Water is one of the renewable resources essential for sustaining all forms of life, food production, economic development, and for general well being. It is impossible to substitute for most of its uses, difficult to depollute, expensive to transport, and it is truly a unique gift to mankind from nature. Water is also one of the most manageable natural resources as it is capable of diversion, transport, storage, and recycling. All these properties impart to water its great utility for human beings. The surface water and groundwater resources of the country play a major role in agriculture, hydropower generation, livestock production, industrial activities, forestry, fisheries, navigation, recreational activities etc. The freshwater ecosystems of the world comprise only about 0.5% of the earth’s surface

India is gifted with river system comprising more than 20 major rivers with several tributaries. Many of these rivers are perennial and some of them are seasonal.

The importance of water

Water is one of the most important substances on earth. All plants and animals must have water to survive. If there was no water there would be no life on earth.

Apart from drinking it to survive, people have many other uses for water. These include:

1. cooking
2. washing their bodies
3. washing clothes
4. washing cooking and eating utensils; such as billies, saucepans, crockery and cutlery
5. keeping houses and communities clean
6. recreation; such as swimming pools
7. keeping plants alive in gardens and parks

Water is also essential for the healthy growth of farm crops and farm stock and is used in the manufacture of many products.

It is most important that the water which people drink and use for other purposes is clean water. This means that the water must be free of germs and chemicals and be clear (not cloudy).

Water that is safe for drinking is called potable water.

Disease-causing germs and chemicals can find their way into water supplies. When this happens the water becomes polluted or contaminated and when people drink it or come in contact with it in other ways they can become very sick.

Water that is not safe to drink is said to be non-potable. Throughout history there have been many occasions when hundreds of thousands of people have died because disease-causing germs have been spread through a community by a polluted water supply.

One of the reasons this happens less frequently now is that people in many countries make sure drinking water supplies are potable. Water supplies are routinely checked for germs and chemicals which can pollute water. If the water is not safe to drink it is treated. All the action taken to make sure that drinking water is potable is called water treatment.

• Water is a highly valuable, limited resource.
• Water costs a great deal in energy and money to pump, move and purify.
• Water consumption can be reduced significantly in the average home.

Generating Electricity:-

Water flowing from a dam or waterfall spins a shaft coupled to a generator. The generator is basically a large coil of wires, like a donut, surrounding a magnet in the donut hole. The magnet is connected to the shaft that the water spins, so that the magnet spins inside the wire coils. This creates electricity.

Hydroelectric energy can be defined as a form of hydropower where the motion of running water (kinetic energy) is converted into electricity. The water cycle is driven directly by solar energy. When the sun heats the water in the ocean, some of the water on the surface is vaporized.

(work) https://www.youtube.com/watch?v=pEUzot8Zufo

https://www.youtube.com/watch?v=ABv631t1OKI

Sources of water

Surface water: This is water which falls to the ground as rain or hail. 

This water is collected from a special area called a catchment. The catchment feeds water into a holding area via rivers, streams and creeks. The water is then stored in a natural or artificial (manmade) barrier called a dam or reservoir. Dams are usually placed at the lower end of a valley.

Catchment areas are usually far away from towns or cities to lessen the chance of the water being polluted. There are laws which control human activities, such as farming and recreation in catchment areas and on dams to make sure that water supplies are kept potable.

Rivers or lakes

Town or community water supplies are sometimes drawn directly from nearby rivers or lakes.

Springs

These are found where underground water flows out of the ground naturally without the use of bores, wells or pumps.

Springs often occur towards the bottom of a hill or on sloping ground.

Rock catchment areas and rockholes

Sometimes large rocky outcrops contain low areas in which water is trapped. These low areas make good natural dams. Often a wall can be built to increase the amount of trapped water. 

Excavated dams

Excavated dams are made by scooping out soil to make a large shallow hole. These dams are sometimes placed at the bottom of a slope to aid water collection. However, this can only be done in areas where the soil will not allow the water to drain away very easily through the ground. For example, in clay soils.

Soils which do not allow water to drain away are called impervious.

If a community wants a dam in an area where the soil is not impervious this can still be done by digging the hole and lining it with clay or an impervious liner, such as concrete or heavy plastic. Excavated dams are often used by farmers to supply water to stock.

There is often a layer of water lying beneath the ground surface, trapped by an impervious layer of rock which will not allow it to drain away. The water may be close to ground level or it may be deep in the ground. This layer of water is called the water table.

When this water table is close to ground level the water may actually come to the surface and create a permanent wet area called a soak. This usually occurs in low lying areas or hollows.

Soaks are affected by changes in the depth of the water table. That is, if the water table drops then soaks may dry up. Some causes of this can be drought or overuse of ground water by people.

