You might wonder why we still use an age-old tradition of collecting rainwater. That is because of the numerous benefits it continues to offer even in contemporary times. Rainwater is one of the purest forms of water available on our planet. Rainwater harvesting is accepted as the long-term solution to the water crisis in rural and urban areas worldwide. In fact, the demand for the rainwater harvesting system has increased due to the shrinking groundwater level and erratic water supply from the municipalities. The system entails gathering and storing rainwater from surfaces where it falls so that it can be used later. Generally, the intended use of rainwater harvesting includes watering the garden, filling up the pool, washing cars, etc. The essential components of this system involve catchment, conveyance, and storage.
Steps for building a rainwater harvesting system:
Step 1 – Determine the rainwater harvesting potential of your house
The potential for rainwater collecting is the amount of precipitation that could be captured in a particular location. It is calculated by multiplying your available surface area for collecting rainwater by the amount of rainfall that falls each year. The catchment of a rainwater collecting system is the area that directly absorbs rainfall. It could be an open area that is paved or unpaved, a terrace, or a courtyard. Therefore, the catchment is the region that supplies rainwater to the harvesting system.
Step 2 – Determining the layout.
The tank's layout and the placement of its pipelines are planned to maximise the usage of its collection surfaces. You can use a spread-out or clustered tank to do this.
Step 3 – Setting up the storage
The rainwater collection from the roof of the house is directed to a storage tank. This storage tank has to be designed keeping in mind the water requirements, rainfall, and availability of the catchment. The collecting system should have the following-
A first flush (sometimes referred to as a roof washer) device that will direct the first flow of water away from the tank and a mesh filter at the mouth.
A filtering system
An air gap to avert stormwater backflow
Excess water overflow system
Storage determination generally depends on the location and the intended usage of the rainwater
Step 4 – Finalise the features in the system
First flush diverters - The first flush is used to evacuate the water from the initial shower. To prevent the potential contaminants from the atmosphere and the catchment roof from contaminating the storable/rechargeable water, the first rain shower must be rinsed off. It will also assist in clearing away the silt and other debris that dry seasons leave on the roof. At the end of each drainpipe, initial rain separators should be installed.
Filter - To effectively remove turbidity, colour, and microbes from water, filters are essential. Water should pass through filters after the initial downpour. On top of the storage tank, filters made of gravel and sand are constructed and installed. It keeps organic debris like leaves, silt, dust, and other particles out of the storage tank. Daily cleaning of the filters is needed following each rainfall. Clogged filters may overflow because rainwater cannot quickly enter the storage tank.
Limit sources of contamination - Ensure that your roof's surface materials are suitable for capturing water of the right quality and trimming any overhanging vegetation. Install gutter mesh to stop debris like leaves from clogging gutters and pipes.
Additional features – You can consider other features like a UV filter, gravity feed, groundwater aquifers, automated irrigation system, etc.
Step 5 – Installing the pipes and tank
Pipes - To install the pipes, you will have to have the necessary permissions from the authorities. You can begin digging the trenches if they are laid underground, or you can connect using connectors. To prevent sediment from accumulating in areas that are difficult to clean, it is best to have the pipe as a single fall. It is advisable to get enough head between the collector location and the tank to handle sudden, heavy downpours.
Tank - Follow the below steps to install a tank –
Create a tank stand that fits the area.
When the tanks are empty, place them on the stand and watch that they don't blow away.
Connect them so that they operate as a single volume. Put a valve on each tank, primarily for maintenance purposes.
To prevent the most contaminated rainwater from entering your rainwater tank, use first flush diverters.
Connect a drainage system of some kind. If the tanks are in a sump, there must be plenty of drainages and an overflow system. Pumps will flood if the overflow is undersized.
Finalise the connections between the tanks and PVC collector pipes.
Install a tank gauge to routinely keep an eye on your water level and usage.
Water conservation unquestionably impacts a sustainable environment as the need to combat climate change becomes more urgent. Groundwater is the principal source of freshwater for the nation's expanding household, agricultural, and industrial sectors. It has been noted over time that the requirement to utilise groundwater resources for varied daily purposes, such as urination, bathing, cleaning, agriculture, drinking water, industry, and ever-changing lifestyle, is resulting in significant water waste. Although numerous technical solutions are being created to reduce water waste, the impact will be more significant if each individual helps conserve water by reducing or optimising the groundwater for daily activities. One simplest and most effective ways to conserve water is to implement rainwater collection and groundwater recharge. This procedure can be effectively used in place of the traditional water sources currently in danger of running dry.
