I t is a water body that spans 180.4 hectares and is the second largest lake of the garden city; it has the dubious distinction of being the most polluted lake of Bengaluru, with domestic sewage, industrial effluents and wastewater finding their way unhindered into its precincts, while the neighbourhood watches helplessly, struggling to find a solution.
We are talking about Varthur Lake, which is advocated by experts to be in stasis for another two-and-a-half years till the interventions initiated at Bellandur Lake are completed. The lake, not having been desilted for the last 40 years, accommodates a staggering 4.49 million cubic metres of both sludge and sediment.
While the neighbourhood realised this status cannot continue and has taken steps to initiate desilting using dredging as a process, with financial assistance from corporate house, Mineral Enterprises Ltd., the larger question of rejuvenating the lake and the role of wetlands around it required understanding.
A participatory planning workshop was recently held by Sensing Local-Living along with Biome Trust, Varthur Rising and Whitefield Rising, bringing together the various stakeholders to discuss and arrive at the appropriate guidelines for designing the Varthur Lake wetlands. The objective was to adopt the right approach for the development of the wetlands around the lake, arriving at the right size, depth, capacity as well as appropriate type, so as to impact positively its biodiversity.
The workshop witnessed representatives from four neighbourhoods, presenting their experience with rejuvenating their neighbourhood lake. These included Agara Lake, Puttenahalli Lake, Jakkur Lake and Lower Ambalipura Lake which had been revived with the active involvement of the local neighbourhoods and currently feature as fine examples of what citizen involvement and partnership can do to the city’s waterbodies. The workshop also had a lengthy presentation by T.V. Ramachandra, professor from IISc, on various components of wetland design, its type, biodiversity and the plant typologies best suited for it.
Sharing the neighbourhood’s experience of reviving the Jakkur Lake, Anupurna Kamath said, “We adopted the lake in 2015 and currently there are 7 acres of wetlands around it with plant species such as hyacinth, typha, umbrella plant, and alligator weed. Three inlets form the source of water for the lake, with 15mld of treated water entering through the wetlands.”
While the wetlands ensure the water entering the lake is clean, she pointed out that the fish in the lake and the fishermen further aid in maintaining the waterbody. The 160 acres of the lake body including the wetlands incidentally house over 5,000 trees, according to her, offering a fine community conservation model, supporting many species of birds, butterflies and bees.
Usha Rajagopalan had a similar story to relate on rejuvenation of Puttenahalli Lake which spans 13 acres. “When we took over maintenance of the rejuvenated lake, we were in total ignorance of the role wetlands play in keeping the lake clean”, she stated. Currently, the lake, fed by treated water passing over one acre of wetlands through eight inlets, is a witness to family gatherings from the neighbourhood, the community participating and connecting with nature. “It is this sense of ownership the neighbourhood has that ensures the lake is maintained”, she adds.
The Lower Ambalipura Lake which includes four lakes spread over 7 acres, which includes 2 acres of wetlands that abound in fruit-bearing trees, is likewise maintained by the neighbourhood since its rejuvenation a decade ago.
The Agara Lake rejuvenation had a different tale to relate. While this had a well-defined wetland to begin with, where the wetlands form 26 acres and the main lake amounts to 46 acres, a legal battle is ensuing on the leasing. Two inlets for water prevail over the wetlands, the garbage inflow effectively addressed with filters placed in the wetlands.
“The source of water is only rainwater as we open the inlets only during rains”, says Kavitha Reddy, who has been campaigning and monitoring rejuvenation and maintenance of the lake along with the local community. She however adds, “the excess treated water from the neighbourhood apartments let into the wetlands can form a good source of water for the lake.”
Given the beauty of the expansive wetlands, not only multiple varieties of bird species frequent, but thousands of visitors from the neighbouring community enjoy the space, she points out.
The individual experience sharing enabled the workshop to come up with noteworthy suggestions which could help steer the Varthur Lake rejuvenation in the right direction. It was pointed that though the importance of wetlands in Bengaluru’s lake ecosystem is not grasped fully by citizens and government, a welcome shift in perspective has now occurred in viewing wetlands no more as encroachment but as an integral part of the lake’s ecology.