Resilient Water Management Strategies in Urban Settings

In this chapter, we draw attention to urban cities’ building water systems management strategies, focusing on both sustainability and resilience of water and energy resources. Rainwater harvesting and graywater recycling have long been identified as alternative water sources for the sustainable management of water resources. We present a conceptual framework for a Decentralized Green Water-Infrastructure System (DGWIS) for large buildings (industrial, commercial, government, and office) that integrates locally available water sources (rainwater and graywater) with renewable local energy sources (solar and wind) to support water treatment and distribution. The optimization framework for DGWIS introduced in this chapter will quantify the energy and water potentially saved. DGWIS can function as a standalone infrastructure element and could also be an attractive option for high density population urban areas where water scarcity is a serious issue, particularly for large buildings such as shopping centers, high-rise buildings, hotels and dormitories.

Japan has been developing non-potable water reuse systems mainly for urban applications such as toilet flushing, urban stream water augmentation, and landscape irrigation. Recently in Japan, reclaimed water has attracted attention not only as water resource but also a heat and energy source. Because sewage temperature is more stable than atmospheric temperature, the efficiency of heat pump systems improves when reclaimed water is used for the heat source/sink than when air is used for. In addition, a cogeneration system applying a biogas power generator is considered as an effective option that can produce electricity and heat energy from food waste and excessive sludge of biological treatment processes. Two commercial buildings in Osaka have installed advanced environmental technologies such as an onsite water reclamation system, a biogas power generation system, and a heat recovering system from reclaimed water. By using reclaimed water as water resource, as well as heat and energy source, these buildings can successfully save the amount of tap water and energy consumption required for hot water supply and heating and cooling systems in the facilities. This chapter describes the two case study projects in Osaka.

This chapter introduces selected cases of integrated water resource management practices focusing on smart decentralized water systems in South Korea, where industry/government bodies have made significant progress in smart water use. SDWM (Smart Decentralized Water Management) connects multiple alternative water resources within individual buildings and continuously balances their utilization to enhance self-efficiency and build resilience. It also supports more efficient water supply portfolio/transfer/trade within district water networks. We expect that SDWM will play an important role in augmenting the efficiency of integrated water management planning and operation through closer interactions among stakeholders and informed decision-making at all levels.

Water infrastructure systems management is one of the most urgent global issues, as urbanization and population continue to rise. Monitoring and analysis of water demand is one of many challenges faced by researchers in the past decades. The spread of smart technology improves the way in which data can be collected. Water utilities are starting to try out innovative smart meters instead of traditional water meters to read water consumption with a high-resolution rate. This new trend made available a great amount of data opened new opportunities to improve water services and fostered the interest in understanding the use of water in domestic environments along with direct implications on identifying demand patterns, forecasting future demands, detecting leakage, improving users’ awareness, and customizing users’ profiles. This chapter presents a pilot study site of water end-use demand monitoring in a residential apartment located in Naples (Italy). A monitoring system based on Internet of Things (IoT) technology was implemented and installed on the fixtures of a single-family apartment. Data gathered have been used to realize an open dataset available in the research community to train data-driven algorithms. Overall, the chapter provides insights for new perspectives and further research related to the importance of high-resolution data to improve water demand-side management. This case study represents a first step towards a decentralized monitoring water system aimed to increase user awareness to promote water conservation.

Water is a defining issue of our time. Water and sanitation systems are stressed as infrastructure systems are aging, climate and weather patterns are changing, and populations are moving and rapidly growing. The ability to provide reliable, safe water and sanitation services is becoming increasingly difficult for communities across the world. This chapter focuses on localized solutions to treating water onsite for reuse on a small scale. Utilities can enable and allow decentralized, neighborhood-scale water treatment systems by creating shared responsibility and ownership of managing water resources within the community. This chapter highlights numerous examples from around the world, projects and lessons learned so that they may share proof of concepts to encourage transformation. Looking to the future, opportunities exist for localized systems to not only produce non-potable water, but become vehicles for resource recovery, tapping into the potential for thermal heat, nutrient and biosolids recovery, as well as a potential source of drinking water.

The Bullitt Center (Seattle, Washington) was the first office building in the world to fully meet the rigorous requirements of the Living Building Challenge. This chapter discusses the design of the building’s potable water, graywater and blackwater treatment systems. It also reviews the treatment performance of these systems for the first eight years of operation. The chapter discusses capital, operation and maintenance costs and offers lessons-learned that may assist owners and designers of future sustainable building projects.

Urban water reuse represents a viable and successful water management strategy to secure additional supply in places prone to drought or water scarcity. Many communities already recycle wastewater to supplement non-potable and potable water supply. This chapter outlines the drivers and barriers for water reuse as a water management strategy. It examines water reuse issues in the state of Oklahoma, USA, a drought-prone region with no precedent of potable reuse, to discuss how water reuse projects occur and what determines their success. Despite its technological and environmental advantages, the success of municipal wastewater reuse is often dependent on public perception and willingness to use recycled water. Psychological reactions of disgust create the primary barrier to this success. Some research has shown that community education initiatives can decrease disgust and increase willingness to support water reuse projects. This chapter cites a community education effort in Norman, OK that demonstrated the ability of in-person education to reduce disgust and increase support for urban water reuse projects.

Urban Agriculture is becoming more prevalent across the world because of its ability to provide healthy and nutritious food for urban populations and contribute to urban ecosystem services. Generally, potable water is the main source of irrigation for urban agriculture, and in many regions, this negatively impacts ecosystem services because of the energy required to transport and treat potable water. Rainwater harvesting is a decentralized water strategy and urban agriculture is a decentralized food production method. This chapter reviews the literature on rainwater harvesting for urban agriculture, two decentralized strategies promoting urban sustainability. Four case studies in the Unites States (two are in wet regions and two are in semi-arid regions) are used to analyze rainwater harvesting’s ability to irrigate urban agriculture, save energy, and reduce greenhouse gas emissions. Study results show that location does matter because rainfall directly affects the ability for cities in semi-arid regions to harvest rainfall for irrigation. A significant difference is apparent in rainwater availability between arid and wet regions of the US because of the significantly lower amount of precipitation in arid regions, as well as the number of days in arid regions where there is insufficient rainfall to produce runoff.

Results also demonstrate that, even in arid regions, rainwater harvesting has the potential to lower potable water use, save energy, and reduce greenhouse gas emissions.

The 2004 tsunami impacted coastal India resulting in thousands of mortalities and hundreds of thousands displaced. The aftermath elicited the largest reconstruction effort in India’s history. This study investigates reconstruction in the adjacent territories of Nagapattinam District (Tamil Nadu) and Karaikal District (Puducherry). While both territories deployed virtually identical public–private partnership frameworks consisting of Memoranda of Understandings between the governments and humanitarian organizations, the models deployed to manage reconstruction differed. In Nagapattinam, a collaborative model was executed in which various public agencies were responsible for their respective reconstruction activities. Meanwhile, Karaikal exercised a single agency model under which a standalone public agency assumed responsibility for reconstruction activities. By linking primary data to the theoretical literature, this study examines outcomes of the two governance models through the lens of water. In this case, findings suggest that the collaborative approach—while seemingly more holistic and participatory—produced inferior outcomes due to issues of coordination, bureaucratic layering, and project organization. This outcome, which is incongruent with many theories on governance, development, and project management, is problematized and discussed as are strategies to better integrate the water sector into disaster and urban planning.