2,000 to 5,000 liters of water per day to ''feed'' one person

The water footprint includes blue water or fresh water from rivers, lakes or aquifers. PHOTO:

Maite Martínez Aldaya, PhD in Ecology from the University of Navarra and advisor to the United Nations Environment Programme, gave a talk on the water footprint - the amount of water that humans consume and pollute through their activities - at the Science Library building.

The expert, a graduate in Biology and former student of the Master's Degree in Biodiversity, Landscapes and Sustainable management of the School of Sciences, stated that, according to the UN, the daily diet of a person means a expense of between 2,000 and 5,000 liters of water, since most of the consumption is taken by agricultural activity, which involves 84% of the consumption of green and blue water in Spain.

The water footprint," she explained, "includes green water, or rainwater that accumulates in the ground; blue water, fresh water from rivers, lakes and aquifers; and gray water, or water polluted by man". In this sense, the expert continues, "in Spain we have a water footprint per capita and per year of 2,461 m3. Of this, 338 m3 correspond to gray water, 321 to blue water and 1,802 to green water".

For this reason, he felt that water saving plans should not be directed so much at household consumption as at reducing expense in agriculture:"It is important to save water in households. However, we can have a greater impact if we look at our consumption patterns, lifestyles and the goods we consume. To use water more rationally we need to invest in Education and awareness."

In the talk, which was given as part of the Master's Degree in Biodiversity, Landscapes and Sustainable management of the academic center, the specialist advanced the implication of the water footprint in the national hydrological plans and in the EU Water Directive framework .