'A million litres a day' solution to Bengaluru’s water crisis

Receding groundwater levels, depleting reservoirs, a rainfall deficit, dried-up borewells, water supply cuts, and long queues of women clutching their empty buckets—Bengaluru is no doubt facing one of the worst water crises in its history. The city presently has access to about 1,850 million litres per day (MLD) and needs at least 1,680 MLD more to meet its water needs.

While a multi-pronged approach involving solutions with varying timelines and costs is definitely underway by the state, an opportunity to make available an additional 100 MLD (million litres per day) at zero capital cost is being missed and should be tapped immediately. This is done through the use of tap aerators. For the uninitiated, the aerator is a small attachment that can be inserted at the tip of most taps.

The humble tap aerator, no bigger than a thumbnail, reduces the flow of water from 12–18 LPM to 3-6 LPM in hand wash and kitchen taps, enabling the saving of more than 50 per cent of water without affecting functionality. They are a practical solution to conserve water in urban areas.

The proof of pudding can be seen in a 120-flat apartment complex in Malleswaram that has installed aerators in 4-5 taps per home, leading to savings of approximately 10,000 litres per day. While creating awareness for residents to install tap aerators took longer, the process of installing each aerator took less than five minutes. The solution is also cost-effective, as good-quality aerators are now available at Rs 50 to 70 per piece, with bulk purchases costing even less. 

While the concept of tap aerators is not new, there is a need for a WUC (Waterflow under Control) policy that would trigger public participation to install aerators on taps on their premises. Taps are the ultimate point of urban consumption as well as waste due to excess flow. A new “WUC Policy (Waterflow under Control)” that will set the maximum permissible flow rates (of 3-6 LPM) from water taps should be announced by the state. 

Similar to how the government imposes Pollution Under Control (PUC) norms for vehicles, the state government must introduce Water Flow Under Control (WUC) norms for taps. This would ensure that the maximum flow rate in taps would be regulated to 3 litres per minute for handwash taps and 6 litres per minute for kitchen taps, which is sufficient and does not compromise on functionality. This can be achieved through the use of tap aerators, which are readily available on the market.

The WUC policy and its implementation would strengthen the hands of BWSSB and the government, which cannot do it alone by investing in increasing the supply side. Once BWSSB notifies corporations, establishments, and resident welfare associations of the WUC policy and sets a compliance deadline of 60 days, everyone will be surprised at the speed of implementation. To give an example, Bengaluru is the IT capital of India, with around 15 lakh employees working out of IT companies housing a large number of hand wash taps. Assuming each employee uses a hand wash tap for one minute a day, an aerator (fitted to the tap) would result in savings of at least 10 litres per minute during usage. This would result in saving 15 million litres per day in the IT corridor alone. Given the high importance of CSR activities, we envisage a fast-track implementation of tap aerators in all their taps within 10 days, resulting in 15 million litres per day saved. With zero capital expenses by the government, this 1 WUC policy will effectively result in 15 MLD savings on Day 10 through the IT sector alone. Extrapolating this across other sectors can easily yield 100 MLD to 500 MLD in 100 days’ time. 

Further, BWSSB is empowered to create awareness and subsequently take punitive action against users for violating WUC norms. The water body can introduce expectations from RWAs to submit a self-declaration regarding tap aerators being fitted on their premises. 

Being the software hub of the country, it would be easy for the government to create and implement a tracking mechanism through a “Bengaluru WUC dashboard” to monitor the implementation of tap aerators in city buildings. 

The state must also make it mandatory for new buildings to have aerators pre-installed in taps, to receive the necessary clearances, and for tap manufacturers to only sell taps that are aerator compatible. 

This solution is a low-hanging fruit for the government to alleviate the water scarcity in Bengaluru. These can be implemented alongside more intensive measures such as lake rejuvenation, rainwater harvesting, etc. However, with the onset of summer, the state must act quickly and make tap aerators mandatory by announcing the WUC policy, which will enable an immediate saving of 100 MLD in 100 days at zero capital investment. 

(The writer is a waterpreneur and mentor at ABillionTaps and author of the book on project management, Steering Project Success)