Rainwater tanks

The rainwater which falls on the roofs of houses is often collected using roof guttering leading through a pipe to a storage tank.

Note: Ehealth’s monograph ‘Guidance on use of Rainwater Tanks’ provides the most up-to-date information and advice on the range of potential hazards that can threaten rain water tank water quality. Environmental Health Practitioners are encouraged to use the guide when planning how to prevent these hazards from contaminating rainwater, straightforward monitoring and maintenance activities and, where necessary, corrective actions. The monograph can be found on the enHealth website or by using a search engine with the title of the monograph.

Bores and wells

These are holes drilled into the ground deep enough to find a permanent (long-lasting) body of water. A pipe runs down the hole into the water and a pump is used to get the water up to ground level. The water is then pumped to the community.

Artesian bores

Sometimes when a bore is sunk into a low lying area the water gushes out of the hole under its own pressure. This water is under pressure because it is part of an underground body of water much of which is at a higher level than the bore opening. This kind of bore is called an artesian bore.

A water supply taken directly from a bore or well is often called groundwater.

The water which comes from any of these sources may be salty, cloudy, smell unpleasant or have germs in it. Water of this kind would require special treatment to make it potable.

What is Rainwater Harvesting?

Water is, undoubtedly, the top natural resource you need for your home use. It’s glamorous to possess a stockpile of guns, gold, and jeweler, but without water, life might prove to be unbearable. Water shortages are sometimes inevitable, and so if you’re not prepared for the eventuality, you might find yourself between a rock and a hard place. The best and cheapest alternative to the traditional water supply systems is rainwater harvesting. However, to be able to harvest rainwater, you’ll need to install a rainwater harvesting system.

We all take water for granted. It is one of those natural resources that most people do not put a lot of thought into, but in order to continue enjoying that free supply of water for many more years, changes must be made. Rainwater harvesting is the process of collection of rainwater from surfaces on which rain falls, filtering it and storing it for multiple uses. Rainwater harvesting puts the supply of water back to normal levels. It is the collection and storage of water from surfaces that rain has fallen upon.

Rainwater harvesting is an innovative technique utilized to harvest rainwater from roofs and other above surfaces to be stored for later use. Rain harvested water can be used for garden and crop irrigation, watering livestock, laundry, and flushing toilets. However, you cannot use harvested rainwater for showering, bathroom sink or kitchen use because it’s not really fit for consumption.

In a normal scenario the rainwater is collected from roof buildings and then stored inside of a special tank. Rainwater harvesting systems are designed after assessing site conditions that include rainfall pattern, incident rainfall, subsurface strata and their storage characteristics. Rainwater harvesting is popular all across the world, although in countries that are very dry, such as Australia, it is even more popular.

Rainwater can be harvested and used by those in the city who have running city water just as well as it can be used by those in more rural towns where adequate water supply may be unavailable. It is simple to replace many things that you are using regular city water with rainwater and enjoy numerous benefits when you do. Not only it helps you to conserve water but can also help you to save energy as the need to maintain centralized water system can be bypassed.

If you are worried about your roof being dirty, put that fear to the side. Many different tools are available to help you easily clean your roof. Hiring a roofer to com provide you with a cleaning is another option that you will have available.

Individuals are driven to harvest rainwater because of a wide range of factors such as unpredictable weather patterns, enhanced costs of infrastructure and explosion of water consumption. On top of that, most businesses and homes are looking to embrace green practices to become efficient and a lot more self-reliant. In this case, rainwater presents the obvious choice because it is the easiest and quickest method to minimize water consumption. Most homeowners that have embraced this practice have reported a reduction of about 50% in water bills. On top of helping to reduce water bills, rainwater harvesting helps the environment a lot.

Benefits of Rainwater Harvesting

The collection of rainwater and harvesting it for everyday use has an ample number of exciting benefits. Let’s take a look and discover some of those benefits.

Provides backup source of water

There are many uncertainties in water supply systems. Droughts may lead to shortage of water. Destruction of water supply systems may occur at specific locations. Major repairs and maintenance in water companies happen sporadically. All these variables lead to unavailability of water in your home. So, installing rainwater harvesting system is the best course of action to continue enjoying water supply in case any of the above variables occur.

The collected rainwater can be used for many different purposes around the home. This includes laundry, washing dishes and more. This would prevent groundwater depletion and augment ground water table.

Ecological benefit

The ecological benefits of rainwater harvesting are immense. An activity like flushing the toilet, for instance, attributes to about 35% of home water usage. Add up the amount of water used to irrigate the lawn, do laundry, wash cars and the total amount water used is simply astronomical. For businesses, more so hospitality establishments that accommodate a big number of guests in a single location, require a lot of water to satisfy customers. Rainwater harvesting will simply help to fill this gap.

