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WATER MANAGEMENT[Type the document subtitle]
11\01\2010
[Type the company name]
FAIZAN MANSURI
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WATER MANAGEMENT
I. IntroductionII. What is water?
III. What are sources of water?1) surface water
Surface water is water in a river, lake or fresh water wetland. Surface water is naturally replenished by
precipitation and naturally lost through discharge to the oceans, evaporation, and sub-surface seepage.
Although the only natural input to any surface water system is precipitation within its watershed, the
total quantity of water in that system at any given time is also dependent on many other factors. These
factors include storage capacity in lakes, wetlands and artificial reservoirs, the permeability of the soil
beneath these storage bodies, the runoff characteristics of the land in the watershed, the timing of the
precipitation and local evaporation rates. All of these factors also affect the proportions of water lost.
Human activities can have a large and sometimes devastating impact on these factors. Humans often
increase storage capacity by constructing reservoirs and decrease it by draining wetlands. Humans often
increase runoff quantities and velocities by paving areas and channelizing stream flow.
The total quantity of water available at any given time is an important consideration. Some human
water users have an intermittent need for water. For example, many farms require large quantities of
water in the spring, and no water at all in the winter. To supply such a farm with water, a surface water
system may require a large storage capacity to collect water throughout the year and release it in ashort period of time. Other users have a continuous need for water, such as a power plant that requires
water for cooling. To supply such a power plant with water, a surface water system only needs enough
storage capacity to fill in when average stream flow is below the power plant's need.
Nevertheless, over the long term the average rate of precipitation within a watershed is the upper
bound for average consumption of natural surface water from that watershed.
Natural surface water can be augmented by importing surface water from another watershed through a
canal or pipeline. It can also be artificially augmented from any of the other sources listed here, however
in practice the quantities are negligible. Humans can also cause surface water to be "lost" (i.e. become
unusable) through pollution.
Brazil is the country estimated to have the largest supply of fresh water in the world, followed by Russia
and Canada.
2) Under river flow
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Throughout the course of the river, the total volume of water transported downstream will often be a
combination of the visible free water flow together with a substantial contribution flowing through sub-
surface rocks and gravels that underlie the river and its floodplain called the hyporheic zone. For many
rivers in large valleys, this unseen component of flow may greatly exceed the visible flow. The hyporheic
zone often forms a dynamic interface between surface water and true ground-water receiving water
from the ground water when aquifers are fully charged and contributing water to ground-water when
ground waters are depleted. This is especially significant in karst areas where pot-holes and
underground rivers are common.
3) GroundwaterSub-surface water, or groundwater, is fresh water located in the pore space of soil and rocks. It is also
water that is flowing within aquifers below the water table. Sometimes it is useful to make a distinction
between sub-surface water that is closely associated with surface water and deep sub-surface water in
an aquifer (sometimes called "fossil water").
Sub-surface water can be thought of in the same terms as surface water: inputs, outputs and storage.
The critical difference is that due to its slow rate of turnover, sub-surface water storage is generally
much larger compared to inputs than it is for surface water. This difference makes it easy for humans to
use sub-surface water unsustainably for a long time without severe consequences. Nevertheless, over
the long term the average rate of seepage above a sub-surface water source is the upper bound for
average consumption of water from that source.
The natural input to sub-surface water is seepage from surface water. The natural outputs from sub-
surface water are springs and seepage to the oceans.
If the surface water source is also subject to substantial evaporation, a sub-surface water source maybecome saline. This situation can occur naturally under endorheic bodies of water, or artificially under
irrigated farmland. In coastal areas, human use of a sub-surface water source may cause the direction of
seepage to ocean to reverse which can also cause soil salinization. Humans can also cause sub-surface
water to be "lost" (i.e. become unusable) through pollution. Humans can increase the input to a sub-
surface water source by building reservoirs or detention ponds.
4) DesalinationD
esalination is an artificial process by which saline water (generally sea water) is converted to freshwater. The most common desalination processes are distillation and reverse osmosis.Desalination is
currently expensive compared to most alternative sources of water, and only a very small fraction of
total human use is satisfied by desalination. It is only economically practical for high-valued uses (such as
household and industrial uses) in arid areas. The most extensive use is in the Persian Gulf.
