New Construction – Make it water sustainable

New Construction - Make it water sustainable

Contributor,
Ganesh Shanbhag
Software Engineer by Profession, EcoFriend by passion!!

Bengaluru is an under construction city. Billions of Sq ft of new construction has been happening year after year since the IT industry boom of the late 90s and early part of this millennium. May it be residential homes, apartments or the commercial spaces, the first thing done on the land, even before tilling is, digging of multiple borewells. Very conservative estimates say, Bengaluru has over 10 lakh borewells extracting the ground water. And for builders who pour concrete into every square inch of the land, water is very precious during construction. Concrete results in 8% of Global Carbon emissions and is a material with a large quantity of embodied water. Embodied water is the water used in making up Concrete from Raw materials, Curing etc till it gets its final shape. And unfortunately, over 90% of ground water is consumed even before somebody starts staying in those buildings. This is the impact of embodied water in the concrete. Having said all these, if you are planning a new construction, you can follow these steps. 1. Construct with Stabilized Mud Blocks or Rammed earth instead of Concrete. This technique sources all locally available raw materials and has very less embodied water and embodied energy.

Do not drill borewells, instead plan for an open well. Open well draws water from shallow aquifers and is easy to recharge. Also, the water from the open well is really soft and needs no further treatment.
Filter rainwater falling on roof top and use it for all potable applications.
Overflowing filtered rainwater and surface runoff should be directed towards replenishing wells.
Have dual plumbing setup for both inlet and outlet. Meaning, have a separate provision for flush water and separate outlet pipes for Black & Grey sewage.
Treat sewages for reuse and ground recharging. There are a lot of natural methods available to treat the sewage further to make it ready for reuse. Use treated water for flushing, landscaping and even ground water recharging.
Have flow limiting aerators installed for all plumbing outlets like tap, shower head etc.
Set the flush tank to minimum capacity to limit flushing of water.
Plan for setting up water meters for units with multiple dwellings (Like Apartments). The commodity which can be measured can be metered and this will bring down rampant misuse of water.
Have automatic level controllers installed for all kinds of pumping.