Rainwater Harvesting

Rainwater harvesting is the simple process or technology used to conserve rainwater by collecting, storing, conveying and purifying of rainwater that runs off from rooftops, parks, roads, open grounds, etc. for later use. Here, let us have a look at the diagram of rainwater harvesting system.

Rainwater harvesting systems consists of the following components:

• Catchment- Used to collect and store the captured rainwater.
• Conveyance system – It is used to transport the harvested water from the catchment to the recharge zone.
• Flush- It is used to flush out the first spell of rain.
• Filter – Used for filtering the collected rainwater and removing pollutants.
• Tanks and the recharge structures: Used to store the filtered water which is ready to use.

The process of rainwater harvesting involves the collection and the storage of rainwater with the help of artificially designed systems that run off naturally or man-made catchment areas like- the rooftop, compounds, rock surface, hill slopes, artificially repaired impervious or semi-pervious land surface.

Several factors play a vital role in the amount of water harvested. Some of these factors are:

• The quantum of runoff
• Features of the catchments
• Impact on the environment
• Availability of the technology
• The capacity of the storage tanks
• Types of the roof, its slope and its materials
• The frequency,  quantity  and the quality of the rainfall
•  The speed and ease with which the rainwater penetrates through the subsoil to recharge the groundwater.

The rainwater harvesting system is one of the best methods practised and followed to support the conservation of water. Today, scarcity of good quality water has become a significant cause of concern. However, rainwater, which is pure and of good quality, can be used for irrigation, washing, cleaning, bathing, cooking and also for other livestock requirements.

The benefits of the rainwater harvesting system are listed below.

• Less cost.
• Helps in reducing the water bill.
• Decreases the demand for water.
• Reduces the need for imported water.
• Promotes both water and energy conservation.
• Improves the quality and quantity of groundwater.
• Does not require a filtration system for landscape irrigation.
• This technology is relatively simple, easy to install and operate.
• It reduces soil erosion, stormwater runoff, flooding, and pollution of surface water with fertilizers, pesticides, metals and other sediments.
• It is an excellent source of water for landscape irrigation with no chemicals, dissolved salts and free from all minerals.

Also Read: Disappearing Act of Water

In addition to the great advantages, the rainwater harvesting system has a few disadvantages like unpredictable rainfall, unavailability of the proper storage system, etc.

Listed below are a few more disadvantages of the rainwater harvesting process.

• Regular maintenance is required.
• Requires some technical skills for installation.
• Limited and no rainfall can limit the supply of rainwater.
• If not installed correctly, it may attract mosquitoes and other waterborne diseases.
• One of the significant drawbacks of the rainwater harvesting system is storage limits.

Know more about Rainwater Harvesting and other Biology related diagram concepts at BYJU’S Biology