Evaluation of water footprint of urban renewal projects. Case study in Seville, Andalusia.

ABSTRACT

This publication presents a methodology for the evaluation of the water footprint of urban renewal projects. The indirect water footprint is obtained by adding together the embodied or virtual water of the materials incorporated in the 12-month project, while the direct footprint is mainly due to the green areas and rainwater collection system over its 40-year life span. The methodology, originally defined for the agricultural sector, is adapted to an urban system that includes gardens and sustainable urban drainage systems. In an innovative way, the present work analyses the amortisation of the indirect water footprint of the construction products by improvements in the city water cycle. The project involves street renewal with water-sensitive criteria, with five green areas, and road and pavement construction. The methodology identifies changes in garden designs, soil drainage, and rainwater-collecting systems in terms of blue, green, and grey water footprints. Five scenarios of a project in Seville, Spain are studied. The indirect water footprint of the project is 2.6 times higher than that in a standard project, but, due to annual savings of 65% in its direct water footprint, the breakeven point is reached in the 10th year.