Bengaluru – Once known as a city with over thousand lakes, is today left with less than hundreds and less than ten in drinkable condition. Along with destruction of lakes, we also destroyed the fragile ecosystem associated with it, the wetlands. Wetlands were nature’s sponge mechanism to recharge ground water, keep surrounding flora & fauna in healthy state. It was the exchange pool for macro and micronutrients. However, we have lost them all. Wetlands are also ecosystems natural sewage treating mechanisms. Much before the advent of power guzzling large Sewage treatment plants, wetlands played a very important role in breaking down sewage and other organic matter and reclaiming water. With the concretization of the city, there is even more stress on wetland ecosystems.

However, metropolitan cities like Bengaluru can as well try to mimic the natural wetlands by constructing the wetlands. Constructed wetlands (CW) systems are fully human-made wetlands for wastewater treatment, which apply various technological designs, using natural wetland processes, associated with wetland hydrology, soils, microbes and plants. Thus, CWs are engineered systems that have been designed and constructed to utilise the natural processes involving wetland vegetation, soils, and their associated microbial assemblages to assist in treating wastewater. Synonymous terms to “constructed” include “man-made”, “engineered” or “artificial”. In general terms, the landscaping we do in front of every house, apartment complex can act as a CW.

CWs can be designed based on parameters of input water, type of vegetation needed, type of fauna needed in the water and the desired quality of output water. There are large choices of vegetation suited for any kinds of landscape requirements. The CW will act as a mini ecosystem, soaking in enough water for the aquifer recharge and also water immediately available for reuse.

There are real good examples of constructed wetlands available in Bengaluru today. A Bengaluru based start up on Sewage Treatment; EcoSTP has pioneered in Plant Based Filter which uses wetlands hydrology for sewage treatment. Indian Railways owned Rail & Wheel Factory has built multiple wetlands in the campus which recharges all the wells. This design & implementation of Wetlands was done by Shri Ajay Singh, who is also known as Rail Water Man.

In general, cities like Bengaluru can have millions of smaller and micro constructed wetlands which will negate the impacts caused by destruction of macro wetlands & make it water abundant.