Why a chip fab needs a water treatment plant at all. Semiconductor manufacturing needs ultrapure water — purity levels below one part per trillion of dissolved solids — for rinsing wafers between hundreds of processing steps, and it needs to treat what comes back out, which carries fluoride from etching, heavy metals, PFAS and high organic-carbon loads. Producing 1,000 gallons of that ultrapure water typically consumes 1,400–1,600 gallons of municipal input before recycling — the gap is reject water that has to go somewhere. A fab is, functionally, a water-treatment facility that happens to also make chips.

Water intensity scales with process sophistication, not just fab size. Generic industry figures put a single large modern fab at 20–38 million litres a day (MLD), with advanced-node processes running 4.5–7 litres of ultrapure water per square centimetre of wafer processed. But the fab India is actually building doesn't sit at that end of the range: reporting on the Tata Electronics facility in Dholera puts a single 28nm fab's requirement at 10–15 MLD of ultrapure water, alongside 100+ MW of continuous power — both figures reflecting the mature-node processes (28nm, 50nm, 55nm) the Dholera fab is actually targeting, not the 2–3nm cutting edge that drives the higher figures elsewhere. That distinction matters for everything that follows: comparing Dholera's capacity against TSMC's most advanced fabs would overstate the mismatch.

Taiwan's semiconductor sector is the clearest real-world data point for what fab water demand looks like at scale. Taiwan's total semiconductor industry water usage exceeds 250,000 tonnes a day (250 MLD); TSMC alone accounts for roughly 150,000 tonnes a day (150 MLD) across its Taiwan facilities. As of 2019 — the most precise sourced figure available, and now several years dated given how much TSMC's usage has grown since — TSMC's consumption represented 3.4% of Taiwan's total industrial water use, not of Taiwan's total water use; agriculture claims roughly 70% of the island's water on its own. At the site level, TSMC's original Hsinchu Science Park facility uses about 57,000 m³/day, itself around 10.3% of that region's daily reservoir supply — and TSMC's claim on the whole science park's water grew from 40% to 85% as the company expanded there.

That growth trajectory collided with reality in 2021, when Taiwan suffered its worst drought since 1964. Central and southern reservoirs fell below 20% capacity; the Tsengwen reservoir dropped to a 15-year low under 12%, and the Baihe reservoir ran completely dry. The government rationed water to over a million households and businesses in central Taiwan — taps cut for two days a week — and ordered the island's three major science parks to cut water use by up to 15%. TSMC kept its fabs running by trucking water in: 8,000 tanker trucks a day, each carrying 20 tonnes, adding up to roughly 160,000 tonnes of trucked water daily. The disruption landed in the middle of a global chip shortage that automakers in the US, Germany and Japan were already depending on Taiwan to resolve.

The response since has been concrete, dated infrastructure, not just policy statements. TSMC reported a 90.3% process-water recycling rate in 2023. Its Hsinchu Science Park Reclaimed Water Plant — the world's first industrial reclaimed-water plant built specifically for advanced semiconductor processes — was planned to supply 10,000 m³/day in 2025, scaling to 36,000 m³/day by 2026. A second facility, the Qiaotou Reclaimed Water Plant in Kaohsiung, is due to complete in 2026 with a further 25,000 m³/day. None of that replaces reservoir water outright; it reduces how much fresh water each additional wafer requires, which is the only lever that scales when the reservoirs themselves don't.

Dholera's dedicated infrastructure for the Tata Electronics fab is a 50 MLD water treatment plant plus desalination capacity, fed via the Narmada canal system into the Special Investment Region, which has also been granted a first-of-its-kind blanket environmental clearance covering the entire 920 sq km zone. Set against the mature-node fab actually being built there — the 10–15 MLD figure from Section 1 — that 50 MLD plant has real headroom, roughly three to five times the single fab's estimated need.

Dholera and Tata Electronics figures per Section 1's sourcing. Taiwan figures per Section 2's sourcing. These are not measured on an identical basis — Dholera's is installed treatment capacity, Taiwan's figures are consumption/usage — so the table is directional, not an exact like-for-like comparison.

The headroom looks comfortable for a single fab at Dholera's target node. It's exactly the kind of margin TSMC's Hsinchu site also had once, before the company's own expansion absorbed it. India's Semiconductor Mission (ISM 2.0) already builds in the right instinct on paper — infrastructure readiness requirements and water-recycling plants are part of the framework, and dedicated utility corridors are being developed at both Dholera and the Sanand ATMP cluster — but ISM's fiscal support (up to 50%) is aimed at getting fabs built, not at a specific water-recycling percentage target the way TSMC's 90.3% figure represents a company-level commitment. If Dholera attracts a second fab, or if Tata's own roadmap moves toward more advanced nodes over time, the comparison in this table is the one worth re-running — because Taiwan's experience is that the multiplier compounds faster than the base infrastructure gets rebuilt.