By Chandeep Arora:
S Ganesh Mallya, a high school teacher cum Sunday farmer in Yedapadavu in Karnataka, has green his plot without bore wells. Using simple techniques to catch rainwater, he has managed to raise the water level in his open well and grow a bountiful farm. In another story, Aakash Ganga (AG) which is a rainwater harvesting system is currently installed in six drought-prone villages in Rajasthan, the driest state in India. The AG system rents rooftops from homeowners and channels the rooftop rainwater through gutters and pipes to a network of underground storage reservoirs. This network of reservoirs is designed to provide 10 — 12 liters of water daily to every person in an entire village for a year; to-date, it has helped 10,000 villagers gain access to clean water.
Rain water is the purest form of raw water available on earth. Rain water harvesting is the process of collection of rain water from rain receiving surfaces like building roof tops, courtyards, hill slopes, or specially made mini-catchment surfaces. The water is collected in storage tanks installed above ground, partly above and partly underground, or fully underground depending on the local situation. Since the water is collected before it comes in contact with any contaminated surface, it remains free from physical, chemical and fecal contamination. For removing suspended impurities, if any, the water is collected in reservoirs. It provides for an alternative with the world facing an acute shortage of water resources. A number of reasons contribute to the dearth of water. The high rate of population growth and high level of urbanization has resulted in over-development of ground water resources. Thus the ground water levels are declining at an alarming rate of 0.20 m per annum. In order to increase the natural ground water resource rain water harvesting has become increasingly important in ground water management. In the groundwater recharge the runoff on the ground is collected and allowed to be absorbed, adding to the groundwater. Considering the usage in urban areas, rain water can be used as an independent source of water supply during water restrictions that is somewhat dependent on end use and maintenance. It can be adopted in cities for continuous water supply, increasing the soil moisture level for utmost greenery and to improve the quality of groundwater. In the household level it can used in various day to day activities. Though for drinking purposes it may require thorough cleaning.
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. The rural areas where water supply is a crisis, rain water harvesting comes as a boon. In the recent years there has been an increase in the number of suicides attempted by the farmers due to lack of water for their farms. Irrigation facilities are not adequate in many remote villages. In such cases, proper use of rain water can provide the farmers a substitute for irrigation facilities. In such story, the farmers of Ambaredi village, Rajkot District, boast of their lush green fields and full brim river even during the dry months of the year. Open dug wells are the main source of water.
With the population growing at an alarming rate and limited availability of groundwater and surface water, this precious natural resource needs to be recycled and be of proper use. Rain water harvesting is the need of the hour. It is one of the simplest and cheapest ways of keeping a check on the depletion of one of the most valuable natural resource. In the words of Ms Sheila Dixit, “Unless we get rainwater harvesting as a movement we do not have a bright future and for that people have to be motivated to make this a habit. It is not something that we should do to ensure a better tomorrow for our future generation, but it is something we need to do to save the planet and the human race.”
With inputs from: www.indiatogether.org/environment/water.htm