Environmental Impacts of Rainwater Harvesting Systems in Urban Areas Applying Life Cycle Assessment—LCA

Abstract

Climate change poses a series of challenges to water management to satisfy society’s current and future needs. Considering water an essential resource for life, this research is dedicated to comparing the environmental impacts caused by the conventional water supply system and Conventional Water Supply system complemented with rainwater harvesting, considering in the first one not only the components of the municipal public supply, but also the hydraulic components of the residences until the point of use. A life cycle assessment—LCA—was conducted for the two systems, considering them from the catchment to the point of use. This methodology quantifies environmental impacts throughout the product or process life cycle to obtain sustainable options, from raw material extraction to ultimate disposal. The results expose that the hybrid system represents an increase in environmental impacts. However, at a building scale, this increase was very small, and this can be seen as favorable to the hybrid system due to the benefit it brings. The seven percent reduction in water demand over the conventional system can represent significant relief in regions that already have water stress as a reality. This study has the potential to guide managers and designers of public water policies, providing data for a better decision-making process.

Keywords

• rainwater harvesting systems
• life cycle assessment
• environmental impacts
• water management
• climate change