The ecological benefit rainwater harvesting systems bring is that there will be a significant reduction in the amount of water used from the mains. This, ideally, means that water companies will not have to artificially pump in water from rivers and lakes. This will help minimize the possibility of rivers drying up. Another great ecological benefit of rainwater harvesting systems is that they help reduced the load placed upon drainage systems, minimizing the impacts of flooding by funneling the runoff water into large tanks for recycling.

Easy to maintain

Rainwater harvesting systems are considerably easy to maintain since they are not utilized for drinking, cooking or other sensitive uses. This means that they will not need installation of purification systems, which are usually expensive.

Rainwater harvesting systems are cost effective, provide high quality water, reduce dependence on wells. The surplus rainwater can also be used to recharge ground water aquifer through artificial recharge techniques.

Reduces erosion and flooding around buildings

Most buildings that utilize rainwater harvesting systems have a built-in catchment area on top of the roof, which is capable of collecting vast amounts of water in case of rain storms. It helps to reduce soil erosion as by capturing rainwater, the flow of storm water is reduced which can also prevent urban flooding. If the water were not collected efficiently, it could have resulted in serious soil erosion and flooding around the house.

Requires low upfront capital investment

Installation of rainwater harvesting system is not that expensive, plus it’s a one-time installation, and that’s it. The only routine maintenance required is cleaning out the tank. You will probably hire an expert technician to install the system for you. The technician won’t quote a high price, plus he will offer free advice on the best rainwater system to buy. He will also help out when buying the system to ensure you get the best quality rainwater harvesting system. When you sum up the overall cost of installing the system, you’ll find that it’s actually manageable.

Once you begin using rainwater you will also appreciate a reduced amount of water consumption in the home, thus all of your utility bills will greatly shrink in size

Rainwater Harvesting Methods

It is simple to collect rainwater from building roofs and numerous other sources. As long as you are ready and equipped with a couple of different items you have all that it takes to begin rainwater harvesting and enjoying naturally delicious, clean and useful water. Rainwater harvesting systems can be purchased complete from various home improvement stores. The cost of these systems will vary.

Take a look at some of the techniques of rainwater harvesting for yourself.

Rainwater barrels

Barrel installation is the cheapest and easiest way to start harvesting rainwater in your home. A barrel is simply installed underneath the downspout of the guttering so that rain falling on the roof is funneled into the barrel. Usually, the container will consist of a spigot under it to enable you draw water and irrigate your garden. Better still; a hose can be connected to the spigot or to a drip irrigation system.

Barrels are advantageous because they can effortlessly be sourced whether recycled or new. If you opt for the recycled barrel, make a point to know exactly what the barrel was used for in order to be sure that no chemical residues remain inside. If you reside in a mosquito infested area, make sure to include a lid for your barrel to mitigate the possibility of mosquitoes breeding in your barrel.

When winter month knocks, it is advisable to disconnect your barrel to prevent freezing and cracking. The major disadvantage to rain water barrels is that they have limited capacity; meaning prolonged rains would result in flooding. The barrels are easy to use and readily available for purchase at many locations, all at reasonable prices.

Dry system

This is a well-known method of rainwater harvesting. It’s basically an improvement to the rain water barrel technique in terms of size. A larger water storage container is situated just a few steps from the property. This container provides a much larger storage capacity compared to the barrel. The gutter is then diverted to channel water into the tank. It’s also easy to implement and relatively cheap. The name “dry” comes from the fact that the collection pipe dries up after any rainy day because it’s meant to empty into the top of tank. The dry system is ideal for areas with huge storms.

Wet system

The wet system is the exact opposite of the dry system. This is because the collection pipes are ever full of water since they are located underground. Here, numerous collection pipes are connected to multiple downspouts on the building and channeled to empty into the storage tank underground. When there is no rain, the level stays constant, and the pipes are always full. Due to the ever availability of water inside the pipes, it is recommended that they be watertight to mitigate the possibility of leaking into the soil. The underground piping makes it relatively expensive to install compared to the dry and wet systems.

Green roof

This method of rainwater harvesting literally cuts out the middleman. Instead of directing rainwater for storage in the tank and then channel it to the garden; you could install a green roof on your house to enable plants use the water instantly. But you have to lay down a lining for your roof’s protection and include a drainage system to take care of the runoffs. Installing garden beds with plants that require low maintenance is the surefire way of maximizing your plot’s productive space and leveraging the rainwater where it falls. Also, installing a green roof will add insulation to your house and cushion your roof from damage.

If you prefer you can create your own barrels for rainwater harvesting. Just a few components like Catchment area, conveyance system, first rain separator, filter unit, storage, delivery system, usage, recharge and supplies are needed to create your own barrel.

