Here is a guide on how to plan and install a rainwater harvesting system in Pune
The steps involve collecting the rainwater in an area, filtering it and channelling it into a collection pit for storage. Further, maintenance also plays a huge role in effective rainwater harvesting.pune Updated: Jul 09, 2017 17:57 IST
- Identification of catchment area to collect water. Can be terrace areas, car parking, roads or even concrete surfaces.
- Installation of filters
- Installation of dummy bore-well or recharge shaft, for filtration (water percolates from here to the main bore-well)
- Determination of the Collection point or the Storage unit ( bore-wells or water tanks)
- Identification and installation of a water retrieval system to draw water from the storage units ( Pumps)
- Maintenance: Cleaning of catchment area, installation of filters, etc.
In the lieu of the benefits of rainwater harvesting, experts shared the basic outline of the installation process of rainwater harvesting projects in the city.
To begin with, rainwater harvesting essentially involves collecting the rainwater in an area, filtering it and channelling it into a collection pit for storage, so that the water is not run off and wasted. According to S V Deshpande, former joint director (engineering) of Groundwater Surveys and Development Agency (GSDA), “It is the recognition of a suitable catchment area to collect water. These catchment areas can include terrace areas, car parking, roads or even concrete surfaces.”
The area needs to be equipped with a ready channel for the water to flow into the pipes easily. For the process, one can also consult an expert.
“Firstly, the consultancy provides a questionnaire which the interested individuals will have to fill. This would be about the details of their building or society. Then they survey the society or buildings to understand the scale and logistics for setting up the rainwater harvesting system. From the number of borewells, to the roof space, to even the condition of pipes and pumps, everything is checked in the process. Following this, a design for the project is penned down, and explained to the people. A report and presentation is also prepared and presented to them, outlining the kind of expenditure required, the kind of affordable system to be installed and the sustainable options with respect to situations necessary for the project etc.,” explained Jyoti Panse, an award-winning architect and water management expert.
“Once the catchment area is decided, installation of filters and determination of the collection point or the storage unit is the next step,” said Sanjay Kangralkar,a consultancy official from Era Hydrobiotech Energy Pvt. Ltd.
“One needs to find out the existing borewells in the society or building area, or the possibility of digging one, or installing a water tank for the collection of the rainwater. Further, the channel of the water flow needs to be checked and it should be ensured that the water can easily flow from the catchment area through the pipes into the collection pit. Sometimes, it is best to let the water flow into a live borewell as it increases the groundwater table,” he added.
The third step is to develop a water retrieval system through which the water can be drawn from the storage units whenever required. “Usually, we use pumps to retrieve water from borewells. If the area has a low groundwater table, it requires more electricity to draw water from the wells. In that case, with rainwater harvesting, the groundwater level comes up and is therefore much more easier to draw water,” said Anand Ambekar, a rainwater harvesting consultant.
“The final and the most important step is to maintain the system. It starts with keeping a check on the filters installed. Especially prior to the monsoons, the rooftops need to be cleaned, along with the filters, for the unobstructed passage of water through the pipes,” he added. As the water is usually collected from rooftops or ground surfaces, filters become an important aspect of the system. Experts emphasise on the necessity to routinely clean the filters.
“For better filtration, the water is allowed to flow through a filter into a recharge shaft or a better version of the dummy borewell. This water then percolates into a live borewell,thus adding another level of filtration,” Deshpande, added.