Water is the key to life. Of all the planets known to man – Earth deserves to be called as the Water Planet. Rain being main source of fresh water its importance in conservation was not understood till now In scientific terms, water harvesting refers to collection and storage of rainwater and also other activities aimed at harvesting surface and groundwater. In general, water harvesting is the activity of direct collection of rainwater. The rainwater collected can be stored for direct use or can be recharged into the groundwater. Rain is the direct form of water that we know in the hydrological cycle, hence is a primary source of water to us. Rivers, lakes and groundwater are all secondary sources of water. In present times, we depend entirely on such secondary sources of water. In the process, it is forgotten that rain is the ultimate source that feeds all these secondary sources and remain ignorant of its value. Water harvesting means to understand the value of rain, and to make optimum use of rainwater at the place where it falls. HOW MUCH WATER CAN BE HARVESTED? The total amount of water that is received in the form of rainfall over an area is called the rainwater endowment of that area. Out of this, the amount that can be effectively harvested is called the water harvesting potential. Water harvesting potential= rainfall(mm) x collection efficiency Rainwater can be harvested for tow purposes: Stored for ready use in tanks above ground or below ground. Charged into soil for withdrawal later (groundwater recharging) Like your borewells, ringwells, etc. Different Types of Rainwater Harvesting Rainwater harvesting is the accumulation and deposition of rainwater for reuse before it reaches the aquifer. Uses include water for garden, water for livestock, water for irrigation, and indoor heating for houses etc.. In many places the water collected is just redirected to a deep pit with percolation. The harvested water can be used as drinking water as well as for storage and other purpose like irrigation. Water Harvesting And Artificial Recharge To arrest groundwater decline To improve groundwater levels and availability. To beneficiate water quality in aquifers. To arrest seawater ingress. To conserve surface water run‐off during monsoon. To enhance availability of groundwater as the specific place and time. To reduce power consumption. Need For Rooftop Rainwater Harvesting To meet the ever increasing demand for water. To reduce the run-off this chokes storm drains. To avoid flooding of roads. To augment the groundwater storage and decline of water levels. To reduce groundwater pollution. To improve the quality of ground water. To reduce the soil erosion. Rainwater Harvesting - Advantages Provides self-sufficiency to your water supply. Reduce the cost of pumping of ground water. Provides high quality water, soft and low and low in minerals. Improves quality of ground water. Reduces soil erosion in urban areas. The rooftop rainwater harvesting is less expensive. RWH systems are simple that can be adopted by individuals. Rooftop RWH systems are easy to construct, operate and maintain. In hilly terrains, rainwater harvesting is preferred. In saline or coastal areas, rainwater provides good quality water andWhen recharged to groundwater it reduces salinity and also helps in Maintaining balance between the fresh-saline water interfaces.