You will need to follow the instructions included with your rainwater harvesting kit to set things up and begin collection of the rainwater. For a DIY job, there are many resources available to you on the internet at no charge. You can definitely take advantage of the information whenever you need to and create your own rainwater harvesting system.

Conclusion

Rainwater harvesting is something that thousands of families across the world participate in, and you could be the next to enjoy the multitude of benefits offered with rainwater harvesting. It is an easy, simple and worthwhile process, so it is only in your best interest to take a look at rainwater harvesting and its benefits to your home. You may discover many surprises and things that you did not know along the way!

Advantages of Rainwater Harvesting

1. Easy to Maintain: Utilizing the rainwater harvesting system  provides certain advantages to the community. First of all, harvesting rainwater allows us to better utilize an energy resource. It is important to do so since drinking water is not easily renewable and it helps in reducing wastage. Systems for the collection of rainwater are based on simple technology.

The overall cost of their installation and operation is much lesser than that of water purifying or pumping systems. Maintenance requires little time and energy. The result is the collection of water that can be used in substantial ways even without purification.

2. Reducing Water Bills: Water collected in the rainwater harvesting system  can be put to use for several non-drinking functions as well. For many families and small businesses, this leads to a large reduction in their utilities bill. On an industrial scale, harvesting rainwater can provide the needed amounts of water for many operations to take place smoothly without having to deplete the nearby water sources.

It also lessens the burden of soil erosion in a number of areas, allowing the land to thrive once again. In fact, it can also be stored in cisterns for use during times when water supplies are at an all time low.

3. Suitable for Irrigation: As such, there is little requirement for building new infrastructure for the rainwater harvesting system. Most rooftops act as a workable catchment area, which can be linked to the harvesting system. This also lessens the impact on the environment by reducing use of fuel based machines.

Rainwater is free from many chemicals found in ground water, making it suitable for irrigation and watering gardens. In fact, storing large reservoirs of harvested water is a great idea for areas where forest fires and bush fires are common during summer months.

4. Reduces Demand on Ground Water: With increase in population, the demand for water is also continuously increasing. The end result is that many residential colonies and industries are extracting ground water to fulfill their daily demands. This has led to depletion of ground water which has gone to significant low level in some areas where there is huge water scarcity.
5. Reduces Floods and Soil Erosion: During rainy season, rainwater is collected in large storage tanks which also helps in reducing floods in some low lying areas. Apart from this, it also helps in reducing soil erosion and contamination of surface water with pesticides and fertilizers from rainwater run-off which results in cleaner lakes and ponds.
6. Can be Used for Several Non-drinking Purposes: Rainwater when collected can be used for several non-drinking functions including flushing toilets, washing clothes, watering the garden, washing cars etc. It is unnecessary to use pure drinking water if all we need to use it for some other purpose rather than drinking.

Water is life for all but this water is polluting day by day in severe condition. So it can be said that our life (water) is not safe now. We are in crisis period. Water pollution is a major serious problem for all over the world. It affects drinking water, rivers, lakes and oceans all over the world. It consequently harms the health and wellbeing of human life and the natural environment.

Effect of water pollution

Effects of water pollution: Polluted water has effects on both human and aquatic life.

1. Effect of water pollution on human health

Chemicals in water that affect human health: Some of the chemicals affecting human health are the presence of heavy metals such as Fluoride, Arsenic, Lead, Cadmium, Mercury, petrochemicals, chlorinated solvents, pesticides and nitrates. Fluoride in water is essential for protection against dental caries and weakening of the bones. Concentration below 0.5 mg/l causes dental caries and mottling of teeth but exposure to higher levels above 0.5 mg/l for 5-6 years may lead to adverse effect on human health leading to a condition called fluorosis. Arsenic is a very toxic chemical that reaches the water naturally or from wastewater of tanneries, ceramic industry, chemical factories and from insecticides such as lead arsenate, effluents from fertilizers factories and from fumes coming out from burning of coal and petroleum. Arsenic is highly dangerous for human health causing respiratory cancer, arsenic skin lesion from contaminated drinking water in some districts of West Bengal. Long exposure leads to bladder and lungs cancer. Lead is contaminated in the drinking water source from pipes, fitting, solder, household plumbing systems. In the human beings, it affects the blood, central nervous system and the kidneys. Child and pregnant women are mostly prone to lead exposure. Mercury is used in industries such as smelters, manufacturer of batteries, thermometers, pesticides, fungicides etc. The best known example of Mercury pollution in the oceans took place in 1938 when a Japanese factory discharged a significant amount of mercury into Minamata Bay, by contaminating the fish stocks there. It took several years to show its effects. By that time, many local people had eaten the fish and around 2000 were poisoned,hundreds of people were left dead and disabled (Akio, 1992) and the cause for death was named as “Minamata disease” due to consumption of fish containing methyl mercury. It causes chromosomal aberrations and neurological damages to human. Mercury shows biological magnification in aquatic ecosystems. Cadmium reaches human body through food crop from soil irrigated by affected effluents. Friberg et al. (1974) noted that long term consumption of rice from affected fields by the people living in areas contaminated by cadmium in regions of Japan, resulted into many renal diseases like “itai-itai disease”, nephritis and nephrosis. 

