503
a global market, and fossil-fuel based power generation by a regional power provider. Efficiency across multiple sectors by multiple players rather than the productivity of isolated firms is, however, a necessity for the long-term sustainability of all
three systems in the context of resource scarcity, increasing population pressure,
and other stressors, as described throughout this book.
Examples of integrated urban FEW systems include:
• waste reclamation (i.e., recovering energy from food waste and wastewater, and
recycling wastewater and greywater for irrigation in a closed supply loop);
• biomass-based energy (i.e., converting residues and waste to energy); and
• large-scale water infrastructure projects such as multi-use water reservoirs for
energy generation, irrigation, and cooling water.
Separate systems may have advantages, including less intensive planning and
coordination (lighter infrastructure), lower initial capital expenditures, public familiarity, associated economic and political structures (the policy criterion), and wellestablished existing support infrastructure.
Integrated systems may have advantages including: less resource extraction and
associated environmental impacts and costs (such as when waste streams from one
sector are used as resources for another sector), resource security (availability,
safety, and affordability) in the case of scarce or diminishing resources, local job
creation, and micro-scale practices such as green roofs and rain gardens have relatively low barriers to entry which may encourage broad adoption.
The challenges for implementing integrated systems may need to be addressed
using a variety of approaches. For example, comprehensive data-based assessments
may be necessary to evaluate potential benefits and risks and resolve stakeholder
concerns about transitions from separated to integrated systems (such as for recycled water in garden irrigation, which could introduce pollutants such as heavy metals, pathogens, and chemicals of emerging concern into soils and food chains).
Government, private enterprises, and civil society may need to engage more fully in
theorizing and developing the political frameworks to achieve multiple sustainable
development goals while minimizing the risks of adverse cross-sectoral impacts
(policy heavy). Successful micro-scale pilot projects may need to be implemented
widely before proof-of-concept and market forces can drive broad implementation.
Examples of integrative practices that started as pilot projects and are now more
widely accepted include green roofs, which provide potential synergies in the FEW
nexus by improving energy efficiency for buildings, reducing stormwater runoff and
associated pollution, and capturing rainwater for potential reuse, while potentially
supporting food production and/ or recreation (a lighter footprint). Similar to green
roofs, rain gardens can be used to direct rainwater for urban food production and
stormwater management, reducing the energy consumption required for both irrigation and water treatment. Waste-to-resource practices convert municipal and/or food
waste to energy, fertilizer, and reclaimed water that can be used to supply other portions of the FEW nexus in cities.
When these separate actions take place within a broader vision for integrated
management and governance across FEW sectors, systems and scales may organically
18 Cities at the Nexus
a global market, and fossil-fuel based power generation by a regional power provider. Efficiency across multiple sectors by multiple players rather than the productivity of isolated firms is, however, a necessity for the long-term sustainability of all
three systems in the context of resource scarcity, increasing population pressure,
and other stressors, as described throughout this book.
Examples of integrated urban FEW systems include:
• waste reclamation (i.e., recovering energy from food waste and wastewater, and
recycling wastewater and greywater for irrigation in a closed supply loop);
• biomass-based energy (i.e., converting residues and waste to energy); and
• large-scale water infrastructure projects such as multi-use water reservoirs for
energy generation, irrigation, and cooling water.
Separate systems may have advantages, including less intensive planning and
coordination (lighter infrastructure), lower initial capital expenditures, public familiarity, associated economic and political structures (the policy criterion), and wellestablished existing support infrastructure.
Integrated systems may have advantages including: less resource extraction and
associated environmental impacts and costs (such as when waste streams from one
sector are used as resources for another sector), resource security (availability,
safety, and affordability) in the case of scarce or diminishing resources, local job
creation, and micro-scale practices such as green roofs and rain gardens have relatively low barriers to entry which may encourage broad adoption.
The challenges for implementing integrated systems may need to be addressed
using a variety of approaches. For example, comprehensive data-based assessments
may be necessary to evaluate potential benefits and risks and resolve stakeholder
concerns about transitions from separated to integrated systems (such as for recycled water in garden irrigation, which could introduce pollutants such as heavy metals, pathogens, and chemicals of emerging concern into soils and food chains).
Government, private enterprises, and civil society may need to engage more fully in
theorizing and developing the political frameworks to achieve multiple sustainable
development goals while minimizing the risks of adverse cross-sectoral impacts
(policy heavy). Successful micro-scale pilot projects may need to be implemented
widely before proof-of-concept and market forces can drive broad implementation.
Examples of integrative practices that started as pilot projects and are now more
widely accepted include green roofs, which provide potential synergies in the FEW
nexus by improving energy efficiency for buildings, reducing stormwater runoff and
associated pollution, and capturing rainwater for potential reuse, while potentially
supporting food production and/ or recreation (a lighter footprint). Similar to green
roofs, rain gardens can be used to direct rainwater for urban food production and
stormwater management, reducing the energy consumption required for both irrigation and water treatment. Waste-to-resource practices convert municipal and/or food
waste to energy, fertilizer, and reclaimed water that can be used to supply other portions of the FEW nexus in cities.
When these separate actions take place within a broader vision for integrated
management and governance across FEW sectors, systems and scales may organically
18 Cities at the Nexus