Geography Reference
In-Depth Information
Figure 10.1 shows the stylised structure of the water
supply system and incorporates the three
requirements above. Water supply cannot be
separated from water quality issues. There are
inherent and demanding standards of quality for
potable waters. After use, potable waters are
discharged into the sewer system and after
treatment to the natural environment. At each stage
from resource development to return of effluent to
the natural environment the supply system is
formally monitored by several agencies, which are
also shown in Figure 10.1. In this section,
environmental water quality is not considered but
it is treated elsewhere; see Chapter 11.
The structure of the water industry in the
United Kingdom has evolved over the years.
Broadly, that evolution can be considered as falling
into four phases, namely:
their own water undertakings, each city being
supplied by its own reservoir system
independently from the resource developments of
adjacent cities. Reservoir developments required
an act of parliament and involved the construction
of both supply reservoirs and reservoirs to
compensate downstream mill owners for the
changed water conditions to which they, as
riparian owners, were being subjected. For over
100 years, the situation remained unchanged,
although the scale of the reservoirs increased and
the size of catchwaters and aqueducts increased
dramatically. In essence, however, the country had
water provided by a set of independent unlinked
source-sink resource exploitation systems. Each
supply relied on four lines of defence, the so-called
multiple barrier concept:
•
a pristine catchment;
•
pre-1850
•
long storage in a large reservoir;
•
1850-1974
•
filtration; and
•
1974-89
•
disinfection.
•
post-1989.
Certainly, the first two lines of defence have
eroded over the years with the pressure of demand
(1) for land, (2) for access, (3) for increased water
sport and (4) for preferential exploitation of cheap
upland waters. The final line of defence, while not
eroded, has come under growing criticism because
of problematic side effects. The use of chlorination
is criticised because it generates trihalomethanes
when applied to the organic-rich peat-derived
waters from British uplands. Chlorination is
widely accepted in the UK but is not popular in
Europe. The generation of organic-rich water is
discussed in Mitchell (1990) and management
implications in Mitchell and McDonald (1995).
Pre c.1850
Before 1850, the water supply in the UK was
small-scale, with local communities being supplied
from the local river or well. Such a situation had
existed for 1500 years, and any lessons that might
have been learned from the relatively sophisticated
Roman water supply systems had been lost to the
indigenous community. The small, dispersed
population had, for the most part, relied on the
natural purification capacities of the natural
environment. As industrialisation and urbanisation
increased, cities' local water supplies became more
and more inadequate and waterborne disease
reached, literally, epidemic proportions
(McDonald and Kay 1988).
1974-89
Concern about the fragmented and piecemeal
structure of the British water industry, which had
hundreds of suppliers and thousands of waste
management agencies, led to the creation of the
regional water authorities in England and Wales.
Ten water authorities covered the country, nine in
England and a further Welsh Water Authority. A
form of the previous system remained in Scotland
1850-1974
The real driver to change then, was disease in the
cities, the government response to which was
focused through a Victorian sense of civic pride
and independence. City corporations developed
