Rainwater Harvesting: How it works? What to do?

Catching water where and when it falls - Every raindrop matters now as the whole world stares helplessly at an unprecedented kind of water shortage.
Collecting and storing rainwater for reuse rather than draining it may be the only way out of prolonged periods of drought. Why?

Whatever your government can do, it cannot produce water.

The idea behind the process is simple and ancient. Rainwater is collected when it falls to the earth, stored and used at a later date. A few basic elements are usually required for all RWH RainWater Harvesting systems.

• 1. Catchment area


• 2. Transport system


• 3. Filtration system


• 4. Storage area


• 5. Loading area

1. Catchment area

Here the rain falls. Clean catchment areas are necessary to maximize the harvest. Based on these criteria, the harvesting method differs.

Harvest on the roof

Today, roofs are the place for solar panels, wind generators and gardens. Harvesting water on the roof is therefore a comparatively simpler process. All you need is a clean terrace, a pipe to connect the roof and storage, and a filter to shield the dust particles.

Build an underground storage tank. If you want to recharge the aquifers, set up an unlined pit with layers of gravel and sand to filter out the mud.
Note: This pit should be at least 1.5 m deep so that it never overflows. This allows water to seep into the soil.

Setback harvest

The kickback area usually includes the driveway, balcony, yard, and front yard. Rainwater harvesting structures should not be built anywhere without considering the nature of the soil.

• In rocky terrain, water can be stored in catch basins, as new groundwater formation is not possible.


• In the Clayey area, a small hole can be dug in a recharge well if it gets no more sandy than 15 feet, and a 6 inch pipeline can be put in to bring the water to a deeper level.


• In sandy coastal areas, a well 3 to 5 feet in diameter would be sufficient in sandy regions. If the open areas are not paved, the surface runoff seeps away and the groundwater is recharged.

2. Piping system

Rainwater is transferred through the canals built around the edge of a sloping roof to direct the flow of water from the catchment area to the storage area. These gutters can be made of galvanized iron sheet, PVC material, bamboo or betel logs.

3. Filtration systems

Four types of filtration processes can be used in a RWH system:

Screening:

This first-level process filters out gross pollutants such as leaves, feces, and other materials.

First rinse:

A valve is placed on the second level to ensure the division of the first few minutes of rainwater, which collects dust and other contaminants.

Filtration:

Next-stage filters remove dissolved organic and inorganic particles in rainwater before they are collected. Such a filter shields all dust particles.

Settlement tanks:

Settlement basins remove silt and other coarse materials.

Note:

There are 2 options available for using the harvested rainwater:

• * Charging into the aquifer

4. Storage area

Rainwater from the roof is stored in catch basins (underground water storage tanks). Households with structures connected to sumps report that good recharge occurs with only 1/3 of the filled filter length. However, problems related to the cleaning of drip pans and their limited shelf life are the primary concern.

5. Loading area

Surface runoff water is mainly used to recharge the soil. Such recharge is accomplished either through percolation pits or recharge well processes.

Note:

• Identify the loading zones

• Ensure the quality of the rainwater

• Avoid groundwater pollution

Perforated slabs and alternating plaster sections allow increased infiltration. However, by using pebbles, the infiltration pits can easily become silted up. Cleaning may not be easy as it almost resembles a deep borehole.

In most cases, a refill hole with no filter media is the best option as the soil can facilitate natural filtration.

Benefits of using rainwater

Personal benefit

• 
  
  
  
  The rainwater that falls on your roof and property is essentially free.


• Water can be used for several non-drinking ...