The standard version of the fashion water story goes like this.
Cotton is a thirsty crop. Growing enough of it to make a single T-shirt requires around 2,700 litres of fresh water — several years’ worth of drinking water for one person. Scale that across billions of garments and the global fashion industry ends up consuming approximately 79 billion cubic metres of water per year, much of it drawn from regions that cannot spare it. The lesson is usually presented as being about cotton, and the implication is that the solution lies somewhere in more efficient cotton farming or in growing less cotton in the first place.
This picture is not wrong. It is just not the most important part.
Because in the specific accounting of where water is actually consumed and polluted across a garment’s manufacturing chain, cotton cultivation turns out to be less than half of the story. The rest of it — the parts most people never think about — is what happens after the cotton is picked.
The stage most people never think about
Between raw cotton fibre and a wearable T-shirt, textiles pass through a series of processing stages collectively known as wet processing. Fabric is scoured to remove natural waxes and impurities. It is bleached. It is dyed. It is printed on. It is finished with chemical treatments that give it its final texture, colour-fastness, wrinkle resistance, water repellency, or antimicrobial properties.
Every one of these stages requires large quantities of water.
According to a comprehensive 2025 review published in the journal Sustainability, wet processing accounts for approximately 72 percent of the total water demand in textile manufacturing. Cotton cultivation — the part everyone talks about — accounts for the remaining 28 percent. The specific stages where most textile water is actually used are not agricultural fields. They are the dye baths, chemical treatment tanks, and rinse cycles of factories, most of them clustered in a small number of manufacturing hubs across South and East Asia.
Dyeing alone consumes 30 to 50 litres of water per kilogram of cloth, depending on the specific dye and technique. A medium-sized textile mill producing 8,000 kg of fabric per day uses approximately 1.6 million litres of water daily, with 16 percent of that going into dyeing and another 8 percent into printing. Multiplied across the global industry, the water volumes involved in these post-cotton stages exceed everything spent on the crop that supplied the fibre in the first place.
What the water carries back out
The dyeing and finishing problem is not only that these stages use a lot of water. It is what happens to the water afterwards.
Textile dyeing is now the second-largest polluter of water globally, exceeded only by agriculture. A single ton of dyed fabric can generate approximately 200 tons of wastewater. That wastewater is heavily contaminated with the specific chemicals used in the dyeing and finishing processes: synthetic dyes themselves, heavy metals including lead and chromium, formaldehyde used in wrinkle-resistant treatments, chlorinated solvents used in scouring, and aromatic amines from the breakdown of azo dyes.
Approximately 700,000 tons of textile dyes are produced globally each year. An estimated 280,000 tons of that — roughly 40 percent — ends up discharged into surface water, in most cases without adequate treatment.
The geography of that discharge is not distributed evenly. Most textile dyeing happens in China, Bangladesh, India, Pakistan, and Vietnam. In Bangladesh alone, garment factories consume approximately 1,500 billion litres of water per year, much of which is returned to local rivers and streams laden with dye effluent. Satellite images of specific river systems near textile clusters in Dhaka show water that runs red, blue, or black depending on the current season’s fashion colours upstream. Local drinking water sources, agricultural irrigation, and coastal ecosystems all receive the downstream consequences.
According to the Quantis International 2018 impact assessment of the fashion industry, dyeing and finishing account for approximately 36 percent of the industry’s total global pollution impact — nearly two and a half times the impact of fibre production itself. Yarn preparation contributes another 28 percent. Cotton cultivation, despite dominating the popular framing of fashion’s environmental cost, accounts for around 15 percent of the total pollution burden.
The environmental problem the fashion industry actually has, in other words, is not primarily an agricultural problem. It is a manufacturing problem — and specifically, a wet processing problem.
What is being tried
The technical solutions to the wet processing problem are known and, in some cases, already deployed at industrial scale.
Waterless dyeing using supercritical carbon dioxide is the most advanced. Instead of water, CO₂ is pressurised to a specific state — neither liquid nor gas — in which it can dissolve and carry synthetic dyes into fabric fibres directly. The DyeCoo Textile Systems company in the Netherlands has been operating industrial-scale supercritical CO₂ dyeing lines since the mid-2010s, primarily for polyester. Nike, Adidas, and several other major brands have partnered with the technology, and small volumes of commercially available garments dyed this way have been on the market for several years.
Other approaches include digital printing, which applies dye directly and precisely rather than immersing fabric in a bath; foam dyeing, which uses air-based foam as the carrier rather than water; ultrasonic dyeing, which uses sound waves to drive dye penetration with reduced water and chemical loads; and dope dyeing for synthetic fibres, in which the colour is added at the melt stage before the fibre is spun, eliminating a separate dyeing step entirely.
Adoption remains limited. Waterless dyeing is more expensive per unit than conventional techniques, and the specific capital investment required to convert a factory is substantial. Fast fashion economics — which prioritise speed and per-garment cost over environmental performance — actively push in the wrong direction. Regulatory pressure varies by country. Consumer awareness of the wet processing problem, distinct from the cotton problem, is essentially zero.
The specific outcome of these dynamics is that the technology to substantially reduce the fashion industry’s water and pollution footprint exists. Whether it gets deployed at anything approaching the scale needed depends on decisions being made in specific factory investment plans, brand sourcing policies, and government regulations, most of which are not yet moving fast enough to matter.
The 2,700 litres of water in a single cotton T-shirt is a real figure. But most of it is not being used to grow the cotton. It is being used to turn the cotton into a T-shirt, and much of what comes back out of that process is not water any more. It is dye effluent, chemical wastewater, and heavy metal contamination, discharged into the specific rivers of the specific countries where the specific garments in most of our wardrobes were made.
The next time the fashion water footprint is discussed, in other words, the more useful question is not how much water was consumed. It is what came back out.
