Manejo sustentable del uso de agua y crecimiento urbano

Municipal water utilities face a complex set of environmental, economic, technical and administrative challenges, among others. In Northern Mexico, urban growth in the face of scarce water resources poses a serious sustainability problem. Water demand and supply management in that context could contribute towards improving the balance between extraction and recharge in the water sources exploited by municipal water systems, and thereby the sustainability of municipal water use. This paper evaluates the potential in that respect of two specific management tools: the cost of water for users (for demand control) and the physical efficiency of conveyance and distribution infrastructures (to control the balance between extraction and use). For that purpose, it is established the relationship between population, water use, physical efficiency, administrative efficiency and extraction requirement in a municipal water system; develop a long term extraction requirement forecast procedure that takes into account distinct scenarios with respect to the application of the aforementioned management tools; and, specify these scenarios based on the analysis of technical and financial data from municipal water utilities. It is presented a case study for the Laguna Metropolitan Area however the methodology could be applied to any other region. The results, combined with relevant hydrological information for the case study region, suggest that the application of the management tools could have a significant impact on municipal extraction requirements; however, this would be insufficient in and of itself to attain sustainability. For that, an integrated water resources management approach that considers simultaneously all types of water uses would be necessary.