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(Gleick, 2010, Brekke et al., 2009). Yields of existing systems can also be increased by ad-
justing operation rules (e.g., in the Pacific Northwest, Vano et al., 2010) and by the use of
seasonal and short-term climate and weather forecasting. Daigger (2008, 2009) presents
a view of the future urban water supply system that would be very useful for adapta-
tion. He advocates for closed-loop urban water systems to meet urban sustainability
goals that not only result in less water being removed from the natural system, but also
result in energy and nutrient recovery. Recycled water, reclaimed wastewater, and rain-
water harvesting can be used irrigation needs with potable needs met from outside the
area or local sources. Energy use is decreased by the decentralized nature of these types
of sources and recovery of heat and organic mater from wastewater. Nutrients are also
recovered from wastewater. Improved water management is also obtained by separat-
ing waste streams into gray water, black water (feces) and yellow water (urine). The
concept is that graywater would used locally while the other wastewater streams are
would be treated in centralized facilities, although assuring the separation of graywater
systems and potable water systems in the home remains problematic. Source separa-
tion also reduces wastewater treatment capacities and energy used (due to high-energy
requirements, desalination should not be viewed as a sustainable water source). Such a
system also provides benefits in terms of a reduced urban heat island effect, use of less
energy, and improved aesthetics. These systems combined with demand management
from tools such as low-flow toilets can reduce urban indoor use in the USA from over
400 liters per capital per day (l/c/d) to 120 l/c/d to 150 l/c/d. He states these advanced
systems will be economic when comparing all the costs and benefits. Zoltay et al (2010)
illustrated these concepts in a case study in the Northeastern USA. Use of reclaimed
or recycled water also removes some of the variability in water supply sources. Such a
system must monitor possible public health problems and build up of pollutants in the
closed loop systems.
River Flooding
Galloway (2009) reports upon guidelines developed by the Association of State Flood-
plain Managers (ASFPM) and recommends these be used to guide floodplain manage-
ment over the next decades to respond to climate change as well as other river flood
stressors. These include ”Make room for rivers, oceans, and adjacent lands; Reverse
perverse incentives in government programs that make it more profitable to act un-
wisely than to recognize the need for long term safety and sustainability; Restore and
enhance the natural, beneficial functions of riverine and coastal areas; Generate a renais-
sance in water resources governance and development of the policies and organization
that will support this renaissance; Identify risks and resources and communicate at pub-
lic and individual levels; Assume personal and public responsibility for their actions
in the floodplain.”(page 2333) . He also supports the recent switch to risk-based flood
management by the US Army Corps of Engineers. Opperman et al. (2009) support simi-
lar concepts. Flood management will also be improved by beter weather and seasonal
climate forecasting of precipitation and associated runoff.
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