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048 | WATER
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water |
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Water is a crucial natural resource, not only for domestic,
but also for industrial and agricultural use. Various natural factors, such
as soil fertility, depend on the availability of water of acceptable quality
and sufficient quantity. Surface waters are rich natural habitats, feeding
and breeding grounds. Pressure on the availability of clean water generally
derives from human use and pollution. For example, the Rhine is heavily
polluted: the nutrient load amounted in 1982 to 23,000 tonnes of orthophosphate
per year, 350,000 tonnes of nitrate per year and 5,600,000 tonnes of sulphate
per year. The total quantity of chlorides present in the river is in excess
of 11 million tonnes annually.
In the Sustainable Europe study fresh water is the only resource considered
to have a predominantly local or regional character. The environmental space
for water is determined by sustainable extraction of water from the environment.
Since the availability of ground and surface water differs significantly
from place to place, every region of a country must adapt its use of water
to its specific environmental space. Reduction requirements cannot be calculated
meaningfully at a European average scale, but in many local and regional
situations a reduction of water use may be necessary. The case of the Rhein-Main
area, presented below, gives an idea of the diverse problems that need to
be taken into account in developing sustainable water management practices. |
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case study: the rhein-main
area |
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| Although Germany has large water resources at its disposal,
water supply for its large urban agglomerations has become increasingly
problematic. More than 70 per cent of their drinking water is provided by
ground-water which has to be transported over long distances from the rural
surroundings into the urban areas. The extraction of water has caused significant
drops in ground-water levels and has had destructive impacts on river ecosystems
and forests. Since current water management aims at meeting the steadily
increasing demand for high-quality water, even deep ground-water resources
(so-called 'pleistocene' water) are exploited. From an environmental point
of view this is unacceptable. Sustainable water management has to be based
on the average rainfall of the region, extracting water resources only to
the extent of their renewability. A strategy for sustainable water use may
consist of the following components (Figures refer to the Rhein-Main area): |
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Direct savings of drinking-quality water use: There is a reduction
potential of nearly 50 per cent in the use of drinking-quality water in
the public sector (schools, swimming pools, other public facilities), and
a reduction potential of 40 per cent is estimated for industry. In private
households and small enterprises only a reduction of 10 per cent seems to
be feasible. Reduction of losses in distribution can also be significant. |
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Indirect savings through the substitution of drinking water
by non-potable water: The use of non-potable water is still uncommon, but
for many purposes there is no need for drinking quality water (e.g. toilets,
car-washing etc.). Currently there are several technologies for substitution
available, including |
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the collection of surface water for direct use, for example for irrigation
of public facilities such as parks; |
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recycling of water within buildings; and |
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the installation of separated water pipes for drinking water and non-potable
water. Because of high costs and the great amount of material needed for
the construction, a separated non-potable water pipe network is only feasible
in areas of high density of consumers, such as dense urban areas. These
pipes can be fed direct from collected rainfall, or by any kind of surface
water. In Germany there were dual supply systems networks in several districts
of a number of cities up to about 1960 (e.g. Hannover, Frankfurt, Wiesbaden). |
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sector specific measures
and strategies |
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Energy | more
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Water | more
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more |
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Water
Briefing by Friends of the Earth England, Wales and Northern Ireland |
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