Bamboo and Water Use – Why the Plant Needs So Little
Short answer: Bamboo gets by on rainfall alone in most growing regions and rarely needs irrigation. That is the main difference from cotton, which has to be watered in many regions. But the water used in producing the fabric is another story, and it counts too.
Why the plant manages
Bamboo has a dense, shallow root network that captures rainwater efficiently, and the plant grows in climates with plenty of rainfall. Water therefore rarely has to be led out onto the fields, the way it does for many other crops.
The difference from cotton
Cotton is often grown in dry regions, where the crop has to be watered throughout the season. That is where the large water figures in textiles come from, and it is also why the comparison between the two plants falls out as it does.
The root network stays in the ground
Because bamboo is harvested by cutting the stem, the root network stays in the ground and holds moisture. The soil does not lie bare between harvests, which reduces both evaporation and the need to water the new shoots along.
Where the water is used instead
The water in a finished fabric is used mostly in the factory. The cellulose has to be dissolved, rinsed and spun, and the fabric has to be dyed. Those are the steps that use most water, and they depend on the factory rather than the plant.
Dyeing
Dyeing is typically the most water intensive single step in making a garment. A darkly dyed garment uses more than an undyed one, and that applies whether the fibre comes from bamboo, from wood or from cotton.
Closed loops
Some factories recover the water and the solvents in a closed system. That is especially the case with lyocell, where the process is built for it. With classic viscose it is less common, and that is a real difference between the two processes.
What you can look for
You can look at which process the fibre was made with and whether the production is certified. Both are on the item's page, where the material composition is listed too, and that information can be compared across brands.
What you use yourself
Water at home counts as well. A half load uses almost as much water as a full one, so it makes a difference to wash full loads at 30 degrees rather than half loads at 40.
The figures you meet
Many figures circulate for water use per T-shirt, and they rest on different methods of counting. Some include rainfall, others only water actively supplied, so two figures for the same garment can be far apart.
See the range
The material composition is listed on every item under bamboo underwear for women, bamboo underwear for men and bamboo bedding, and those figures can be compared rather than words on a front. See also the honest guide to bamboo and the environment and washing guide.
Frequently asked questions
Does bamboo need less water than cotton?
As a plant, yes. Bamboo usually manages on rainfall, where cotton in many regions has to be watered all season.
Where is the water used instead?
Mostly in the factory, to dissolve and rinse the cellulose and to dye the fabric. Dyeing is the most water intensive single step.
Can I do anything myself?
Wash full loads at 30 degrees. A half load uses almost as much water as a full one does.
You can find the full range at Bamboo-Clothing.com.
