Advantages of integrated and sustainability based assessment for metabolism based strategic planning of urban water systems

Abstract

Despite providing water-related services as the primary purpose of urban water system (UWS), all relevant activities require capital investments and operational expenditures, consume resources (e.g. materials and chemicals), and may increase negative environmental impacts (e.g. contaminant discharge, emissions to water and air). Performance assessment of such a metabolic system may require developing a holistic approach which encompasses various system elements and criteria. This paper analyses the impact of integration of UWS components on the metabolism based performance assessment for future planning using a number of intervention strategies. It also explores the importance of sustainability based criteria in the assessment of long-term planning. Two assessment approaches analysed here are: (1) planning for only water supply system (WSS) as a part of the UWS and (2) planning for an integrated UWS including potable water, stormwater, wastewater and water recycling. WaterMet(2) model is used to simulate metabolic type processes in the UWS and calculate quantitative performance indicators. The analysis is demonstrated on the problem of strategic level planning of a real-world UWS to where optional intervention strategies are applied. The resulting performance is assessed using the multiple criteria of both conventional and sustainability type; and optional intervention strategies are then ranked using the Compromise Programming method. The results obtained show that the high ranked intervention strategies in the integrated UWS are those supporting both water supply and stormwater/wastewater subsystems (e.g. rainwater harvesting and greywater recycling schemes) whilst these strategies are ranked low in the WSS and those targeting improvement of water supply components only (e.g. rehabilitation of clean water pipes and addition of new water resources) are preferred instead. Results also demonstrate that both conventional and sustainability type performance indicators are necessary for strategic planning in the UWS.

Expanding the Distributed Generation Concept: Toward Decentralized Energy and Water Supply

“…Almost two decades later, reporting several successful case studies in the country, the director of Malaysia's hydraulic research institute emphasized how incorporation of rainwater harvesting systems in a housing area including commercial and public buildings made possible to achieve a 50% reduction of the peak discharge, calling for a comprehensive vision for which rainwater utilization should not be restricted to supplementing water supply to reduce the water bill, but also related to other aspects of living like food, water and energy security, flood mitigation, and environmental rehabilitation. Rainwater harvesting, indeed, reduces the (i) threat of local flooding, (ii) need for clean water in water distribution system, (iii) pollution of freshwater bodies via stormwater runoff, and (iv) energy and chemicals demand for wastewater treatment …”

“…Rainwater harvesting, indeed, reduces the (i) threat of local flooding, (ii) need for clean water in water distribution system, (iii) pollution of freshwater bodies via stormwater runoff, and (iv) energy and chemicals demand for wastewater treatment. [46] Similarly, reporting the case of the wealthy Sant Cugat del Vallès Spain's city (56 000 inhabitants with very high individual water consumption rate) which pioneered the promotion of rainwater harvesting in residential buildings since 2002, scholars in Spain recently reported very high public acceptance and user satisfaction for water harvesting thanks to the high quality of the harvested rainwater due to integrated water treatment (filter, first flush diversion, and disinfection membranes). [47] In general, government investment in distributed energy generation via today's low-cost solar PV and solar thermal systems is more beneficial than investing in expanding centralized energy generation.…”

Mitigation Options for Future Water Scarcity: A Case Study in Santa Cruz Island (Galapagos Archipelago)

“…Also, the aspects of modelling the water cycle in the UWS, as different and separate components made it appropriate for this case study, since there is no sewage system and only the supply and demand component could be modelled. Moreover, it concurrently forecasted water demand under various scenarios and evaluated the performance of several strategic solutions for a water supply problem [23]. Also, this model is able to represent the daily, seasonal, and annual (future) dynamics of the water demand (i.e., caused by demography or changes in consumption pattern).…”

Solar Energy Block-Based Residential Construction for Rural Areas in the West of China

“…The treated rainwater is stored in a water tank, which is built on the foundation block, and can be reused for gardens, livestock, irrigation, and domestic use. Application of rainwater harvesting in the block-based construction system provides a substantial benefit and sustainable outcomes for both water supply and wastewater subsystems by relieving the pressure of clean water distribution [29].…”