Water borne disease: Microorganisms play a major role in water quality and the microorganisms that are concerned with water borne diseases are Salmonella sp., Shigella sp., Escherichia coli and Vibrio cholera (Adetunde and Glover, 2010). All these cause typhoid fever, diarrhoea, dysentery, gastroenteritis and cholera. The most dangerous form of water pollution occurs when faeces enter the water supply. Many diseases are perpetuated by the faecal-oral route of transmission in which the pathogens are shed only in human faeces. Presence of faecal coliforms of E. coli is used as an indicator for the presence of any of these water borne pathogens. Larry (2006) suggested that groundwater contamination is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily, and the majority of them being children under 5 years old. In recent years, the widespread reports of pollutants in groundwater have increased public concern about the quality of groundwater. Children are generally more vulnerable to intestinal pathogens and it has been reported that about 1.1 million children die every year due to diarrhoeal diseases.

2. Effect of water pollution on plants

The following are the effects of water pollution on plants:

1. Effects of acid deposition: Many of the gases from acid, aerosols and other acidic substances released into the atmosphere from industrial or domestic sources of combustion from fossil fuels finally fall down to ground and reach the water bodies along with run-off rainwater from polluted soil surfaces thereby causing acidification of water bodies by lowering its pH . In many countries chemical substances like sulphates, nitrates and chloride have been reported to make water bodies such as lakes, river and ponds acidic.
2. Nutrient deficiency in aquatic ecosystem: Population of decomposing microorganisms like bacteria and fungi decline in acidified water which in turn reduces the rate of decomposition of organic matter affecting the nutrient cycling. The critical pH for most of the aquatic species is 6.0. The diversity of species decline below this pH whereas the number and abundance of acid tolerant species increases. Proliferation of filamentous algae rapidly forms a thick mat at the initial phase of the acidification of water. Cladophora is highly acid tolerant species and is abundant in acidic freshwater bodies. Macrophytes are generally absent in acidic water as their roots are generally affected in such water resulting in poor plant growth. Potamogeton pectinatus is found in acidified water. It is observed that plants with deep roots and rhizomes are less affected while plants with short root systems are severely affected in acidic water.

iii. Effects of organic matter deposition: Organic matter from dead and decaying materials of plants and animals is deposited directly from sewage discharges and washed along with rainwater into water bodies causing increase in decomposers / microbes such as aerobic and anaerobic bacteria. Rapid decomposition of organic matter increase nutrient availability in water favouring the luxuriant growth of planktonic green and blue-green algal bloom. In addition many of the macrophytes like Salvinia, Azolla,Eicchhornia etc. grow rapidly causing reduced penetration of light into deeper layer of water body with gradual decline of the submerged flora . This condition results in reducing the dissolved Oxygen and increase in the biological oxygen demand (B.O.D). 

1. Effects of detergent deposition: Detergents from domestic and industrial uses wash down into water bodies causing serious effects on plants. Detergents contain high phosphates which results in phosphate-enrichment of water. Phosphates enter the plants through roots or surface absorption causing retarded growth of plants, elongation of roots, carbon-dioxide fixation, photosynthesis, cation uptake,pollen germination and growth of pollen tubes, destruction of chlorophylls and cell membranes and denaturation of proteins causing enzyme inhibition in various metabolic processes.
2. Effects of agricultural chemicals: Chemicals from fertilizers, pesticides, insecticides,herbicides etc. applied to crops in excess are washed away with rainwater as runoff, then enter into soil and finally arrive at the water bodies. Chemicals from fertilizers result in eutrophication by enrichments of nutrients. Ammonium from fertilizers is acidic in nature causing acidification of water. Similarly pesticides, herbicides and insecticides also cause change in pH of the water bodies. Most common effect of these substances is the reduction in photosynthetic rate. Some may uncouple oxidative phosphorylation or inhibit nitrate reductase enzyme. The uptake and bioaccumulation capacities of these substances are great in macrophytic plants due to their low solubility in water.

