Bengaluru, the IT capital of the country is today facing an unprecedented “water crisis”. The situation is indicative of water supply parameters that are ‘extremely stressed’ with the rapid decline of the groundwater table, especially in the peripheral areas of the city. These regions are now almost wholly dependent on tankers for their potable and drinking water supply.Rapid urbanization has led to escalating demand which compels the borewell suppliers to dig deeper at increasing depths in their search to find water. Although burgeoning concretization and poor quality of the water bodies present are crucial to the current predicament, mismanagement of the available resources is a prime contributor to the existing crisis. A survey conducted by the Bengaluru Water Supply and Sewerage Board reveals that 23 TMC of rainwater is wasted every year due to the lack of rainwater harvesting structures.
The Process & Techniques
Pre and post implementation
The site was an undulating sloping terrain with hard soil. Thus, the percentage of percolation was minimal with major water getting wasted as surface run-off to the naala.With a consistent approach to save and conserve water in the highest capacity, the sizing of the tanks and fixtures were consciously considered with respect to the users and their usage. Meticulous planning in having large open spaces housing native plant species helps in direct percolation as it loosens the soil and enables further filtration.
Rainwater harvesting structures
Apart from percolation pits created to capture surface run-off water, one of the unique rainwater system’s implemented in the project tackles two major goals concurrently: 1) maximizing the capture of roof rainwater and 2) groundwater augmentation through artificial recharge. This is done by channelizing all the pipes that capture the rainwater from the roofs to assimilate into small circular water tanks called ‘buffer’ tanks distributed around the community. These buffer tanks have earth as the base and are interlinked with recharge borewells.
Effective reuse of domestic water
Housing five hundred families, the wastewater generated per day on an average is 3 lakh litres. By using an economical, environment-friendly and a decentralised wastewater system to treat the sewage collected in the communities, we are able to recycle and reuse 2.4 lakh litres. The treated effluent conforms to the to the KPSCB norms and is reused for secondary use like toilet flushing and irrigation of landscape in the property.
Scope of replication
The implemented methods are easily replicable ideas as they are not intricate or complex. In today’s scheme of things, the domino effect needs to be set in motion with these practices to bring about a positive impact to the society and environment. The decentralized wastewater system is much more economical in comparison to the conventional STPs and far more effective. By harvesting water and treating the wastewater generated at source economically for reuse, we can insure against possible water shortage in the future.
Management at GoodEarth Malhar
By implementing an efficient rainwater system for water conservation and groundwater recharge along with an effective decentralised approach for wastewater management, our project, ‘GoodEarth Malhar’, an eco-village in Bengaluru, is an exemplary model that showcases efficiency of water use.The comprehensive approach such as creating large open spaces, run-off percolation pits, buffer tanks, landscaping with indigenous species, grey water recycling and low-flow fixtures have collectively enabled the community to successfully stay off-the-grid throughout the year.