5) Frozen water
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Several schemes have been proposed to make use of icebergs as a water source, however to date this
has only been done for novelty purposes. Glacier runoff is considered to be surface water.
The Himalayas, which are often called "The Roof of the World", contain some of the most extensive and
rough high altitude areas on Earth as well as the greatest area of glaciers and permafrost outside of the
poles. Ten of Asias largest rivers flow from here, and more than a billion peoples livelihoods depend onthem. To complicate matters, temperatures are rising more rapidly here than the global average. In
Nepal the temperature has risen with 0.6 degree over the last decade, whereas the global warming has
been around 0.7 over the last hundred years.
IV. What are the uses of water?1) Agricultural
It is estimated that 69% of worldwide water use is for irrigation, with 15-35% of irrigation withdrawals
being unsustainable.
In some areas of the world irrigation is necessary to grow any crop at all, in other areas it permits more
profitable crops to be grown or enhances crop yield. Various irrigation methods involve different trade-
offs between crop yield, water consumption and capital cost of equipment and structures. Irrigation
methods such as furrow and overhead sprinkler irrigation are usually less expensive but are also
typically less efficient, because much of the water evaporates, runs off or drains below the root zone.
Other irrigation methods considered to be more efficient include drip or trickle irrigation, surge
irrigation, and some types of sprinkler systems where the sprinklers are operated near ground level.
These types of systems, while more expensive, usually offer greater potential to minimize runoff,
drainage and evaporation. Any system that is improperly managed can be wasteful, all methods have
the potential for high efficiencies under suitable conditions, appropriate irrigation timing and
management. One issue that is often insufficiently considered is salinization of sub-surface water.
Aquaculture is a small but growing agricultural use of water. Freshwater commercial fisheries may also
be considered as agricultural uses of water, but have generally been assigned a lower priority than
irrigation (see Aral Sea and Pyramid Lake).
As global populations grow, and as demand for food increases in a world with a fixed water supply,
there are efforts underway to learn how to produce more food with less water, through improvements
in irrigation methods and technologies, agricultural water management, crop types, and water
monitoring.
2) Industrial
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It is estimated that 15% of worldwide water use is industrial. Major industrial users include power
plants, which use water for cooling or as a power source (i.e. hydroelectric plants), ore and oil refineries,
which use water in chemical processes, and manufacturing plants, which use water as a solvent.
The portion of industrial water usage that is consumptive varies widely, but as a whole is lower than
agricultural use.
Water is used in power generation. Hydroelectricity is electricity obtained from hydropower.
Hydroelectric power comes from water driving a water turbine connected to a generator.
Hydroelectricity is a low-cost, non-polluting, renewable energy source. The energy is supplied by the
sun. Heat from the sun evaporates water, which condenses as rain in higher altitudes, from where it
flows down.
Three GorgesDam is the largest hydro-electric power station Pressurized water is used in water blasting
and water jet cutters. Also, very high pressure water guns are used for precise cutting. It works very
well, is relatively safe, and is not harmful to the environment. It is also used in the cooling of machinery
to prevent over-heating, or prevent saw blades from over-heating.
Water is also used in many industrial processes and machines, such as the steam turbine and heat
exchanger, in addition to its use as a chemical solvent. Discharge of untreated water from industrial uses
is pollution. Pollution includes discharged solutes (chemical pollution) and discharged coolant water
(thermal pollution). Industry requires pure water for many applications and utilizes a variety of
purification techniques both in water supply and discharge.
3) HouseholdIt is estimated that 15% of worldwide water use is for household purposes. These include drinking
water, bathing, cooking, sanitation, and gardening. Basic household water requirements have been
estimated by Peter Gleick at around 50 liters per person per day, excluding water for gardens. Drinking
water is water that is of sufficiently high quality so that it can be consumed or used without risk of
immediate or long term harm. Such water is commonly called potable water. In most developed
countries, the water supplied to households, commerce and industry is all of drinking water standard
even though only a very small proportion is actually consumed or used in food preparation.
4) RecreationalRecreational water use is usually a very small but growing percentage of total water use. Recreational
water use is mostly tied to reservoirs. If a reservoir is kept fuller than it would otherwise be for
recreation, then the water retained could be categorized as recreational usage. Release of water from a
few reservoirs is also timed to enhance whitewater boating, which also could be considered a
recreational usage. Other examples are anglers, water skiers, nature enthusiasts and swimmers.