1. Effects of industrial wastes: Effluents from industries contain various organic and inorganic waste products. Fly ash form thick floating cover over the water thereby reducing the penetration of light into deeper layers of water bodies. Fly ash increases the alkalinity of water and cause reduced uptake of essential bases leading to death of aquatic plants. Liquid organic effluents change the pH of water and the specific toxicity effects on the aquatic plants vary depending on their chemical composition. There may be synergistic, additive or antagonistic interactions between metals with respect to their effects on plants however these effects are reduced in hard and buffered freshwater bodies.

vii. Effects of silt deposition: Deposition of silt in water bodies occurs as a result of erosion carrying silt laden water and due to flood. It increases the turbidity of water and reduces light penetration in deep water causing decline in abundance of submerged plants. Siltation inhibits the growth of aquatic plants. Abundance of phytoplankton is affected due to reduction in surface exchange of gases and nutrients. Plants that are tolerant to turbidity are abundant followed by those that are intermediate and the least tolerant species. Plants such as Polygonum, Sagittaria etc. are found to grow in dominance.

viii. Effects of oil spillage: Oil pollution due to spillage of oil tankers and storage containers prevents oxygenation of water and depletes the oxygen content of the water body by reducing light transmission inhibiting the growth of planktons and photosynthesis in macrophytes.

1. Effects of thermal pollution: The release of heated water into water bodies from the thermal power plants has an adverse effect on the aquatic life. It reduces the activity of aerobic decomposers due to oxygen depletion because of high temperature. With decreased organic matter decomposition , the availability of nutrients in the water bodies is jeopardised. Aquatic plants show reduced photosynthesis rate due to inhibition of enzyme activity with increased temperature. Primary productivity and diversity of aquatic plant species decline because of increased temperature of water bodies as a result of thermal pollution.

1. Effect of nutrient enrichment: Nutrient enrichment in aquatic water bodies leads to eutrophication which is a process whereby water bodies receive excess inorganic nutrients, especially N and P, stimulating excessive growth of plants and algae. Eutrophication can happen naturally in the course of normal succession of some freshwater ecosystems. However, when the nutrient enrichment is due to the activities of humans, it is referred to as “cultural eutrophication”, where the rate of nutrient enrichment is greatly intensified. Eutrophication was recognized as a pollution problem in North American lakes and reservoirs in the mid 20th century (Rohde, 1969). Plants must take in nutrients from the surrounding environment in order to grow. Nitrogen and phosphorous, in particular, encourage growth because they stimulate photosynthesis. This is why they are common ingredients in plant fertilizers. When agricultural runoff pollutes waterways with nitrogen and phosphorus rich fertilizers, the nutrient-enriched waters often paves way to algal bloom leading to eutrophication.The result is oxygen depletion and dying of fishes due to suffocation.
2. Phytotoxicity effects on plants: When chemical pollutants build up in aquatic or terrestrial environments, plants can absorb these chemicals through their roots. Phytotoxicity occurs when toxic chemicals poison plants. The symptoms of phytotoxicity on plants include poor growth, dying seedlings and dead spots on leaves. For example, mercury poisoning which many people associate with fish can also affect aquatic plants, as mercury compounds build up in plant roots and bodies result in bioaccumulation.As animals feed on polluted food the increasing levels of mercury is built up through food chain.

Control of Water Pollution

The key challenges to better management of the water quality in India comprise of temporal and spatial variation of rainfall, uneven geographic distribution of surface water resources,persistent droughts, overuse of groundwater and contamination, drainage and salinisation and water quality problems due to treated, partially treated and untreated wastewater from urban settlements, industrial establishments and runoff from irrigation sector besides poor management of municipal solid waste and animal dung in rural areas. Some of the control measures are given below;

1. The Ganga Action Plan and the National River Action Plan are being implemented for addressing the task of trapping, diversion and treatment of municipal wastewater.
2. In most parts of the country, wastewater from domestic sources is hardly treated, due to inadequate sanitation facilities. This wastewater, containing highly organic pollutant load, finds its way into surface and groundwater courses near the vicinity of human habitation from where further water is drawn for use. Considerable investments should be done to install the treatment systems.
3. All towns and cities must have Sewage Treatment Plants (STPs) that clean up the

sewage effluents.

4. Improper use of fertilizers, herbicides and pesticides in farming should be stopped and

organic methods of farming should be adopted. Cropping practices in riparian zone should be banned to protect the riparian vegetation growing there.

5. The water quality management in India is accomplished under the provision of Water (Prevention and Control of Pollution) Act, 1974 that was amended in 1988. The basic objective of this Act is to maintain and restore the wholesomeness of national aquatic

resources by prevention and control of pollution. The Water (Prevention and Control of Pollution) Cess Act was enacted in 1977, to provide for the levy and collection of access on water consumed by persons operating and carrying on certain types of industrial activities.

