The city sprawls on all sides, particularly on the roads that lead out of it. The era of urbanisation is well and truly upon us but it is also an era of real estate boom or bubble as you prefer. This large development with its attractive gate and billboard advertises itself as a new haven. It has plotted development, apartment blocks, a school and even a hospital. Tree-lined avenues and turf grass welcome potential buyers and clients to a visually compelling office nicely air-conditioned and with helpful staff explaining the details patiently.
A stone’s throw away is the site office. Slightly grubby with materials lying around and harassed looking, hard working engineers and staff busily at work. The manager has a worried countenance as have the designers.
The only source of water for this large 60 hectares of development is groundwater and it is running out. Borewells are frequently going dry and have now reached depths of 300 metres and more.
A couple of them only yield and they too are sputtering. The entire campus is dependent on tankers which too source their waters from nearby bore-wells. How long before they too hit rock bottom ?
The periphery is where the city lines do not reach and this is where the new economic growth is playing itself out as villas, condominiums and plots. Golf courses make their appearance and yet the thin line that keeps them alive is groundwater and that is the crisis.
Solutions What are the solutions which could be sustainable? How should such large developments manage water? Here are some directions that can be followed.
Firstly since groundwater is likely to be the only source of fresh water do a good hydro-geological survey and understand the potential availability of groundwater. This survey is not merely to identify points for drilling bore-wells but to provide an idea of the soil profile, the storativity potential, the transmissivity, recharge zones and discharge zones amongst others.
Secondly locate the development in a watershed. Identify the lowest point in the watershed. If it is a tank or a lake make sure that is protected and rejuvenated by the concerned authorities. All channels leading to the lake should be conserved and it should made sure that surface runoff reaches a de-silted lake and therefore recharges the groundwater.
Every flat and every plot should have water meters and this water should be priced to discourage unlimited demand and to manage it within sustainable limits. Anything more than 100 litres per person per day should be treated as a luxury.
Set up dual and triple plumbing lines for each flat and each building. The highest quality water in the kitchen and in the sink for brushing. A second quality water where there is contact with the skin and a third quality for flushing and gardening.
Set up a landscape and a garden system which is completely tree based and has no hint of water-guzzling grass. Even waste-water should be used minimally for the landscape area.
Harvest and store in the aquifers every drop of rainwater that falls on the layout. Creating ponds may be self-defeating as there are huge water losses due to evaporation. The best place for stored rainwater is in sump tanks or in the aquifers. Design the rainwater harvesting system well for such a purpose.
Source tertiary treated waste-water from the city and set up your treatment plant to further purify it even for potable purpose. Wastewater generated from within the development should also be treated to potable standards whether for direct consumption or through a system of wetlands and then indirect after treatment for potable use.
Large scale developments can use water in several million litres per day scale. To prepare and design at the beginning is to be water-wise.
