A procedure to analyze the viability of rainwater harvesting systems in urban areas based on pre-defined diagrams

Procedimento para análise da viabilidade de implantação de sistemas de aproveitamento de águas pluviais em centros urbanos por meio de diagramas de pré-dimensionamento

ABSTRACT

Giving some specific precipitation regimes and technical design parameters, urban Rainwater Harvesting Systems (RWHS) may represent an alternative source to drinking water supply system promoting its conservation and rational use. The use of RWHS requires the definition of generic and simplified method for sizing RWHS accumulation tanks, which is has being considered the most expensive component of the system. Additionally, several methods have being used to define reservoir volumes leading to a wide variety of final reservoir volumes many of them over estimated. The main objective of this article is to present a new methodology to define RWHS reservoir volumes considering technical and economic viabilities of the systems. The proposed methodology was incorporated into a Decision Support System (DSS), named SARA. The method provides an alternative way to define smaller RWHS reservoir volumes once it accepts lower levels of reliabilities giving that the RWHS is considered a complimentary system, better suited for urban areas. RWHS design diagrams are built as a result of the methodology in an attempt to offer a tool to initial and rapid design of reservoir volumes for RWSH. The method was applied to different urban areas in Brazil.

Keywords:
Rational water use; Rainwater harvesting systems; Decision support system