1.2.13 Water
Water is a natural resource which is essential for the survival of man and for his
activities, especially his economic activities because it cannot be replaced in most of
its uses. It is not only an essential element for life but also, in the twofold aspect of
quality and quantity, a conditioning factor of economic growth and of social welfare.
Water supplies in small quantities for domestic use can be obtained from rivers by
direct abstraction, without any storage impoundment, but this, of course, limits the
water flow available to only a fraction of the dry weather river flow. In that case,
impounding of rivers can become more frequent. In some cases, tapping underground sources may be necessary.
Characteristics of Good Quality Water: These can be listed as follows:
1. It must be pleasant to taste and appearance.
2. It must be free from pathogenic organisms.
3. It must be free from toxic substance.
4. It should not be corrosive in nature.
5. It should not contain excessive amount of solid substances which cause physiological effects on human beings and other consumers.
6. It should have sufficient quantity of dissolved oxygen.
7. It should be available in large quantities.
Should impoundment be implemented for some other purpose, such as hydrogeneration, it might be possible to use the tail race water for domestic water supply or
eventually, direct from the reservoir. Water needs for domestic purposes are usually
quite small when compared to water requirements for irrigation and for generation of
electricity.
Per capita water consumption depends on numerous social and economic factors,
more particularly, the way the water is supplied. The daily basic consumption, for
example, when water is supplied from public fountains, varies between 5 and
20 Litres/person, but for houses equipped with flush toilets, baths, sinks, lavatories
and wash tubs the daily quantities of water used reach 120 Litres/person, and in
certain places may reach average daily values of about 250 to 1000 Litres/person, for
all domestic uses, irrespective of water being metered or not.
The requirements for industry differ from domestic water use in two ways:
(1) Quality: water used for industrial need not always satisfy the same standards of
purity. Thus, sometimes, the effluent from the municipal sewage purification
works, though unsuitable for domestic consumption, may be used for washing,
cleaning, cooling, etc. Sometimes, however, even water suitable for domestic
use needs its iron contents to be removed before it can be used for dyeing
textiles; otherwise, the textiles get reddish stains.
(2) Future water requirements: For a given population, it is not difficult to forecast
possible population growth, from which water requirements for domestic use in
the future may be determined. This enables project planning schemes which can
provide these future needs, for domestic purposes. However, industries depend
26
1 Introduction to Infrastructure
Water is a natural resource which is essential for the survival of man and for his
activities, especially his economic activities because it cannot be replaced in most of
its uses. It is not only an essential element for life but also, in the twofold aspect of
quality and quantity, a conditioning factor of economic growth and of social welfare.
Water supplies in small quantities for domestic use can be obtained from rivers by
direct abstraction, without any storage impoundment, but this, of course, limits the
water flow available to only a fraction of the dry weather river flow. In that case,
impounding of rivers can become more frequent. In some cases, tapping underground sources may be necessary.
Characteristics of Good Quality Water: These can be listed as follows:
1. It must be pleasant to taste and appearance.
2. It must be free from pathogenic organisms.
3. It must be free from toxic substance.
4. It should not be corrosive in nature.
5. It should not contain excessive amount of solid substances which cause physiological effects on human beings and other consumers.
6. It should have sufficient quantity of dissolved oxygen.
7. It should be available in large quantities.
Should impoundment be implemented for some other purpose, such as hydrogeneration, it might be possible to use the tail race water for domestic water supply or
eventually, direct from the reservoir. Water needs for domestic purposes are usually
quite small when compared to water requirements for irrigation and for generation of
electricity.
Per capita water consumption depends on numerous social and economic factors,
more particularly, the way the water is supplied. The daily basic consumption, for
example, when water is supplied from public fountains, varies between 5 and
20 Litres/person, but for houses equipped with flush toilets, baths, sinks, lavatories
and wash tubs the daily quantities of water used reach 120 Litres/person, and in
certain places may reach average daily values of about 250 to 1000 Litres/person, for
all domestic uses, irrespective of water being metered or not.
The requirements for industry differ from domestic water use in two ways:
(1) Quality: water used for industrial need not always satisfy the same standards of
purity. Thus, sometimes, the effluent from the municipal sewage purification
works, though unsuitable for domestic consumption, may be used for washing,
cleaning, cooling, etc. Sometimes, however, even water suitable for domestic
use needs its iron contents to be removed before it can be used for dyeing
textiles; otherwise, the textiles get reddish stains.
(2) Future water requirements: For a given population, it is not difficult to forecast
possible population growth, from which water requirements for domestic use in
the future may be determined. This enables project planning schemes which can
provide these future needs, for domestic purposes. However, industries depend
26
1 Introduction to Infrastructure