The Steps To An Efficient Rainwater Harvesting System

With the human population facing major water scarcity and reports suggesting that more than half the world’s population will be living in water-stressed regions by 2050 (Water Aid), there is an urgent need for a system that helps the human race get access to fresh water. The solution to this problem is rainwater harvesting. It is the most sustainable way of accessing fresh water and does not require any energy for functioning. It does not deplete any natural resources, on the contrary, helps conserve and protect the natural habitat. This read is all about understanding the steps of rainwater harvesting and understanding how there is a need for rainwater harvesting.

What is rainwater harvesting ?

The saline water from the sea gets evaporated due to the heat from the sun, forms clouds and falls as rain as freshwater. A significant part of this rainwater drains out into oceans and drains. If we are able to harness this effectively, it can be an important source which can be used for various applications. So, in short, rainwater harvesting is the process of storing rainwater for reusing rather than allowing it to run off. However, it is vital to understand the steps of rainwater harvesting before that.
 

Types of rainwater harvesting :

The types of rainwater harvesting will help us understand the system better. It is best to learn about them so we know which one works best for us and accordingly learn about the steps of rainwater harvesting.

Before we learn the steps of rainwater harvesting, let’s understand the advantages of rainwater harvesting.

Advantages of rainwater harvesting :

1.   Promotes adequacy of underground water: With the rise in population, the dependency on groundwater is increasing. Many residential colonies and industries are extracting groundwater to fulfill their daily demands. This has led to a depletion of groundwater which has gone to a significantly low level in some areas where there is huge water scarcity. Rainwater harvesting enables groundwater levels to be further sustained rather than depleted.

    

2. Mitigates the effect of drought: Many countries, especially those with arid environments, use rainwater harvesting as a cheap and reliable source of clean water. When drought occurs, rainwater harvested in past months can be used. In deserts, ridges of soil are constructed to trap and prevent rainwater from running hills and slopes and enhance irrigation. Even in periods of low rainfall, enough water is collected for crops to grow.

    

3. Improves groundwater table thereby saving energy to lift water: Rainwater harvesting systems recharge run-off surface water to the underground aquifer to increase the water level and its quality. This has resulted in creating a sustainable groundwater table even when there is less rainfall.

    

4. Storing water underground is good for the environment: Storing rainwater underground eliminates evaporation and provides long-term storage, it can also replenish groundwater supply, prevent seawater from intruding, and protect ecosystems that depend on groundwater for their very survival.

    

5. It is cost-effective: Rainwater harvesting is a cost-effective alternative to other water recycling methods and is easier on the pockets as it is a long-term investment. Moreover, it removes the need for the transportation of water to the doorstep via various means.

    

6. It helps conserve water: The idea of harvesting water allows you to save water and use it effectively. This is the most effective way of water conservation. However, pay extra attention to the rainwater harvesting system in place. Carry out a strength test of the concrete, curing of concrete and the careful transporting and placing of concrete.

Steps of rainwater harvesting :

The steps of rainwater harvesting may seem lengthy however if implemented correctly, this system will last you for a lifetime.

• 1. Determine your catchment area and clean that area :

  The surface that receives the rainfall directly is known as your catchment area. It could be your terrace, courtyard, or paved or unpaved ground. Therefore, the catchment is the area, that provides water to the harvesting system. It is important to determine which area in your premises is best suited for this purpose and to clean this area just so there is no contamination at this stage.
  

• 2. Determine the layout :

  The layout and location of the tank and pipelines are determined in such ways as to maximize the use of collection surfaces. There are several options but the major ones are the spread-out tank option and cluster tank option.

• 3. Set up storage :
  

1. The rainwater collected from the roof of the building is diverted to a storage tank. The storage tank has to be designed according to water requirements, rainfall and catchment availability. Each drain pipe and collecting system must include :

• A mesh filter at the mouth and first flush (also known as roof washer) device which will divert the first flow of water away from the tank.

   

• A filtration system before connecting to the storage tank.

   

• An air gap to prevent stormwater backflow.

   

• Each tank should have an excess water overflow system.

   

• Excess water could be diverted to the recharge system.

   

  4. Install the pipes and tanks :

   

  For installing pipes :

   

• Seek the necessary permissions (if required) from the authorities to lay the pipes.

   

• Dig trenches, if laid underground.

   

• It is preferable to have the pipe as a single fall to avoid sediment collecting in places that cannot be reached easily for cleaning.

   

• Lay the pipes in trenches or otherwise and connect using connectors.

   

For installing tanks :

• Make a tank stand suitable for the property.

   

• Place the tanks on a stand and ensure they don’t blow away when empty.

   

• Connect them up so they can behave as one volume. Recommend putting a valve for each tank mostly for maintenance.

   

• Install first flush diverters to keep the most contaminated rainwater out of your rainwater tank.

   

• Connect some sort of overflow arrangement. If the tanks are in a sump it would require overflow arrangement and lots of drainages. When the overflow is undersized, pumps will flood.

   

• Make the final connection between the PVC collector pipes and the tanks.

   

• Install a tank gauge to regularly monitor your water level and usage.