Rainwater harvesting is an ancient practice currently used for flood and drought risk mitigation. It is a well-known solution with different levels of advanced technology associated with it. This study is aimed at reviewing the state of the art with regards to rainwater harvesting, treatment, and management. It focuses on the environmental and social benefits of rainwater harvesting and links them to the Sustainable Development Goals. The review identifies characteristics of laws and regulations that encourage this practice and their current limitations. It presents methodologies to design a rainwater harvesting system, describes the influence of design variables, and the impact of temporal and spatial scales on the system’s performance. The manuscript also analyzes the most advanced technologies for rainwater treatment, providing insights into various processes by discussing diverse physiochemical and biological technology options that are in the early stages of development. Finally, it introduces trends and perspectives which serve to increase rainwater harvesting, water reuse, and effective management.

Permeable pavements have been used widely across the world to manage urban stormwater. The hydrological behaviour of permeable surfaces is a complex process affected by many factors, such as rainfall intensity, rainfall duration, pavement geometrical conditions, and clogging level of the permeable surface, amongst others. This laboratory study was carried out to assess the influence of clogging level and rainfall intensity on the infiltration capacity of porous mixture surfaces used in Permeable Pavement Systems (PPS). Porous Concrete (PC) and Porous Asphalt (PA) mixtures with different air void contents (15%, 20%, and 25%) were subject to different clogging scenarios by using varying sediment loads (0, 500, and 1000 g/m²). Permeability experiments were carried out for each clogging scenario through a new rainfall simulator specially developed, tailored, and calibrated for the laboratory simulation of a wide range of rainfall events. Permeability measurements were taken under all different scenarios as a result of the combination of the different rainfall events (50, 100, and 150 mm/h) simulated over the specimens of porous mixtures and the sediment loads applied to them. The results showed that the PC mixtures tested perform better than the PA ones in terms of infiltration capacity, showing less potential for clogging and being more easily cleaned by the wash-off produced by the simulated rainfall events.

In this work, a novel methodology is presented to identify isolated DMAs (District Metered Areas) in a water distribution network having a large number of water sources, such as autonomous reservoirs, directly connected to the distribution network. The method proposed is based on graph theory. Initially, the network is subdivided to the least terms into elementary districts, areas of influence of each supply source. In a second step, the resulting elementary areas are conveniently coupled to form possible layouts of isolated DMAs solutions. The union process takes into account the size of districts and the overall network resilience. The method is effectively applied to a case study derived from a large real water distribution network.

Green roofs are emerging as an increasingly popular Sustainable Urban Drainage Systems (SUDS) technique for urban stormwater management. Indeed, they allow a significant reduction of peak flows and runoff volumes collected by drainage system, with consequent reduction of flooding events and pollution masses discharges by CSO. To estimate the imperviousness of a green roof and to evaluate its hydrological impact within an urban watershed, a bucket model was developed to simulate a rainfall-runoff relationship for a single green roof. The objective is modeling hydrological fluxes in relation to climate forcing, basic technology components and geometric characteristics of green roof systems