Rethinking Infrastructure Design - Rethinking Infrastructure Design for Multi-Use Water Services - page 5

3 What Is Wrong with Existing Systems?

When the problems of climate change became obvious (through extremes), many
people thought about our relationship with the environment. Even in the 1970s,
questions of population, food production, industrial production, pollution and
consumption of non-renewable natural resources rose as problems of non-long-term
viability of modern cities were introduced.
Traditional engineering design of structures and systems exposed to impacts of
stochastic conditions (variables) was to adapt the acceptable risk (thus costs) to
selected return periods. However, the climate changes created issues with this
methodology since the systems designed to sustain certain return period are now
exposed to the same extreme conditions more frequently. Recently, Fratini et al.
( 2012 )

this method by introducing so-called Three Points Approach
(3PA) to be used in analysis of adaptations to climate changes. If one single
function (

' customised '

(flood for example) of a technical system were analysed in isolation, in
order to adapt for climate changes, one would have to invest heavily into increasing
its capacity ( ).

Traditional water management, which treats elements of the urban water system
as isolated services, has led to an unbalanced urban

' rich men ' s solution '

' metabolism ' (Novotny et al.

2010 ). It is an inef cient, unsecure and separated centralised system. On one side of

the system there is (energy and chemically

intensive), whose capacities are being exceeded by rapid urbanisation. In extreme
cases (California for example), even if almost all water resources from the broader
region are captured and used, the system has reached the maximum natural capacity
to support it. At the other end of the system is the wastewater treatment plant. Plants
that are environmentally unfriendly (impact of sludge and chemically intensive) and
use lots of space (from nature and agriculture) are having problems accepting and
treating a combined quantity of storm and wastewater. Furthermore, the extent of
paved areas inside urban areas, during extreme rain events, generate large amount
of polluted run-off that wastewater treatment plants cannot obtain. Thus, untreated
water (blend of raw sewerage and storm run-off) is released to surface waters
(rivers, ponds, lakes, etc.), which leads to environmental degradation. This process
is illustrated in Fig. 4 , which depicts the conventional urban drainage systems with
and without wastewater treatment plants.
To sum up, the quantity of water in cities is a problem today

' production of drinking water supply '

both shortage and
excess. A new approach is clearly needed. An approach that can resolve water
problems, provide multiple environmental bene

—

ts and support sustainable devel-
opment (US Environmental Protection Agency (US-EPA) ( 2012 )). One solution
uses natural processes and location characteristics in order to reduce negative
footprints cities have on the environment. Integrated urban water management is no
one-size-

s
relationships to water and other resources, and conceptualises the ways in which
they can be overseen. The goals of urban water management are to ensure access to
water and sanitation infrastructure and services (in the least developed countries this

ts-all model nor is one model suf cient. Rather, it reframes a city '