What is Rain Water harvesting?
Rain Water Harvesting is an act of accumulating and storing rainwater for reuse. As we know rainwater is the purest form of water, we can utilize this water for various purposes after necessary purification process as per required. This system can be a boon in regions where there is shortage of water. This problem is common in today’s big cities. Hence rainwater harvesting can be very effective in these areas.
- Storing rainwater for ready use in containers above or below ground.
- Charged into the soil for withdrawal later (groundwater recharging).
- Provide drinking water
- Provide irrigation water
- Groundwater recharge
- Reduce storm water discharges, urban floods and overloading of sewage treatment plants
- Reduce seawater ingress in coastal areas.
From where to harvest rain?
- Rooftops: If buildings with impervious roofs are already in place, the catchment area is effectively available free of charge and they provide a supply at the point of consumption.
- Paved and unpaved areas i.e., landscapes, open fields, parks, storm water drains, roads and pavements and other open areas can be effectively used to harvest the runoff. The main advantage in using ground as collecting surface is that water can be collected from a larger area. This is particularly advantageous in areas of low rainfall.
- Water-bodies: The potential of lakes, tanks and ponds to store rainwater is immense. The harvested rainwater can not only be used to meet water requirements of the city, it also recharges groundwater aquifers.
- Storm-water drains: Most of the residential colonies have proper network of storm water drains. If maintained neatly, these offer a simple and cost effective means for harvesting rainwater.
Whether to store rainwater or use it for recharge?
The decision whether to store or recharge water depends on the rainfall pattern and the potential to do so, in a particular region. The sub-surface geology also plays an important role in making this decision.