Managing the risks of stormwater through rainwater harvesting systems and rain gardens: A global perspective

Abstract

This study investigates the sustainable role of rainwater harvesting (RWH) systems and rain gardens (RG) in stormwater management based on worldwide perspectives by using both quantitative and qualitative data. The research relied on a questionnaire-based survey. Domain experts on water management from 38 different countries with different levels of annual precipitation rates and income (GDP per capita), contributed to the survey. Statistical analysis, including reliability analysis, normality test, and, Kruskal-Wallis test were performed for the quantitative data. The qualitative part of the survey was analysed through content analysis software, QDA Miner Late v3.0. The study showed that rainwater harvesting technologies and rain gardens are not adequately valued for mitigating stormwater risks, although proper implementation of RWH technologies and optimum use of RG promise several contributions, such as better water infiltration into the soil, decreased groundwater contamination, increased vegetation, proper level of soil moisture and hindered surface runoff. It was also observed that countries' annual precipitation rates and income levels directly impact higher awareness and current sustainable implementations. However, the perception of the flood as a crucial danger was determined as highest in countries with moderate annual precipitation rates. The importance of public engagement through policy-makers and local authorities was highlighted by promoting Nature-based solutions, pilot projects, incentives, and altering design criteria on newly constructed buildings to boost the use of RWH technologies and RG as a cheaper, accessible, and sustainable solution for stormwater management.