1.Make a working model of Rehat.
2. Illustrate some ideas to conserve ground water.
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Answer:
Author: Shikha Shah
Many of us who live in big cities enjoy a carefree lifestyle with 24 hours of running taps, swimming pools, Jacuzzis and decorative fountains. Sheltered by this layer of comfort, we remain unaware of the impact of these water-intensive activities on our environment. Rapid urbanization and water pollution have widened the supply and demand gap, putting enormous pressure on the quality of surface and groundwater bodies in India. Clean water is destined to become one of the rarest commodities soon, if the general public is not educated about the significance of storing, recycling and reusing water.
Around 83% of available fresh water in India is used for agriculture. Rainfall being the primary source of freshwater, the concept behind conserving water is to harvest it when it falls and wherever it falls. The importance of storing rainwater through different techniques can be understood by an example of the desert city of Jaisalmer in Rajasthan which is water self-sufficient despite experiencing meager rainfall as against Cherrapunji, which is blessed with the highest rainfall in the world, but still faces water shortage due to lack of water conservation methods.
Water Conservation Methods in India from Past to Present
Since ages, people across different regions of India, have experienced either excess or scarce water due to varied rainfall and land topography. Yet, they have managed to irrigate their agricultural fields using localized water harvesting methods. Their traditional ways, though less popular, are still in use and efficient. They are enriched with the knowledge to manage water in communal ways. Let’s learn about a few traditional water conservation methods in India used by our illiterate yet successful water managers in India:
Katta
Katta - Traditional Water Conservation India
Katta is a temporary structure made by binding mud and loose stones available locally. Built across small streams and rivers, this stone bund slows the flow of water, and stores a large amount (depending upon its height) during the dry months. The collected water gradually seeps into the ground and increases the water level of nearby wells. In coastal areas, they also minimize the flow of fresh water into the sea.
It is a simple and cost-effective method used widely in rural areas. Series of stone bunds build one behind the other have proved to be more effective than modern concrete dams in some villages, as these local structures can be easily repaired by farmers themselves. Although they require many skilled laborers during construction, the cost is mostly shared by all the villagers as it is a common structure. However, with more people opting for personal borewells and handpumps, the water level in open wells has gone down severely, taking a toll on marginal villages. Thus, rejuvenating these community-based Kattas can go a long way in sustainable water management in India.
Sand Bores
Sand Bore - Traditional Water Conservation India
Sand bores provide a safe alternative for farm irrigation without affecting groundwater. This technique uses the concept of extracting water retained by sand particles. Sand particles act as great water filters by retaining the salt content at the bottom and gushing pure water out. White sand is believed to yield water clean enough for drinking too. Sand deposits (as high as 15-30 feet) left along banks of rivers is dug using a manual soil cutter. Casing PVC pipes is inserted to act as filters and an electric or diesel motor is used to pump sweet water out.
The entire set-up costs around INR5,000-7,000 and requires less maintenance when sand deposits are fine and clean. The sand bore technique has been used in Karnataka since decades. The only drawback is that it can only be practiced in coastal areas or in areas with high sand deposits. The adjoining picture shows farmers preparing the PVC pipe filter with holes.
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