More cash and jobs per illegal drop? The legal and illegal water footprint of the Western Mancha Aquifer (Spain)

In many situations, the overuse of natural resources is aggravated by illegal use. More insights on the drivers and significance of this phenomenon are needed in order to formulate policies that can effectively ease human pressure on the environment. This paper makes use of the water footprint (WF), as a physical indicator of freshwater use, and introduces both economic (water productivity) and social (labour intensity) indicators to understand illegal groundwater use from a multiple perspective. Using data from the year 2000 and from 2007 to 2009, we analyse in detail the case of the Western Mancha Aquifer, in central Spain, where legal and illegal groundwater use take place simultaneously. Results show that nearly 52% of the agricultural blue WF is linked to illegal groundwater use, mostly for vine and vegetable irrigation. Besides this, the illegal share accounts for around 56% and 57% respectively of the gross income and employment generated by irrigation in the area. Therefore, although action to halt illegal withdrawals is a recurrent call to ease pressure on natural resources and ecosystems, these figures reflect the economic and social drivers, which might explain why such action is difficult to implement. In addition, the data presented in this paper provides new insights into some aspects of a public plan recently implemented to regularize illegal use by purchasing and reallocating groundwater rights on the basis of social and environmental grounds, which might be relevant for future public policy measures in situations presenting both over-allocation of water rights and illegal water use.