Today in almost all spheres of human activity more water is drawn than what is actually needed. Due to carelessness much of it is wasted and allowed to flow out in an impure state. At many places enough clean water is no longer available.
The rapid rise in demand for fresh water is naturally a result of an equally rapid growth in the number of consumers. But there are many other causes as well which have contributed significantly to the wastage and degeneration of fresh water.
For example, about 40 per cent of the world’s population lives in arid or semi-arid regions. These people spend lot of energy, time and effort in obtaining water for their domestic and agricultural uses.
To meet the needs of huge population, surface waters, i.e., ponds, lakes, rivers, streams, etc., are overdrawn. Due to over use of surface water, the nearby wetlands may dry up.
When more ground water is removed for human use than can be recycled by rainfall or snow- melt, the ground water may also dry out.
However, everywhere we tend to use more water than is actually needed. A little care can result in substantial savings and longer life for our resource base or else, the water thus saved can be diverted to regions where there is shortage.
Excessive irrigation in arid and semi-arid regions can cause salt accumulation in the soil, due to which crop productivity will decline.
On the other hand, the continuous depletion of ground water along the coastal regions often leads to the movement of saline sea water into fresh water wells, spoiling the quality of water. Estuaries become more saline and consequently less productive when surface waters are over drawn.
Addition of wastes and sewage causes the water body to become exceedingly rich in plant nutrients. Blooms of algae and other organisms appear and make the water useless for human purposes.
The entire biomass may suddenly die and start decomposing causing several other problems. Organically rich waters also support a population of many pathogenic organisms and vectors which transfer diseases from one individual to another.
Heavy rainfall results in rapid run-off from areas having exposed soil, particularly on mountain slopes. This causes soil erosion which results in heavy floods. Uncontrolled soil erosion is the main cause of sedimentation of water ways which causes harm to fisheries.
Now-a-days, pressure of demand on underground water resources has gone up considerably. Every year more and more water is drawn up from sub-surface layers whereas recharging of underground waters has been slowed down. Massive deforestation has caused disappearance of plant cover over a large area of land surface.
In absence of plant cover most of the rain water flows down quickly in streams and rivers. Little of it percolates down to sub-surface layers to recharge the ground water stock. With rapidly flowing waters considerable amount of top soil is lost with torrential flow of water. In a number of localities where underground water is regularly drawn, the water table is receding deeper, thus output exceeds the input.
Conservation and Management of Water:
As we know, water is the basic need of living organisms. An acute crisis of water is expected to follow in some regions of the world, particularly in our country. The shortage of water shall make many localities barren, dry and devoid of life. Fertile land will convert into deserts. Conservation of fresh water is therefore, an absolute necessity of today.
A number of steps are being undertaken to minimise wastage of fresh water resources and to make more efficient use of the available water.
Main approaches for conservation of water are as follows:
(i) Reducing agricultural water wastage by increasing efficiency of irrigation.
(ii) Reducing water wastage in industry by recycling the used water.
(iii) Reducing domestic water wastage by constructing waste water treatment plants and recycling the treated water.
(iv) Rainwater harvesting by using practices to store rainwater and recharge groundwater.
(v) Afforestation and protection of water sheds to improve water economy.
(vi) Reducing pollution and recycling of water.
(vii) By development of an efficient distribution system of water.
(viii) By enhancement of surface water storage capacity.
(ix) By improvement of underground water storage capacity.
(x) By adopting water economy.
Main approaches for management of water are as follows:
(i) Construction of dams and ‘reservoirs to regulate year-round supply of water. They are also helpful in controlling flood and generating electricity.
(ii) Desalinisation of sea water and saline groundwater, making it fit for drinking and agricultural purposes. Desalinisation plants are already under operation in Middle East countries.
(iii) Diversion of water and bodies (e.g., through canals) to increase the natural supply of water to a particular area.
(iv) Regular dredging and desiltation of water bodies.
Reforms in the Rural Drinking Water Sector were adopted in 1999 and also a few projects were launched as pilots.
They were intended to be implemented during the Ninth Five Year Plan and with the experience gained there on, the reform initiatives were to be firmed up and scaled up during the Tenth Plan period for adopting the demand responsive strategy and also for institutionalizing community participation for the sustainability of drinking water supply system and sources in rural areas.
On 15.12.2002, the reform initiative in the Rural Drinking Water Sector was scaled up throughout the country by launching the Swajaldhara by the Hon’ble Prime Minister of India.