The truth about water use

2010-08-13 20:07

Cape Town - How much water does it take to produce one cotton T-shirt?

The answer, according to Water Neutral founder Pancho Ndebele, is a lot more than you might think.

Writing in the latest edition of The Environmental Handbook: A Guide to Green Business in South Africa, launched in Cape Town this week, he says producing one kilogram of cotton textile requires an average of 11 000 litres of water.

"In other words, a cotton T-shirt, with a weight of 250g, carries a price tag of 2 700 litres of embedded water.

"Of this total volume, 45% is irrigation water consumed by the cotton plant; 41% is rainwater evaporated from the cotton field during the growing period; and 14% is water required to dilute the wastewater flows that result from the use of fertilisers in the field and the use of chemicals in the textile industry."

Ndebele says global annual cotton production evaporates 210 billion cubic metres of water and pollutes another 50 billion cubic metres.

He suggests that in the near future, labelling that indicates the "virtual" water in a product may soon become a regulatory requirement.

"The reality is that water footprinting is becoming as important as measuring energy use and greenhouse gas emissions."

Ndebele defines the water footprint of a business as the volume of freshwater that is used both directly and indirectly to run and support that business.