Friday, April 30, 2010

Water Management

CURRENT FORMS OF MANAGEMENT
The individual and the community can help minimize water pollution by simple housekeeping and management practices thus the amount of waste generated can be minimized.
Conservation - In the forests, water seeps gently into the ground as vegetation breaks the fall. This groundwater in turn feeds wells, lakes, and rivers. Protecting forests means protecting water 'catchments'.
Over the years rising populations, growing industrialization, and expanding agriculture have removed forests and pushed up the demand for water. Water is collected by building dams and reservoirs and digging wells. Some countries have also tried to recycle and desalinate (remove salts) water. Water conservation is the need of the hour. The idea of ground water recharging by harvesting rainwater is gaining importance in many cities.
Some ancient methods of water conservation - The Indus Valley Civilization, that flourished about 5,000 years ago, had one of the most sophisticated urban water supply and sewage systems in the world. The people were well acquainted with hygiene can be seen from the covered drains running beneath the streets of the ruins at both Mohenjodaro, Harappa and the well-planned city of Dholavira, on Khadir Bet, a low plateau in the Rann in Gujarat. One of the oldest water harvesting systems is found about 130 km from Pune along Naneghat in the Western Ghats. A large number of tanks were cut in the rocks to provide drinking water to tradesmen who used to travel along this ancient trade route. Each fort in the area had its own water harvesting and storage system in the form of rock-cut cisterns, ponds, tanks and wells that are still in use today. A large number of forts like Raigad had tanks that supplied water. In ancient times, houses in parts of western Rajasthan were built so that each had a rooftop water harvesting system. Rainwater from these rooftops was directed into underground tanks. This system can be seen even today in all the forts, palaces and houses of the region. Infact underground baked earthen pipes and tunnels to maintain the flow of water and to transport it to distant places, are still functional at Burhanpur in Madhya Pradesh, Golkunda and Bijapur in Karnataka, and Aurangabad in Maharashtra. `Pookars' or ponds were dug and maintained in each village and town.
Another important step in the direction of finding solutions to issues of water and environmental conservation is to change people's attitudes and habits this includes each one of us. Conserve water because it is the right thing to do.
You can store water in a variety of ways. A simple method is to place a drum on a raised platform directly under the rainwater collection source. You can also collect water in a bucket during the rainy season.
What you can do to conserve water 
  • Use only as much water as you require.
  • Close the taps well after use. 
  • While brushing your teeth do not leave the tap running, open it only when you require it. 
  • See that there are no leaking taps. Get a plumber to come in and seal all leaks. 
  • Use a washing machine that does not consume too much water. 
  • Do not leave the taps running while washing dishes and clothes. 
  • Install small shower heads to reduce the flow of the water. 
  • After washing vegetables and fruits use it to water flowers and ornamental potted plants. 
  • At the end of the day any water left should not be thrown away but poured into some plants.
Rainwater harvesting - Cherrapunji was famous as it received the highest volume of rainfall in the world. It still does but experiences acute water shortages due to extensive deforestation and improper methods of conserving rainwater. There has been extensive soil erosion and often one can see stretches of hillside devoid of trees and greenery. People have to walk long distances to collect water. In the areas around the River Ruparel in Rajasthan not even half the rainfall is received as compared to Cherrapunji, yet the story is different due to proper water conservation and management resulting in more water being available than in Cherrapunji. The water level in the river declined due to extensive deforestation and agricultural activities along the banks and, by the 1980s, a drought-like situation spread. The villagers built johads (round ponds) and dams to hold back rainwater. Gradually, water returned as proper methods of conserving and harvesting rainwater were followed. The river revived and transformed the ecology here strengthening the relationship with their natural environment.
