously, and managing that heat is central to their operation. In many facilities, cooling still depends heavily on water.
Cooling, explained simply
In water-based cooling systems, water absorbs heat from servers and associated equipment before being discharged, treated, or recirculated. Even with efficiency improvements, the volumes involved remain substantial.
A commonly referenced benchmark is around 26 million litres of water per year for every megawatt of capacity. This is not an extreme estimate; it reflects typical operating conditions for large facilities using water-intensive cooling.
As we scale to tens of megawatts, water demand becomes comparable to that of entire residential districts.
Why location changes everything
From a systems perspective, total water use tells only part of the story. Location matters more.
Many of India’s data centres are clustered around large urban centres - Bengaluru, Delhi NCR, Chennai, Pune, Hyderabad. Several of these cities are already classified as highly or extremely water-stressed. In Bengaluru, groundwater extraction exceeds annual recharge, and surface water is pumped over long distances at significant energy cost.
Introducing large, continuous industrial water users into such contexts alters local water balances in ways that are difficult to correct later.
Treated water is not a silver bullet
Using treated or non-potable water for cooling is often presented as the solution. It is necessary but not sufficient.
Treated wastewater depends on upstream sewerage networks, treatment capacity, and seasonal flows.
Without clear allocation rules and pricing signals, shifting data centres to treated water risks creating new pressure points rather than resolving scarcity.
Signals from elsewhere
Recent cases from regions hosting dense data centre clusters have highlighted health and environmental risks linked to cooling water discharge. Poorly managed discharge has been associated with changes in soil and groundwater quality, with impacts becoming visible only after years of operation.
The exact pathways may differ across geographies, but the lesson is consistent: cooling water is not a neutral by-product. Its sourcing, treatment, and disposal require active oversight.
Designing for constraint
The central infrastructure question is whether data centres are being designed for the water systems they actually sit within, or for an assumption of abundance that no longer holds.
Efficiency improvements and alternative cooling technologies matter. But without location-sensitive planning and enforceable safeguards, technology alone cannot resolve structural water stress.
Digital infrastructure does not sit above physical systems.
It is embedded within them.
Ignoring that reality only delays when the constraint becomes unavoidable.
There are no easy answers here, only trade-offs that need to be confronted early. I’d welcome thoughts and perspectives from others working in this space.
