Rainwater Harvesting | Introduction, Importance, Methods of Rainwater Harvesting

Rainwater harvesting is an easy technique or technology that collects, stores, transports, and purifies rainwater that flows off rooftops, parks, roadways, and open spaces for later use.



Introduction of Rainwater Harvesting


Rain water harvesting is the gathering and storing of rain water that falls from roofs, parks, roadways, and open spaces, among other places. This rain water can be stored into the groundwater.

This usually includes collecting rainwater from a roof. Rainwater will gather in gutters, which will then direct the water through downspouts and eventually into a storage container. Rainwater collection systems can range from the basic to the complex, capturing rainwater into massive water tanks to meet your complete household’s needs.

The rainwater harvesting system is one of the most effective and widely used ways for water conservation. Nowadays, a serious reason to worry is the lack of good quality water. However, rainwater that is pure and of excellent quality may be utilised for other cattle needs as well as irrigation, cleaning, bathing, and cooking.


Importance of Rainwater Harvesting


  • The problem of the water crisis in many regions of the world may be permanently solved through rainwater harvesting.
  • Despite the fact that the planet is made up of around three-fourths water, only a small portion of it is used for farming or human use and it can be solved through rainwater harvesting.
  • Farmers that depend on the monsoon for source of water will find this to be the perfect option.
  • Lack of clean water forces people to drink contaminated water, which leads to a high percentage of death rates and water-borne illnesses.
  • It could be a backup plan for the primary water supply, particularly during dry seasons.
  • Rainwater collection is important because it may be saved for later use.
  • In areas with irregular rainfall throughout the year, rainwater collecting is the appropriate solution.


Methods of Rainwater Harvesting


  • Surface Runoff Water Harvesting

Surface runoff water harvesting is a common practised in urban areas.

It is the process of gathering, conserving, treating, and storing runoff water for both present and future usage.   

Rainwater runs away as surface runoff in this approach and can be stored for later use. Additionally, the technique may make use of rainwater from other water sources, man-made surfaces, such as roads, parks, and gardens.

This approach may effectively gather a lot of water if the right technique is applied. However, as the runoff water could have certain contaminants, a proper treatment procedure must also be implemented.


  • Water may be collected using this technique for irrigation and agricultural usage.
  • The water that is gathered may be effectively used to create other goods and support a living.
  • This technique for collecting rainwater is ecologically friendly.
  • It stops freshwater from evaporating into the ocean and the seas.


  • Rooftop Rainwater Harvesting

It is a technique for gathering rainwater at its source. Rooftop harvesting involves collecting rainwater from a home or other structure’s roof by using the roof as a catchment.

Either it may be routed to an artificial recharge system or it can be kept in a tank. If used properly, this strategy, which is less costly and extremely beneficial, contributes to raising the local groundwater level.

Components of the Rooftop Rainwater Harvesting


  • Rooftop(catchment)

In rainwater harvesting, the rooftop acts as the catchment.

The catchment, or surface where the rainwater falls directly, is the part of the rainwater harvesting system that immediately absorbs the rainfall.

A building’s terrace or rooftop may serve as such a catchment.

In short, the catchment acts as the system’s source of water.


  • Pipes (Conveyance)

The pipes are yet another crucial element of the rainwater collection system.

Since they are used to transport rainwater gathered from the catchment to storage reservoirs and tanks, the pipes are also referred to as the conveyance.


  • First Flush

In most cases, the rainwater that is originally collected may include some contaminants. In order to stop the water held in the reservoirs from being contaminated (such by acid rain), the initial accumulation of rainwater is flushed out.

The first flush is the name of the tool used for this purpose.


  • Filters

Filters are components of a rainwater collecting system that are used to filter stored rainwater.

Rainwater is filtered to get rid of any unwanted pollutants, germs, turbidity, and other things that could be in the water.


  • Storage Unit

The collected water is kept in the storage container.

Depending on the size of the harvesting system, a variety of storage containers can be utilized.


Rainwater Harvesting Projects


  • Rainwater Harvesting Project at the Maharashtra Police Academy, Nashik
  • Rainwater Harvesting Project at the Maharashtra Police Academy, Naigaon
  • Rainwater Harvesting Project at Malcolm Baug in Mumbai
  • Rainwater Harvesting Project in Dahanu Taluka
  • River Rejuvenation Project
  • Rainwater Harvesting at The Directorate of Police Wireless Headquarters, Pune