JOIN USLake connectivity was once Bengaluru’s pride, its time-tested pillar of water self-sustainability. Designed in cascades from higher to lower elevations, the lakes allowed excess water to flow from one water body to the next along a natural gradient. But development destroyed this system in the City’s core and massacred the linking wetlands. Do the lakes on the city’s periphery now stand a chance?
The signs are bleak, the telling instance of the Yele Mallappa Shetty lake near Hoskote sliced into two by the Old Madras Road offering no such hope. Satellite imagery clearly shows this water body’s organic connection to the distant Hebbal lake. From Hebbal to Nagavara to Kalkere to Maragondanahalli, the link runs into the Mallappa Shetty lake, only to be disrupted by a highway.
The link was already broken on the wetlands of Nagavara lake, where a tech park emerged to disrupt an ecosystem that had ensured a natural flow of water for centuries. Obviously, the land developers had no clue or inclination to sustain a system that acted as reservoirs to impound rainwater, store it for future use and recharge the ground water.
For the record, the city’s topography has given it three main valley systems: Hebbal, Koramangala -Challaghatta and Vrishabhavati, along each of which the lakes have formed a chain of reservoirs. Cascading streams link the chain. In the city’s core, stormwater drains have replaced these streams. Severely encroached and fed with sewage, the drains run into lakes, first polluting them and eventually killing the water bodies.
Devastation in the periphery
In the City’s periphery, this model of destruction is being replicated with devastating effect. As Umesh R, a landlord in Kadugodi explains in chilling detail, the streams and wetlands sustaining the lakes are getting filled up fast. “Mud excavated for large apartment complexes are dumped into these low-lying spots. The flow has stopped. The water table has sunk from 140 feet a few years ago to more than 1,000 feet now.”
The system of checkdams that helped in irrigating farms in and around the lakes has completely disappeared. Points out Umesh, “Everything has been filled with silt. Earlier, we used to get water even from Hebbal lake, uninterrupted. It would feed hundreds of acres of paddy fields.” The landlord claims he and a few local environment activists had approached the local MLA to widen the stormwater drains and streams. But the attempts have been in vain.
Once the linkage system is deliberately disrupted, real estate developers take over. Documents are fabricated, hands are greased. In due course, huge apartment complexes and layouts have emerged.
A prominent property developer’s blatant takeover of 72 acres of wetland between the Bellandur and Agara lakes for a SEZ is just one instance. Rapped by the Karnataka Upa Lokayukta, the BBMP had to order stoppage of the project construction. Official reason: The project had no approval. But the developers had obtained layout approval from the Karnataka Industrial Area Development Board (KIADB), subject to clearance from the local authorities.
The Lake Development Authority (LDA) had observed that such a project built on the catchment area of the Bellandur lake would severely affect the lake and its surrounding ecosystem. Although the wetland was acquired from farmers through KIADB, LDA wanted the Board to reclaim part of the land to be restored as a valley zone. As it emerged later, this was clearly ignored.
Takeover of wetlands
Hundreds of truckloads of construction debris were dumped on the Bellandur wetlands for months. No official winked at this daylight operation. Spot visits reveal that temporary and even permanent-looking residential and business establishments have emerged here. Multi-storey residential complexes have risen on the beds of both Bellandur and Varthur lakes on the City’s periphery.
In May 2013, a study by the Centre for Ecological Sciences, IISc, had concluded that the SEZ around Bellandur lake will trigger demand for at least 4.58 million litres of water per day, bring in 14,000 vehicles, besides leading to irreversible damages to the surrounding ecosystem. Topographical alterations in the lake’s vicinity, the study found, will also increase the potential for flooding.
But rescuing lakes and wetlands from just the real estate developers will not suffice, reason ecologists. Lakes cannot be rejuvenated by cutting off the inlets and remodelled only for recreational and aesthetic purposes. The renovation of Nagavara lake cannot be a model to emulate. Explains H S Sudhira, a researcher from Gubbi Labs, “The City’s water bodies need to be reimagined. We should see lakes/tanks as collectors of water, a consequence of various small streams. They cannot be seen in isolation.”
This thinking is yet to percolate down to lake developers even in the new BBMP areas. Take for instance, the Halanayakanahalli lake on the downstream of the Bellandur lake, and off Sarjapur Road. As Dr Rohan D’Souza from the Ashoka Trust for Research in Ecology and the Environment (ATREE) points out, the village panchayat that controlled the lake of over 40 hectares focused only on beautification. “They aren’t looking at lake connectivity, but only on superficial aesthetics. This won’t help the water body.”
Need to reimagine
If in the past, tanks and lakes fulfilled the roles of storage and washing, they need to be reimagined as drinking water sources today, says Sudhira. “By covering the drains, and resorting to what we call ‘stream burial,’ the BBMP is cutting off supply of oxygen from direct sunlight.” This aids methane formation in the drains, and also cuts off rainwater. The flow to the lakes is disrupted yet again.
The LDA model too is skewed, adds D’Souza. “The conversion of linear bunds to ring bunds leads to minimal overflow of lake water into the wetlands. This hastens the process of lakes becoming standalone bodies,” he elaborates. The Rachenahalli lake’s apparent revival by this model might just be short-lived. The message is clear: A lake just cannot survive without its surrounding ecosystem and natural linkages to water bodies downstream. A model that ignores this has no business to be there.