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SECTION
3 NATURAL RESOURCES CAPITAL STOCK
| 3.4 |
Freshwater
Resources |
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| 3.4.1
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Existing
Capital Stock and Trends |
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Demand
for Freshwater
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| 3.4.1.1
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The
total demand for freshwater resources is
a function of the volume required for domestic,
commercial, industrial and other purposes
(which depends on population as well as
the types and level of industrial activity),
the efficiency with which freshwater is
supplied, and the alternatives available
as substitutes. For the two decades preceding
1990, demand for freshwater grew at an average
rate of 6% per annum primarily due to population
growth, the extension of supply to remote
areas such as new towns, improved standards
of living and a rapidly expanding economy.
Since 1990, however, the rate of growth
of the overall water demand has fluctuated
within a decreasing trend such that the
average annual growth rate in freshwater
demand for the nine years up to and including
1998 was 0.9% (WSD 1999).
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| 3.4.1.2 |
Although
the rate of growth in demand has slowed,
it is still positive and thus the amount
of freshwater required each year in absolute
terms continues to increase. However, when
demand is examined with reference to population,
per capita demand is shown to be declining
with time. The Water Supplies Department
routinely calculates per capita water consumption
statistics, referred to as Gross Per Capita
Consumption (GPCC) which is defined as the
output from freshwater treatment works (ie
supplied) divided by the population. Quantities
for the period 1990 to 1998 are shown in
Table 3.4a below. When interpreting the
GPCC statistics it is important to note
that these data reflect the significant
decrease in industrial water consumption
as a result of the relocation of industries
outside of Hong Kong and thus do not necessarily
indicate that domestic per capita usage
is declining.
| Table
3.4a Annual Water Consumption for Hong
Kong (1990-1998) |
| Year |
Population |
Total
Volume of Freshwater Supplied
(m-3 year-1)
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Volume
of Freshwater Supplied per Capita
(m-3 year-1)
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| 1990 |
5,704,500 |
873,000,000 |
153.0 |
| 1991 |
5,752,000 |
884,000,000 |
153.7 |
| 1992 |
5,800,500 |
889,000,000 |
153.3 |
| 1993 |
5,901,000 |
915,000,000 |
155.1 |
| 1994 |
6,035,400 |
923,000,000 |
152.9 |
| 1995 |
6,156,100 |
919,000,000 |
149.3 |
| 1996 |
6,311,000 |
928,000,000 |
147.0 |
| 1997 |
6,502,100 |
913,000,000 |
140.4 |
| 1998 |
6,687,200 |
916,000,000 |
137.0 |
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| 3.4.1.3 |
The
level of provision of potable water to domestic
properties in Hong Kong is high, with 99.8%
of the population served. When assessing the
volume of freshwater demand it is important
to consider the efficiency with which freshwater
is delivered to end users. While potable water
treatment processes may result in some loss
in volume, the primary factor is the rate
of leakage within the supply system. In Hong
Kong the estimated rate of loss from supply
pipes and infrastructure is 22.5% (WSD 1998). |
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| 3.4.1.4 |
Another
feature in the slowing rate of growth of demand
for freshwater may also be the increase in
seawater used for lavatory flushing water.
The use of seawater for flushing water reduces
the demand on existing freshwater resources
and thus enhances the efficiency of use of
the natural freshwater resource. In Hong Kong
seawater is abstracted from a total of 17
intake points and undergoes basic treatment
(screening and chlorination) prior to use.
Over the period from 1990 to 1998, the percentage
of flushing water derived from seawater abstraction
grew from 59.2% to 72.8%. At present over
three quarters of the population is supplied
with flushing water and the supply system
is being expanded with plant recently completed
at Tseung Kwan O, Sha Tin, Ma On Shan and
Tai Po (WSD 1998). |
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