Opportunities of conjunctive use of groundwater and surface water

At the occasion of the International Symposium on Intensive Use of Groundwater: Challenges and Opportunities (SINEX; Llamas and Custodio, 2003), a roundtable was held to analyze current practices of the conjunctive use of groundwater and surface water in the world, and to discuss challenges, benefits and opportunities. The roundtable consisted of world-class groundwater specialists from 5 countries in the Americas, Europe and Asia. Selected cases of key countries, having practices and experience in the conjunctive use of surface water and groundwater resources, were presented: India, Pakistan, Spain, Mexico and Canada. The discussions included definitions and misconceptions on the practices of conjunctive use of water resources as well as technical aspects of their effectiveness and applications. Results of the discussion indicated that emphasis should be given to the integrated management of water resources, via the conjunctive use of surface water in natural or artificial basins, and aquifers. The joint assessment at the regional scale was considered the most adequate approach to effectively manage both resources. Available ad hoc tools and models are vital to the assessment and operation of conjunctive systems. Some of the main conclusions dealt with the strong political will, needed to implement such systems, and the enormous economical and environmental benefits that can be obtained.