Combining economic policy instruments with desalinisation to reduce overdraft in the Spanish Alto Guadalentín aquifer

Abstract

This paper analyses the cost-effectiveness of combining several economic policy instruments to address the problem of non-renewable pumping in the Alto Guadalentín aquifer in southeastern Spain, one of the most extreme cases of aquifer depletion in Europe. Our results show that all instruments have significant economic impacts. However, the future availability of desalinisation would notably mitigate these impacts, as farmers can substitute groundwater with desalinised water. Although a complete ban on non-renewable pumping and an environmental tax on withdrawals imply the lowest level of public expenditure, they are very unpopular and have a large political cost. The buyback of groundwater rights and the subsidisation of desalinisation in exchange for reducing withdrawals are likely to be much better received by farmers, as their cost would be charged to the public budget. A combination of instruments would split the cost of aquifer recovery between farmers and the administration and would therefore possibly not meet with as much opposition from stakeholders.

Water buybacks to recover depleted aquifers in south-east Spain

“…Under this assumption, as much as 0.65 €/m 3 per year should be paid to buy back enough water rights to eliminate unsustainable pumping rates in the aquifers. Note that, to allow comparisons, the price and cost of the buyback of rights are expressed in terms of their annual equivalent cost, not in terms of the single compensation to be paid to farmers, as in Martínez-Granados and Calatrava (2017). This cost is equivalent to the annual payment that should be given to farmers in compensation for stopping non-renewable extraction.…”

“…As in many other areas around the world, over-appropriation of water resources, weak enforcement of water rights regimes and illegal pumping from aquifers are major factors behind the depletion of groundwater resources (Marchiori, Sayre, & Simon, 2012;Skurray & Pannell, 2012). In the Segura River basin in south-eastern Spain, one of the most profitable agricultural areas in Europe, the expansion of irrigation over the last four decades has put groundwater bodies under huge pressure and caused depletion to reach alarming rates in many aquifers (Martínez-Granados & Calatrava, 2017). As in other Spanish basins, farmers and agricultural water users' associations (WUAs) have led the development of agricultural groundwater use, with very little participation or control from water authorities, which has led to the current situation of aquifer depletion (Fornés, De La Hera, & Llamas, 2005).…”

Sustainable Irrigation in Agriculture: An Analysis of Global Research

“…In addition to these two principal functions, the use of nonconventional water resources gives rise to other advantages. They provide a greater reliability in the supply, they supply higher quality water, they can generate increases in crop yields, they contribute to ensuring the stability of agricultural incomes, and they can have positive effects on seawater intrusion processes in the aquifers [65][66][67].…”

Evaluación Económica Del Aporte De Recursos Externos Para Sustituir Las Extracciones No Renovables De Los Acuíferos Del Altiplano

“…En el caso de la alternativa 2 (suministro de agua desalinizada desde la IDAM de Torrevieja), sería necesario subvencionar 0,86 de los 1,27 €/m 3 del coste total del suministro, lo que supondría un coste anual para la administración de 38,8 millones de euros. Por su parte, en el caso de la alternativa 3 (suministro de agua del ATS mediante permuta por caudales desalinizados), la subvención debería de ascender a 0,60 de los 1,00 €/mA diferencia de los resultados obtenidos por Martínez-Granados y Calatrava (2014Calatrava ( , 2017 para la zona del Guadalentín, también en la cuenca del Segura, donde la disponibilidad de agua desalinizada mitigaría el impacto negativo que la reducción de las extracciones de recursos subterráneos tendría para el sector agrario, los resultados aquí obtenidos muestran cómo eliminar las extracciones no renovables de los acuíferos del Altiplano sin proveer de recursos alternativos tendría importantes consecuencias negativas, tanto económicas como sociales, sobre el sector agrario de la zona, al verse drásticamente reducido el uso de agua. El impacto aquí estimado supondría una reducción del margen neto de las explotaciones y de la producción y el empleo agrario directo en la zona de un 48, 55 y 62% respectivamente.…”