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Recreational usage is usually non-consumptive. Golf courses are often targeted as using excessive
amounts of water, especially in drier regions. It is, however, unclear whether recreational irrigation
(which would include private gardens) has a noticeable effect on water resources. This is largely due to
the unavailability of reliable data. Some governments, including the Californian Government, have
labelled golf course usage as agricultural in order to deflect environmentalists' charges of wasting water.
However, using the above figures as a basis, the actual statistical effect of this reassignment is close to
zero.
Additionally, recreational usage may reduce the availability of water for other users at specific times and
places. For example, water retained in a reservoir to allow boating in the late summer is not available to
farmers during the spring planting season. Water released for whitewater rafting may not be available
for hydroelectric generation during the time of peak electrical demand.
5) EnvironmentalExplicit environmental water use is also a very small but growing percentage of total water use.
Environmental water usage includes artificial wetlands, artificial lakes intended to create wildlife
habitat, fish ladders around dams, and water releases from reservoirs timed to help fish spawn.
Like recreational usage, environmental usage is non-consumptive but may reduce the availability of
water for other users at specific times and places. For example, water release from a reservoir to help
fish spawn may not be available to farms upstream.
V. What is water management?VI. What is water cycle?
The Water Cycle (also known as the hydrologic cycle) is the journey water takes as it circulates from the
land to the sky and back again.
The Sun's heat provides energy to evaporate water from the Earth's surface (oceans, lakes, etc.). Plants
also lose water to the air (this is called transpiration). The water vapor eventually condenses, forming
tiny droplets in clouds. When the clouds meet cool air over land, precipitation (rain, sleet, or snow) is
triggered, and water returns to the land (or sea). Some of the precipitation soaks into the ground. Some
of the underground water is trapped between rock or clay layers; this is called groundwater. But most ofthe water flows downhill as runoff (above ground or underground), eventually returning to the seas as
slightly salty water.
VII. Why is ocean water salty?
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As water flows through rivers, it picks up small amounts of mineral salts from the rocks and soil of the
river beds. This very-slightly salty water flows into the oceans and seas. The water in the oceans only
leaves by evaporating (and the freezing of polar ice), but the salt remains dissolved in the ocean - it does
not evaporate. So the remaining water gets saltier and saltier as time passes.
VIII. Daily requirements of water for one person.IX. How water management is essential?X. Water Conservation
XI. What is water crisis?Mumbai water crisis
Mumbai disrupted by water shortages (BBC) MUMBAI, India In a suburban Mumbai home, simple
tasks like doing the dishes are made difficult for busy mother-of-two Neeta Mehta.
Water is supplied to Ms Mehtas home only once a day for a few hours in the morning, which means she
has to try and store water while the taps are running.
We regularly need water for the whole day and when it only runs for a few hours, it is very difficult to
keep the whole house clean.
Millions of Mumbai residents are in the same boat. The city needs four billion litres of drinking water
every day to service the needs of all its residents.
However, the main civic body responsible for the citys water supply, the Brihanmumbai Municipal
Corporation (BMC), reports that it can only supply 3.3 billion litres a day.
Anil Diggiker, the BMCs additional commissioner, says they are trying to address the shortage.
We will have to augment alternate water sources like rain water harvesting, dug wells and bore wells,
he explains. People should not waste the water.
This years less-than-average monsoon rains that have amplified the water shortages and highlighted
the citys ageing infrastructure system that is in need of heavy investment.
Unless a longer-term solution and a collective effort to conserve water is put in place, then many
analysts worry that Mumbais 20 million or so residents could be left high and dry.
XII. What is rain water harvesting?Rainwater harvesting is the gathering, or accumulating and storing, of rainwater.[1] Rainwater
harvesting has been used to provide drinking water, water for livestock, water for irrigation or to refill
aquifers in a process called groundwater recharge. Rainwater collected from the roofs of houses, tents
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and local institutions, or from specially prepared areas of ground, can make an important contribution
to drinking water. In some cases, rainwater may be the only available, or economical, water source.
Rainwater systems are simple to construct from inexpensive local materials, and are potentially
successful in most habitable locations. Roof rainwater is usually of good quality and does not require
treatment before consumption. Household rainfall catchment systems are appropriate in areas with an
average rainfall greater than 200mm per year, and no other accessible water sources (Skinner and
Cotton, 1992).
