Sanjana Alex

Algal growth in Rachenahalli lake Pic: Girish Varma One of the characteristic features of a lake is its colour. You may have noticed that the water in many lakes in Bengaluru is green, and not blue, as you might have imagined it to be. This is due to the presence of algae. Algae are microscopic plants that contain chlorophyll which is the pigment that gives it a green colour.

Polluted lakes are contaminating Bengaluru's open wells and shallow borewells. Pic: Aparna Madamanchi Due to rapid urbanisation and unplanned development, Bengaluru’s groundwater is getting increasingly contaminated. This issue requires urgent attention as approximately 40% of the city’s population depend on groundwater (borewells, open wells and tankers) for their daily water needs such as drinking, cooking and bathing.

Traditionally, Bengaluru’s lakes stay dry for a couple of months, and fill up during the monsoons. This made it easier for potters, brick makers and farmers to collect silt from lakes. But due to climate change, rapid urbanisation and unplanned development, more lakes have been drying up for longer periods of time. Reliable, useful journalism needs your support. Over 600 readers have donated over the years, to make articles like this one possible.