Enviro-Technical Assessment of Social Responses to Water Demand Management Policies Facing Water Scarcity

Abstract

Because cities are particularly vulnerable to freshwater scarcity, optimal water usage is critical for urban resilience, addressing health concerns, and meeting basic human needs, particularly in water-scarce regions. However, any water management measure applied in urban settings can influence key stakeholders and, even more broadly, water infrastructure like the urban water distribution networks (UWDNs). Given the severe and ongoing water scarcity, Iranian water utilities have recently implemented a policy called “Limiting Water Access using Pressure Management” (LWAPM). With direct and indirect implications across various aspects, this strategy involves reducing water pressure even lower than the minimum required level in the UWDNs, compelling households to purchase and install residential pump and tank systems. Such a social response results in making a complex triple feedback loop encompassing technical, social, and environmental dimensions. Hence, an enviro-technical assessment was carried out by introducing a creative methodological approach to comprehensively examine the direct and indirect mutual effects of applying the LWAPM policy through hydraulic simulation and life cycle thinking. The scope of this research incorporated the whole of the urban water system, including the UWDN, urban water supply system (UWSS), and residential water network (RWN). The study highlighted that introducing residential pump and tank systems into a given UWDN in Iran, Isfahan Province, led to substantial environmental consequences. In the short term (1 year), implementing the LWAPM policy led to endpoint environmental impacts that were double those seen when the policy was not in place. However, over a longer period (19 years), the impact was reduced, exhibiting only a 1.4 times increase relative to the baseline levels before the policy’s implementation. Furthermore, the findings revealed that the residential pump and tank systems effectively distributed pressure across floors and alleviated water shortages in residential units, particularly on higher floors of buildings.