BEAM Plus New Buildings

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BEAM PLUS FOR NEW BUILDINGS WATER USE (WU)
V ERSION 1.2
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Page 122
cubic metres while the average daily use of sea water for flushing stood
at 0.74 million cubic metres [3]. Total freshwater consumption was 951
million cubic metres, with domestic consumption accounting for over
50%, and around 25% consumed by the service trade. Despite the
continued decline in industrial consumption there is an annual trend of
rising consumption due to increasing domestic consumption. Based on
projected population growth for the period, the domestic and service
uses, being the key components of our fresh water consumption, are
expected to increase. Industrial use, for the same period, is expected to
drop because of further decline in water intensive industries. Wider use
of fresh water in water-cooled air-conditioning systems (WACS) will
contribute to consumption by the non-domestic sector.
CONSERVATION Although the demand growth has slowed in recent years, additional
water resources are still required to secure a full supply. The lack of
reservoir sites and high development costs limit the development of
further areas as water-gathering grounds. Other than expanding the use
of sea water for flushing and adopting water conservation measures,
Hong Kong has few options to reduce dependency on the Mainland.
There is opportunity to reduce potable water use through better design,
management and user awareness. There are also opportunities to
recycle used water and rain water in order to reduce the use of potable
water. Additional benefits of potable water conservation are reduced
energy use for transport and the cost of treatment of raw water.
BENCHMARKS Given the paucity of available data for Hong Kong and variability of
circumstances for different buildings and uses, BEAM provides default
assumptions for the calculation of the reduction in water consumption of
the project building when compared with an equivalent baseline case.
The default assumption including the flow rate and operating time of the
water device are given in Appendix 8.6. An information paper is also
available that explain the basis and origins of the default assumption.
Consequently, it is feasible to provide an exact target for reducing
consumption with the baseline.
5.2 EFFLUENT WU 6 EFFLUENT DISCHARGE TO FOUL SEWERS
BACKGROUND Whilst some 80% of users in Hong Kong are supplied with seawater for
flushing purposes there are environmental impacts associated with the
treatment and delivery of seawater, and the load imposed on municipal
sewage treatment plants. Measures taken to reduce volumes of effluent
flows have significant environmental benefits.
3 Water Supplies Department. Annual Report.