Rainwater Harvesting is an intelligent idea and concept to collect the water during monsoon season so that the water scarcity of other seasons can be fulfilled. Rain water harvesting is that process in which rainwater is preserved in tanks or diverted underground so that it can be used in various applications.Such stored rainwater can be used for agriculture and irrigation. Such harvested rainwater can reduce the over dependence on municipal water supply saving money as well as time.
Process & Types of Rainwater Harvesting
Direct Pump - Submersible
The most common type of professional rainwater harvesting system, specifically for domestic premises, and is generally the easiest one to install. The pump is located within the underground tank and harvested water is simply pumped directly to other appliances. One precaution to be undertaken is when the tank tends to be in danger of running dry, in such case a small amount of mains water is fed to it in order to maintain supply. For bigger commercial projects, such systems tend to be with dual pump arrangements.
Suction pump differs from the submersible as in this system the pump is not placed inside the tank, but is located within a control unit within the house (e.g. utility room). The unit is also responsible for the backup from mains water supply, so that there is no need to send mains water down to the tank.
Indirect gravity system differs as the harvested water is first pumped to a higher-level tank (header tank), from where it is then allowed to supply the outlets by gravity alone. In this system, the pump only has to work when the header tank needs filling. Also, the mains water/direct water is fed directly to the header tank and not into the main harvesting tank.
The indirect pumped is similar to the indirect gravity system, except that the position of internal tank can be at any level in the premise, as it does not rely on gravity to supply the outlets. For supplying the outlets, a booster pump is used. The benefit of this system is that the mains back-up need not be fed to the underground tank. Also, there is a great flexibility as the booster pumps can be adjusted to suit the flow and pressure requirements of the premise.
Process of Rain Water Harvesting System
They are surface which receive the rainwater directly and provide them to the system
Coarse Mesh :
at the roof to prevent the passage of debris.
Channels all around the edge of a sloping roof to collect and transport rainwater to the storage tank. Gutters can be semi-circular or rectangular and could be made using locally available material such as plain galvanised iron sheet (20 to 22 gauge), folded to required shapes.
They are the pipelines or drains that carry rainwater from the catchment or rooftop area to the harvesting system.
Downspout Screen :
Protect the downspout from debris.
Tank Screens :
Your tank will need a screen as additional protection from leaves and other debris.
A first flush device is a valve that ensures that runoff from the first spell of rain is flushed out and does not enter the system. This needs to be done since the first spell of rain carries a relatively larger amount of pollutants from the air and catchment surface.
Filters remove contaminants before the water goes into the storage tank
Help push water out of the storage tank.