In urban centers, the construction of houses, footpaths, roads and drainage system has left little exposed earth for water to soak in. Water harvesting has become a very popular method of conserving water especially in the urban areas. Rainwater harvesting essentially means collecting rainwater on the roofs of building and storing it underground for later use. Not only does this recharging arrest groundwater depletion, it also raises the declining water table and can help augment water supply. Rainwater harvesting and artificial recharging are becoming very important issues. It is essential to stop the decline in groundwater levels, arrest sea-water ingress, i.e. prevent sea-water from moving landward, and conserve surface water run-off during the rainy season. Town planners and civic authority in many cities in India are introducing bylaws making rainwater harvesting compulsory in all new structures. All you need for a water harvesting system is rain, and a place to collect it! Typically, rain is collected on rooftops and other surfaces, and the water is carried down to where it can be used immediately or stored. You can direct water run-off from this surface to plants, trees or lawns or even to the aquifer.
Benefits of rainwater harvesting
  • Increases water availability
  • Checks the declining water table
  • Is environmentally friendly
  • Improves the quality of groundwater through the dilution of fluoride, nitrate, and salinity 
  • Prevents soil erosion and flooding especially in urban areas
Agriculture - Conservation of water in the agricultural sector is essential since water is necessary for the growth of plants and crops. A depleting water table and a rise in salinity due to overuse of chemical fertilizers and pesticides has made matters serious. Various methods of water harvesting and recharging have been and are being applied all over the world to tackle the problem. In areas where rainfall is low and water is scarce, the local people have used simple techniques that are suited to their region and reduce the demand for water.
In India's arid and semi-arid areas, the 'tank' system is traditionally the backbone of agricultural production. Tanks are constructed either by bunding or by excavating the ground and collecting rainwater.
Rajasthan, located in the Great Indian Desert, receives hardly any rainfall, but people have adapted to the harsh conditions by collecting whatever rain falls. Large bunds to create reservoirs known as khadin, dams called johads, tanks, and other methods were applied to check water flow and accumulate run-off. At the end of the monsoon season, water from these structures was used to cultivate crops. Similar systems were developed in other parts of the country. These are known by various local names ¾ jal talais in Uttar Pradesh, the haveli system in Madhya Pradesh, ahar in Bihar, and so on.
Reducing water demand - Simple techniques can be used to reduce the demand for water. The underlying principle is that only part of the rainfall or irrigation water is taken up by plants, the rest percolates into the deep groundwater, or is lost by evaporation from the surface. Therefore, by improving the efficiency of water use, and by reducing its loss due to evaporation, we can reduce water demand.
There are numerous methods to reduce such losses and to improve soil moisture. Some of them are listed below.
  • Mulching, i.e., the application of organic or inorganic material such as plant debris, compost, etc., slows down the surface run-off, improves the soil moisture, reduces evaporation losses and improves soil fertility. 
  • Soil covered by crops, slows down run-off and minimizes evaporation losses. Hence, fields should not be left bare for long periods of time.
  • Ploughing helps to move the soil around. As a consequence it retains more water thereby reducing evaporation. 
  • Shelter belts of trees and bushes along the edge of agricultural fields slow down the wind speed and reduce evaporation and erosion.
  • Planting of trees, grass, and bushes breaks the force of rain and helps rainwater penetrate the soil.
  • Fog and dew contain substantial amounts of water that can be used directly by adapted plant species. Artificial surfaces such as netting-surfaced traps or polyethylene sheets can be exposed to fog and dew. The resulting water can be used for crops. 
  • Contour farming is adopted in hilly areas and in lowland areas for paddy fields. Farmers recognize the efficiency of contour-based systems for conserving soil and water. 
  • Salt-resistant varieties of crops have also been developed recently. Because these grow in saline areas, overall agricultural productivity is increased without making additional demands on freshwater sources. Thus, this is a good water conservation strategy.
  • Transfer of water from surplus areas to deficit areas by inter-linking water systems through canals, etc.
  • Desalination technologies such as distillation, electrodialysis and reverse osmosis are available. 
  • Use of efficient watering systems such as drip irrigation and sprinklers will reduce the water consumption by plants.
A MUST TO DO

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