There are a number of types of systems to harvest rainwater ranging from very simple to the complex
industrial systems. Generally, rainwater is either harvested from the ground or from a roof. The rate at
which water can be collected from either system is dependent on the plan area of the system, its
efficiency, and the intensity of rainfall.
Advantages in urban areas
Rainwater harvesting in urban areas can have manifold reasons. Some of the reasons rainwater
harvesting can be adopted in cities are to provide supplemental water for the city's requirements, to
increase soil moisture levels for urban greenery, to increase the ground water table through artificial
recharge, to mitigate urban flooding and to improve the quality of groundwater. In urban areas of the
developed world, at a household level, harvested rainwater can be used for flushing toilets and washing
laundry. Indeed in hard water areas it is superior to mains water for this. It can also be used for
showering or bathing. It may require treatment prior to use for drinking
In New Zealand, many houses away from the larger towns and cities routinely rely on rainwater
collected from roofs as the only source of water for all household activities. This is almost inevitably the
case for many holiday homes.
Quality
As rainwater may be contaminated, it is often not considered suitable for drinking without treatment.
However, there are many examples of rainwater being used for all purposes including drinking
following suitable treatment.
Rainwater harvested from roofs can contain animal and bird faeces, mosses and lichens, windblown
dust, particulates from urban pollution, pesticides, and inorganic ions from the sea (Ca, Mg, Na, K, Cl,
SO4), and dissolved gases (CO2, NOx, SOx). High levels of pesticide have been found in rainwater in
Europe with the highest concentrations occurring in the first rain immediately after a dry spell; the
concentration of these and other contaminants are reduced significantly by diverting the initial flow ofwater to waste as described above. The water may need to be analysed properly, and used in a way
appropriate to its safety. In the Gansu province for example, harvested rainwater is boiled in parabolic
solar cookers before being used for drinking. In Brazil alum and chlorine is added to disinfect water
before consumption. So-called "appropriate technology" methods, such as solar water disinfection,
provide low-cost disinfection options for treatment of stored rainwater for drinking.
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System sizing
It is important that the system is sized to meet the water demand throughout the dry season. Generally
speaking, the size of the storage tank should be big enough to meet the daily water requirement
throughout the dry season. In addition, the size of the catchment area or roof should be large enough to
fill the tank.
Around the world
Currently in China and Brazil, rooftop rainwater harvesting is being practiced for providing drinking
water, domestic water, water for livestock, water for small irrigation and a way to replenish ground
water levels. Gansu province in China and semi-arid north east Brazil have the largest rooftop rainwater
harvesting projects ongoing.
In Rajasthan, India rainwater harvesting has traditionally been practiced by the people of the Thar
Desert.
In Bermuda, the law requires all new construction to include rainwater harvesting adequate for the
residents.
The U.S. Virgin Islands have a similar law.
In the Indus Valley Civilization, Elephanta Caves and Kanheri Caves in Mumbai rainwater harvesting
alone has been used to supply in their water requirements.
In Senegal/Guinea-Bissau, the houses of theDiola-people are frequently equipped with homebrew
rainwater harvesters made from local, organic material.
In the United Kingdom water butts are oft-found in domestic gardens to collect rainwater which is then
used to water the garden.
In the Ayerwaddy Delta of Myanmar, the groundwater is saline and communities rely on mud lined
rainwater ponds to meet their drinking water needs throughout the dry season. Some of these ponds
are centuries old and are treated with great reverence and respect.
Until 2009 in Colorado, water rights laws restricted rainwater harvesting; a property owner who
captured rainwater was deemed to be stealing it from those who have rights to take water from the
watershed. The main factor in persuading the Colorado Legislature to change the law was a 2007 study
that found that in an average year, 97% of the precipitation that fell in Douglas County, in the southern
suburbs ofDenver, never reached a streamit was used by plants or evaporated on the ground. In Utah
and Washington State, collecting rainwater from the roof is illegal unless the roof owner also owns
water rights on the ground. In New Mexico, rainwater catchment is mandatory for new dwellings in
Santa Fe.
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XIII. What is water pollution? & control steps to control it.XIV. Conclusion
Whether too much or not enough, the world needs a smarter way to think about water