Economic Assessment of Opportunities for Managed Aquifer Recharge Techniques in Spain Using an Advanced Geographic Information System (GIS)

Abstract

This paper investigates the economic aspects of Managed Aquifer Recharge (MAR) techniques considered in the DINA-MAR (Depth Investigation of New Areas for Managed Aquifer Recharge in Spain) project. This project firstly identified the areas with potential for MAR for the whole of the Iberian Peninsula and Balearic Islands of Spain using characteristics derived from 23 GIS layers of physiographic features, spanning geology, topography, land use, water sources and including existing MAR sites. The work involved evaluations for 24 different types (techniques) of MAR projects, over this whole area accounting for the physiographic features that favor each technique. The scores for each feature for each type of technique were set based on practical considerations and scores were accumulated for each location. A weighting was assigned to each feature by "training" the integrated score for each technique across all the features with the existing MAR sites overlay, so that opportunities for each technique could be more reliably predicted. It was found that there were opportunities for MAR for 16% of the area evaluated and that the additional storage capacity of aquifers in these areas was more than 2.5 times the total storage capacity of all existing surface water dams in Spain. The second part of this work, which is considered internationally unique, was to use this GIS methodology to evaluate the economics of the various MAR techniques across the region. This involved determining an economic index related to key physiographic features and applying this as an additional GIS overlay. Again this was trained by use of economic information for each of the existing MAR sites for which economic data and supply or storage volume were available. Two simpler methods were also used for comparison. Finally, the mean costs of MAR facilities and construction projects were determined based on the origin of the water. Maps of potential sites for Managed Aquifer Recharge (or "MAR zones") in the Iberian Peninsula and Balearic Islands of Spain and the results of the previous economic studies developed at the beginning of the project were used as the foundation for the economic analysis. Based on these data, a new specific mapping of the total expected costs for all "MAR zones" ([euro]/m3) was proposed based on the techniques that were considered most appropriate for each Spanish study case. Capital costs ranged from Euro 0.08-0.58 per m3/year. Overall, this study investigates the opportunity and economic feasibility of implementing new MAR projects and provides support to decision makers in Spain. The novel mapping provides valuable guidance for the future development of Managed Aquifer Recharge projects for water managers and practitioners.