The Water Footprint of Your Wardrobe: A Material-by-Material Comparison

A garment's environmental impact is measured in many ways, but its water footprint—the total volume of fresh water consumed and polluted throughout its lifecycle—is one of the most significant. This metric reveals the hidden water costs from raw material cultivation to manufacturing, consumer care, and final disposal. While natural fibers like cotton are famously water-intensive at the agricultural stage, synthetic materials such as polyester carry a heavy burden in their grey water footprint, the volume of water required to dilute pollutants from manufacturing. Understanding this consumption is critical for a considered approach to material selection.

This article provides a quantitative comparison of the water footprints of six key apparel materials: cotton, polyester, wool, cashmere, leather, and down. It examines the water consumption across each stage of their lifecycle, drawing on data from life cycle assessments (LCAs) and academic studies to provide a clearer picture of the true water cost embedded in a wardrobe.

The Water Footprint of Cotton

Cotton is a natural fiber that is notorious for its high water consumption, particularly during the cultivation phase. The water footprint of cotton varies significantly depending on the region, irrigation practices, and whether it is grown conventionally or organically.

Production Water

The majority of cotton's water footprint is attributed to the agricultural stage. On average, it takes approximately 10,000 liters of water to produce one kilogram of cotton fabric [1]. A single cotton t-shirt can require up to 2,700 liters of water [2]. This water is primarily used for irrigation, especially in arid and semi-arid regions where much of the world's cotton is grown.

Care Water

The use phase of a cotton garment also contributes to its overall water footprint. Washing and drying cotton clothes consumes a significant amount of water and energy. The frequency of washing and the type of washing machine used can have a substantial impact on the total water consumption over the garment's lifetime.

End-of-Life Water

At the end of its life, cotton is biodegradable. However, the disposal process can still have a water footprint. If sent to a landfill, the decomposition of cotton can produce leachate, which can contaminate groundwater if not properly managed. Recycling cotton can help to reduce its end-of-life water footprint by offsetting the need for new cotton production.

The Water Footprint of Polyester

Polyester, a synthetic fiber derived from petroleum, has a significantly different water footprint profile compared to natural fibers. While its production requires less blue water, its grey water footprint, associated with pollution, is a major concern.

Production Water

The production of polyester fiber itself is not as water-intensive as cotton cultivation. However, the overall water footprint of polyester is dominated by its grey water footprint. The manufacturing process, from oil exploration and refining to petrochemical processing and fiber production, generates a substantial amount of polluted water. One study by the Water Footprint Network found that the water footprint of polyester can be as high as 71,000 cubic meters per tonne of fiber, with over 99% of this being grey water [3]. This is due to the toxic pollutants released during production, which require large volumes of water to be diluted to safe levels.

Care Water

Like cotton, washing polyester garments contributes to their water footprint. However, polyester fibers do not absorb as much water as cotton, and they dry more quickly, which can lead to lower water and energy consumption during the use phase. A significant issue with washing polyester is the release of microplastics into waterways, which is a separate but related environmental concern.

End-of-Life Water

Polyester is not biodegradable and can persist in the environment for hundreds of years. While polyester can be recycled, the process itself requires water and energy. However, recycling polyester is still preferable to sending it to a landfill, as it reduces the need for virgin polyester production and its associated water footprint.

The Water Footprint of Wool

Wool, a natural fiber from sheep, has a water footprint that is primarily associated with the farming of sheep and the processing of the raw wool.

Production Water

The on-farm water footprint of wool is mainly from the water consumed by the sheep and the water used to grow the pasture they graze on. The processing of wool, known as scouring, is also a water-intensive process. Scouring involves washing the raw wool to remove grease, dirt, and other impurities. It is estimated that it takes approximately 500,000 liters of water to manufacture a metric ton of wool [4].

Care Water

Wool garments generally require less frequent washing than cotton or synthetic garments, which can reduce their water footprint during the use phase. When washing is required, it is often done at lower temperatures, which also saves energy.

End-of-Life Water

Wool is a biodegradable fiber, and at the end of its life, it can be composted, returning nutrients to the soil. This makes its end-of-life water footprint relatively low compared to synthetic fibers.

The Water Footprint of Cashmere

Cashmere, a fine and soft fiber obtained from cashmere goats, has a complex water footprint that is influenced by both the agricultural and processing stages.

Production Water

The production of cashmere involves raising goats, which require water for drinking and for the growth of the vegetation they consume. The processing of raw cashmere into fabric also contributes significantly to its water footprint. A study on the water footprint of cashmere fabrics found that woven cashmere fabrics had a greater water footprint than knitted cashmere fabrics. The blue water footprint, grey water footprint, and water scarcity footprint of combed sliver dyed woven cashmere fabric were the largest among the ten kinds of cashmere fabrics studied [5]. The main pollutants contributing to the grey water footprint were total phosphorus, chlorine dioxide, hexavalent chromium, and sulfide.

