Sunday, October 18, 2015

City Level Rain Water Harvesting and Water Recycling: Workshop

We often talk of taking steps to harvest rainwater (by tapping rainwater on roofs o store at ground level plastic tanks and pumping up back to roof)  or recycling grey water (using double plumbing to recycle toilet water to flush further  for flushing, washing or gardening) at the house scale.

For a planned town like New Town, it may be possible to scale up both activities to the city level.

The entire New Town has a network of box drains for draining off rain water from roads. These converge ultimately to a canal (like the link canal or pass-khal in Action Area 1, for example) and a Drainage Pumping Station (DPS) pumps out the water to the Bagjola Canal of Irrigation Department that ultimately takes it to the sea. The possibility I'm asking my engineers and planners to explore is as follows: can the DPS send the water to the nearby Tarulia raw water reservoirs where water from the 6ft pipes from Hoogly river will be brought in? In that case, we will save ourselves the cost and energy needed to pump in water from a 11 km distant source. We will also be able to supply additional water into the distribution channels.

For waste water too, there are Sewage Treatment Pumps (STPs) all over various locations of New Town. After treatment, the waste water is pumped out to bheries or canals. There is the possibility of using the treated water, with a second stage purification, to use for gardening (think of water needs of plants of Eco Park/ tea garden/ chilren's parks, greenery on medians) or in community toilets (think of Pay & Use toilets at Eco Park / Rabindra Tirtha/ Convention Centre etc) for flushing and washing.

I have advised Mr Debashis Banerjee, EE PHED to make out a basic concept note / discussion paper within the month. Thereafter we can have a technical discussion involving engineers, planners and experts.

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Khabar 365 dt 18 Oct 2015

Anandabazar dt 18 Oct 2015

Abz dt 18 Oct 2015
Bartaman dt 18 Oct 2015
Asian Age dt 18 Oct 2015


  1. While rIn water harvesting practice to city level scale is indeed a great thought... I have my apprehension on sewage being treated... The sewage is rich in organic materials and it flowing into the bheris is actually that keeps the wetalnds teeming with life, while the waste get organically treated. My suggestion is to ensure a good amount of that waste is received byvtge wetlands untreated so that it keeps ecological balance and the uniqueness the wetlands has....That is why it is in the Ramsar the first place... It already is a green and sustainable and low energy city level natural STP... All it needs is that only an optimum amount is released into it and... The rest of the excess population's waste can be done as you suggested.

  2. Dear sir,
    I think that idea is worth implementing after ensuring about the quality of recycled water.

    Regarding e-bus :( just a suggestion)
    I feel that the minimum distance on a single run can be increased further as in Us the buses which can cover 400 kms on a single run have been tested successfully. Also buses can have solar panels installed to additionally run the electronic gadgets and devices installed within the bus if possible.