“Carbon footprint” is a direct measure of greenhouse gas emissions caused by a defined activity and can demonstrate global warming effects. Urbanisation and population growth have forced governments to provide clean water that can meet people’s expectations in both quality and quantity. One way to combat the depletion of shallow wells is to drill to deeper aquifers; the main disadvantage of this approach is the lower quality of the obtained water, and therefore need for a more complicated treatment process. Along with depth, we are going to a distance as well. Bengaluru gets water from Kaveri river from over 130 kms away. This is called ‘Long Distance Water (LDW)’. Most of the metropolitan establishments have switched to LDW.

Typically, the traditional sources of water, like shallow wells, local streams, neighbourhood lakes etc are always having low carbon footprint. This is primarily due to lower energy requirements for distribution and quality management. Pre 1974, cities like Bengaluru relied primarily on a number of lakes within the city for potable water distribution. Thus the Carbon Footprint was very low.

Today, the majority of water used in Bengaluru city comes from 2 carbon intensive sources; Kaveri Basin & Borewells. Borewells are over 2000 feet deep and require a multi-staged pumping mechanism to lift the water to ground level. The Kaveri basin supplies water into the city from over 130 kms and nearly 900 ft against gravity. BWSSB is one of the largest consumers of energy in Karnataka which is significantly generated using Coal at RTPS (Raichur Thermal Power Station).

Sustainable Development Goals 30 (SDG-30) proposed by the United Nations says that for any city to sustain, the long distance water cannot come from over 30 kms. As countries around the world set ambitious net zero energy commitments in order to avert the most catastrophic effects of climate change, it becomes crucial to focus on mitigating the carbon emissions of sectors that play a major role in everyday life and have correspondingly higher impacts on the environment. The water sector is one of those.

Ray of hope, Bengaluru was a city of Lakes, but today, it is a city of dead lakes. In the interest of Climate Change and reduction of the hidden carbon footprint of the water, the civic bodies & government should try to augment Lakes towards potable water supply, rather than concentrating on even longer distances (Like getting Sharavathi Water to Bengaluru, which is a bigger disaster).