Care Water

Similar to wool, cashmere garments require delicate care and less frequent washing, which helps to reduce their water consumption during the use phase. Hand washing or using a gentle cycle with cold water is typically recommended.

End-of-Life Water

Cashmere is a natural, biodegradable fiber. At the end of its life, it can decompose naturally, and like wool, has a lower end-of-life water impact compared to synthetic materials.

The Water Footprint of Leather

Leather, a durable material produced from the tanning of animal hides and skins, has a substantial water footprint, particularly in the farming and tanning stages.

Production Water

The water footprint of leather begins at the farm, with the water required to raise the animals. The water footprint of raising cattle for leather is estimated to be 17,100 liters of water per kilogram of leather [6]. The tanning process, which converts the raw hide into leather, is also extremely water-intensive and can be a major source of water pollution if not managed properly. The process involves numerous steps, including soaking, fleshing, tanning, and dyeing, all of which consume large quantities of water. A study of the leather industry in Bangladesh found that the grey water footprint of corrected leather from ovine hides was 13,735 m3/ton [7].

Care Water

Leather goods generally do not require frequent washing, which reduces their water footprint during the use phase. Cleaning is typically done with specialized leather cleaners and conditioners, which have a lower water footprint than machine washing.

End-of-Life Water

Leather is a biodegradable material, but the tanning process can affect its biodegradability. Chrome-tanned leather, which is the most common type of leather, can release chromium into the environment as it degrades. Vegetable-tanned leather is a more biodegradable alternative. Recycling leather is possible, but it is not as common as the recycling of other materials.

The Water Footprint of Down

Down, the soft layer of feathers found under the tougher exterior feathers of birds, is a lightweight and effective insulator. Its water footprint is primarily associated with the raising of ducks and geese and the processing of the down.

Production Water

The water footprint of down production is linked to the water consumed by the birds during their lifetime, as well as the water used in the processing of the feathers. The processing of down involves washing, drying, and sorting the feathers, which requires a significant amount of water. However, a life cycle assessment has shown that down has a lower environmental impact, including water consumption, compared to polyester fill materials [8].

Care Water

Down-filled products, such as jackets and duvets, do not require frequent washing. When they are washed, it is typically done in a machine with a gentle cycle and a special down-wash detergent. The water consumption during the use phase is therefore relatively low.

End-of-Life Water

Down is a natural and biodegradable material. At the end of its life, it can be composted, and it will decompose naturally. This results in a low end-of-life water footprint.

Material Comparison: A Snapshot

Frequently Asked Questions

Which material has the highest water footprint?

It is difficult to definitively name one material as having the absolute highest water footprint, as it depends heavily on the specific production methods and the boundaries of the life cycle assessment. However, conventional cotton is widely recognized for its extremely high blue water footprint due to irrigation. Materials like polyester and leather have very high grey water footprints due to pollution from manufacturing and tanning processes.

How can I reduce the water footprint of my wardrobe?

Choosing materials with a lower overall water footprint is a good start. Additionally, you can reduce the water footprint of your wardrobe by washing your clothes less frequently, using cold water, and air-drying them whenever possible. Repairing and extending the life of your garments also helps to reduce the need for new production, thereby saving water.

Is recycled polyester a better option for reducing water consumption?

Recycled polyester generally has a lower water footprint than virgin polyester because it offsets the need for new fossil fuel extraction and processing. The recycling process itself requires water, but the overall impact is typically lower than producing new polyester from scratch. However, the issue of microplastic shedding during washing remains a concern for both virgin and recycled polyester.

Learn More About Garment Care

Understanding Life Cycle Assessments

The Guide to Sustainable Fibers

Published by SELVANE Knowledge — Material intelligence for considered wardrobes.

References

[1] WWF. (2013). The Impact of a Cotton T-Shirt. [2] Water Footprint Calculator. (2017). The Hidden Water in Everyday Products. [3] Water Footprint Network. (2017). Water Footprint Assessment of polyester and viscose. [4] Lampoon Magazine. (2021). Wool industry can be circular and environmentally-friendly. [5] Chen, B., et al. (2021). Carbon Footprint and Water Footprint of Cashmere Fabrics. Fibres & Textiles in Eastern Europe. [6] C I R C U M F A U N A. (n.d.). Leather water footprint. [7] Humayra, S., et al. (2023). Water Footprint Calculation, Effluent Characteristics and Pollution Impact Assessment of Leather Industry in Bangladesh. Water. [8] International Down and Feather Bureau (IDFB). (n.d.). Life Cycle Assessment Shows Down and Feather Products Are More Sustainable Than Alternatives.