6. The Central Pollution Control Board (CPCB) has established a network of monitoring

stations on aquatic resources across the country. The water quality monitoring and its

management are governed at state/union territory level in India. The network covers 28 states

and 6 Union Territories (CPCB Report, 2013). Water quality monitoring is therefore an

imperative prerequisite in order to assess the extent of maintenance and restoration of water

bodies.

7. There should be ban on washing of clothes and laundry alongside the river bank.
8. Industries should install Effluent Treatment Plant (ETP) to control the pollution at source.
9. For the agricultural sector, water and electricity for irrigation are subsidized for political reasons. This leads to wasteful flood irrigation rather than adoption of more optimal practices such as sprinkler and drip irrigation. Optimized irrigation, cropping patterns and farming practices should be encouraged for judicious use of water.

10. With rapid industrialization and urbanization, the water requirement for energy and industrial use is estimated to rise to about 18% . Poor environmental management systems, especially in industries such as thermal power stations, chemicals, metals and minerals, leather processing and sugar mills, have led to discharge of highly toxic and organic wastewater. This has resulted in pollution of the surface and groundwater sources from which water is also drawn for irrigation and domestic purpose. The enforcement of regulations regarding discharge of industrial wastewater and limits to extraction of groundwater needs to be considerably strengthened, while more incentives are required for promoting waste water reuse and recycling.
11. Religious practices that pollute river water by dumping colourful paints of idols containing harmful synthetic chemicals should be stopped.
12. Rain water harvesting should be practiced to prevent the depletion of water table.
13. Making people aware of the problem is the first step to prevent water pollution. Hence, importance of water and pollution prevention measures should be a part of awareness and education programme.
14. Polluter pays principle should be adopted so that the polluters will be the first people to suffer by way of paying the cost for the pollution. Ultimately, the polluter pays principle should be designed to prevent people from polluting and making them behave in an environmentally responsible manner.
15. As riparian vegetation helps in making the river water clean because of the multiple

functions, to prevent people from felling and clearing down of riparian forest zones for road construction, agricultural practices, recreational and tourism , sand mining, quarrying and clay mining etc. community should play a regulatory role.

 Water conservation refers to reducing the usage of water and recycling of waste water for different purposes like domestic usage, industries, agriculture etc.

Efforts have been made to collect water by building dams, reservoirs and digging wells; some countries have also tried to recycle and desalinate sea water. 

The method of recharging ground water by harvesting rainwater is gaining importance in many cities.

In the forests, water seeps gently into the ground due to vegetation cover. This groundwater in turn feeds wells, lakes, and rivers. Protecting forests means protecting water ‘catchments’. In ancient India, people worshipped Nature and one of them was Water.

REF PDF

http://waterandme.tamu.edu/ConservingWater/conservingwater.pdf

Importance of Water Conservation

Cycle of nature is completely depends on water. Until the water evaporates and mix into air there will be no rain on earth which causes damaged crops and worst situation of drought all over the place. Every living being whether they are human, animal or plants requires water to survive here. Not only for drinking water is essential for domestic use like washing, cleaning, moping, cooking and even for agriculture and industrial use including power plant.

In many areas of India water is so less in quantity even fresh water is about to nil. In those places people have to either too much charge or to go hundreds of miles far to get potable water for their daily use. Water is so important constituent for all living beings that if we still not find the solution for conserving it, survival on earth would be in danger.

Definition of Dam

Dam is a manmade barrier constructed to contain flow of water built across a river, lake, sea forming a reservoir behind it. They are mostly constructed from earth, natural materials, concrete & rocks.

Types of dams:-

Arch dams – Arch dams are made from concrete. They are curved in the shape of an arch, with the top of the arch pointing back into the water. Arch dams are usually constructed in narrow, steep valleys. They like all dams need good rock for their foundations, to resist the force of water on the dam. An arch shape is used for resisting the pushing force of the flowing water behind the dam.

Buttress dams – These dams are made from concrete & masonry or both. The watertight upstream side supported is by triangular shaped walls, called buttresses. The buttresses are spaced at regular intervals on the downstream side. They resist the force of the reservoir water trying to push the dam over.

The buttress dam was developed from the idea of the gravity dam, except that buttress dam uses a lot less because there are a lot of empty spaces between the buttress dams. Like gravity dams, they are made to suit to both narrow and wide valleys and they must be constructed on stable rock.

Since 1945, 14 buttress dams have been constructed in the UK, mainly for hydroelectric schemes in Scotland.

