Supply Reliability Associated with Rainwater Harvesting Designs in Peri-Urban Households

Abstract

The rapid expansion of peri urban areas globally has placed unprecedented stress on centralized municipal water supply systems, necessitating decentralized alternatives to ensure domestic water security. Among various decentralized strategies, rainwater harvesting has emerged as a structurally viable and environmentally sustainable intervention. However, the theoretical modeling of rainwater harvesting systems frequently overestimates their practical supply reliability, primarily due to the lack of robust empirical data derived from prolonged field evaluations. This paper provides a comprehensive assessment of supply reliability by analyzing field evaluation evidence gathered from rainwater harvesting designs implemented in peri urban households. Through an extensive monitoring framework, the study evaluates the volumetric and temporal reliability of varying catchment and storage configurations over consecutive seasonal cycles. The findings indicate that while standard rainwater harvesting designs significantly alleviate primary water demand, actual supply reliability is highly contingent on localized rainfall patterns, system sizing, and household extraction behaviors. Discrepancies between designed capacity and field performance underscore the necessity for adaptive design frameworks that account for climatic variability and user dynamics. The evaluation concludes that enhancing the reliability of decentralized water systems requires a paradigm shift from static engineering models to dynamic, behaviorally informed design parameters, thereby ensuring long term sustainability in water stressed peri urban environments.