ABSTRACT
Many companies, especially large multinationals, make/sell hundreds or even thousands of product lines. Given the fundamental role of water in their operations and supply chains, it is not surprising that large businesses in the food and beverages sector were the first to explore the potential for Water Footprint Assessment to aid understanding of company-wide risks. Water Footprints of national consumption have been mostly calculated using what are called ‘bottom-up’ methods. These methods use the total consumption volumes of individual product, goods and services by the inhabitants of the country and the Water Footprint of producing these products estimated based on their origin. Some work has used ‘top-down’ approaches which first calculate the total Water Footprint of national production and then use Multi-regional Input–Output tables to trace the difference between production and consumption in an economy. Multi-regional Input–Output tables are in development and are available for limited sectors of economy only, so at present this approach has limited utility.
