The energy required for various processes in the water cycle can have significant economic and environmental impacts. Therefore, efficient energy management in urban water supply systems is crucial for a sustainable operation. By installing energy recovery technologies in these facilities, it is possible to reap the benefits of the infrastructure design by saving energy. In this study, a new methodology to assess the energy recovery at the inlets of district metered areas is presented, considering the city of Murcia (Spain) as case study. This methodology is based on creating a detailed model of city water supply system and calibrating such model with an experimental campaign of measurements. Then, the assessment of the hydraulic potential recovery is analysed through two different energy estimators, one considering the minimum available net head and the other assuming a variable net head. Results show that there are several points where turbines could be installed, most of them recovering in between 1000-5000 kWh, which could be used to cover the yearly energy consumption of about 24-120 m2 of a school or 10-50 traffic lights of such area. Moreover, in some points it could be recovered up to 14500 kWh. Even though these values are not high, the energy recovered could be used for self-consumption of nearby electrical loads, at the time that reduces the pressure in the system, thus leading to leak reductions. Moreover, this kind of energy recovery does not reduce the potential of other proposals for upstream energy recovery, such as replacing pressure reduction valves with turbines instead. The scripts developed to apply the proposed methodology are available in EPANET-Octave file exchange for the researcher community.

This study examined the factors that affect the private sectors\' willingness to invest in rural water supply. The study applied a mixed methods approach, including an overview of relevant studies, expert consultation, exploratory factor analysis using SPSS software, and a fuzzy-analytic hierarchy process to identify and evaluate the factors applicable to Ha Nam province in Vietnam. Some factors were distinguished that are significant to private investors\' rural water supply investment decisions, including tax incentive policy, policies to support preferred access to loans and credit, a state risk-sharing mechanism, a mechanism to adjust water price, community support, high community demand for clean water, and input water quality. In addition, the study constructed an investment attractiveness index to evaluate the attractiveness of private sector investment for two typical rural water supply projects in Ha Nam province. This index can be used as a basis for the government to design appropriate incentives to attract investment from private investors and construct an investment attractiveness map.