Cross-section through gravity dam (http://www.britishdams.org/about_dams/gravity.htm)

Gravity dams -A gravity dam is made from concrete or masonry, or sometimes both. It is called a gravity dam because gravity is the force that holds it down to the ground stopping the water in the reservoir pushing it over.

http://www.geographynotes.com/essay/dams-essay/essay-on-dams-india-geology/5832

USES OF DAMS

Water supply -This water is used to supply water to homes and factories. Reservoirs are designed in such a way to store the rain that falls during the rainier parts of the year, so that there is a continuous supply of water for the drier period

Hydroelectricity- Waters in the reservoirs could be used to store water to feed hydroelectric power stations. Hydroelectric power is produced by using the potential energy from falling water to drive water turbines that in turn, turn electric generators. The reservoir water is stored at a height higher than the turbines, which are in the power station. Sometimes, the power station is directly in front of a dam, and pipes through the dam feed water directly to the turbines. In some other cases, the power station is downhill from the reservoir, and the water is fed to it through long pipes or tunnels called penstocks.

Flood control – A reservoir can be used to control the amount of water flowing in a river after heavy rain or snow fall. The water level in the reservoir is kept low during the wetter periods of the year. When heavy rain occurs, it is gated by the dam and held in the reservoir like a collecting tank. When the reservoir gets too full, the floodwater can be passed downstream over a spillway.

Sometimes, floodgates are used on top of spillways, and they can be fully or partly opened to control the amount of water let out into the river downstream. If dam weren’t there the water level in rivers can rise dramatically. Sometimes, the water flows over riverbanks or walls causing flooding of farmland, property, and in the worst cases, loss of life.

Irrigation-Plants grow naturally on fertile soil that is watered by rain. However, in different regions of the world where the climate is very dry for some parts of the year, the soil becomes so dry that it restricts the growth of vegetation. This problem can be overcome by irrigation, a man-made system for watering the land. As water is released through spillway into downstream and to the drier parts

Navigation -The construction of a dam across a river forms a reservoir that holds water raises the water level upstream, , and it slows down its rate of flow. This improves the navigation conditions upstream of the dam for ships and boats. Dangerous areas of rocks and sandbanks, previously in shallow water, become well covered, and rapids in the river disappear. Also, water from the reservoir can be released into the river downstream during the drier seasons of the year to make sure that it is deep enough for navigation all the year round.

RAIN WATER HARVESTING

Rainwater harvesting is the collection and storage of rain water in the natural resources or artificially designed resources to prevent water runoff and fulfill the lack of water in future. The quantity of water harvesting is affected by the number of factors like frequency of rainfall, quantity of rainfall, way of collecting rain water, and size of resources to collect water. The ground water level is getting depleted day by day due to various reasons like deforestation and ecological imbalance. Increasing level of urbanization and industrialization constantly increases the demand of water supply especially in the urban areas. It results in the overuse of ground water and thus going low level. The risk of water scarcity in the future has been increased to a great extent and can be life threatening if some effective solutions are not followed.

Water harvesting is very helpful and fulfill various need like recharging the ground water level, reduces electricity bill spend in supplying water and provide easy water supply anytime when required. It is estimated that 1 meter rise in the water level saves around 0.4 KWH of electricity.

Why Rain Water Harvesting is Necessary:

Rain water harvesting is very necessary to be practiced by the people in all regions. It is good to reduce the fear of water scarcity in the future. Following are the points proving the fact that why rain water harvesting is necessary:

• Surface water cannot fulfill the demand of water for various purposes.
• Everyone depend on the ground water for their every need.
• Deforestation, rapid urbanization, rain water infiltration to the sub-soil, etc reasons are continuously decreasing the level of ground water.
• Rain water conservation maintains the level of water in natural water resources.
• It reduces the chance of flooding of water on the roads, reduces the risk of soil erosion and improves the quality of water.

Following are main techniques of rain water harvesting:

• Collecting rainwater to the surface for future use.
• Recharging the ground water.

Collecting rain water to the surface is very effective and traditional technique. It can be done using small ponds, underground tanks, dams, weirs etc. However, ground water recharging technique is a new concept of harvesting. It can be done using dug wells, pits, trenches, hand pumps, recharge wells, recharge shafts, recharge lateral shafts with bore wells, spreading technique (means spread of water to the stream, nala, etc).

Goals of Water Conservation

 The goals of water conservation efforts include as follows: Sustainability. To ensure availability for future generations, the withdrawal of fresh water from an ecosystem should not exceed its natural replacement rate. Energy conservation. Water pumping, delivery, and wastewater treatment facilities consume a significant amount of energy. In some regions of the world over 15% of total electricity consumption is devoted to water management. Habitat conservation. Minimizing human water use helps to preserve fresh water habitats for local wildlife and migrating water flow, as well as reducing the need to build new dams and other water diversion infrastructure.

You can gather some more information by looking at the videos which is given below:-

Short film on saving water

https://www.youtube.com/watch?v=i-wSR0socac The Magic Pipe 

https://www.youtube.com/watch?v=7kajNhXvYhU

Water Pollution Documentary

https://www.youtube.com/watch?v=h198sZXP7fU