It is a scene that we are increasingly seeing and helplessly so - cities turning into concrete jungles, dried-up lakes and river beds. Where the water bodies do exist, the water polluted to the hilt and the ecology around the rivers shrinking with groundwater dipping to unimaginably low levels. Is there a way to reverse this, restore ecology, make sustainable cities a reality?
ASSOCHAM GEM Karnataka Chapter, as part of the ASSOCHAM Realty and Sustainability Confluence Expo and GEM Awards, hosted a panel discussion on ‘Ecological Restoration’ where experts spoke on the ecology of Bengaluru city and its peripherals, exploring ways of altering the prevailing state.
Blame it on construction
Almost 50 per cent of the climate change can be attributed to construction and the requirements it raises where steel is an integral part, contended Prabhash Chandra Ray, MD, Karnataka Mining Environment Restoration Corporation. He pointed that iron ore, which is the basis of steel, is being mined at the rate of 35 million tonnes per year in Karnataka and this is required to be doubled to meet the growing construction needs.
“Irresponsible mining activity led to not only the destruction of ecology around the mining area but the air around the villages too gets polluted. Our focus is not only responsible mining and ecological restoration on completion but also the manner in which the mined ore is transported as this again is a source of pollution,” he added.
Polluting freshwater
Mindless pollution of waterbodies destroys marine life, a serious environmental concern. “Close to 15,000 varieties of freshwater fish, which forms 45 per cent of the fish species, live on 1 per cent of the earth surface which holds fresh water and when these waterbodies are polluted, the freshwater fish which form an important part of the ecosystem, perish,” stated Naren Sreenivasan, Conservation Biologist. He drew attention to the humped-backed Mahseer fish, one of the biggest of the Mahseer species. “Because of the heavy chemical and metal effluents and sewage pollutants in the Arkavathy that finally joins the Cauvery, this species which is endemic to the Cauvery basin is now facing near extinction.”
The Arkavathy is a typical example of pollution being carried downstream, explained Lingaraju Yale, Director, River Rejuvenation, Art of Living. “Bengaluru city is on a ridge and 400 sq km of the city area is spoiling 4,000 sq km of the drainage system in the downstream peri-urban area. Sewage travelling from upstream contaminates the natural streams and lakes downstream even when the individual layouts in the peripheral areas effectively address pollution. We need to address the pollution at the source in the upstream region through sewage treatment plants before they contaminate the downstream section.”
Multiple watersheds and recharge wells
He also advocated dividing the city into multiple watershed regions to identify the type and source of pollution and laying the responsibility on the polluter to arrest it. Concurring with Yale was water expert S. Vishwanath, Advisor, Biome Environmental Trust. “The city is dependent solely on the Cauvery to meet its daily requirement of drinking water and it is the city’s responsibility to ensure it is pollution-free and also take care of its catchment areas.” According to him, besides the city’s lakes and tanks which are purely biological, ecological and social spaces, the still prevailing open wells of the city can become part of our water and ecological restoration. “If the city digs a million recharge wells, each typically being three feet in diameter and 20 feet deep, the rainwater collected on rooftops can be filtered and let into these wells where they perform the function of recharge as well as discharge wells if the aquifer condition permits.”
Vishwanath further pointed that only 3 to 8 per cent of rainfall in the city percolates into the aquifers but through recharge mechanisms. “We can increase this to 50 to 60 per cent, preventing flooding as well as increasing groundwater levels.” He drew attention to the seven old open wells in Cubbon Park which were revived to provide 1 lakh litres of water to the park which otherwise would have been sourced from the Cauvery water. Currently 220 acres of the park has 70 recharge wells to increase groundwater levels and this is a significant part of ecological restoration.
Wastewater as a resource
Mr. Vishwanath also pointed to wastewater as a source of freshwater. “STPs not only clean the sewage water, the sludge can be used as manure and to generate energy. The treated water, when passed through wetlands, gets cleaned further before finally being let into the lakes.” These lakes and streams become a source of healthy freshwater for marine life, a bird paradise, with the entire biodiversity of the area being revived. The treated water is also a source of irrigation when let into streams flowing through villages.
“Opting for a number decentralised STPs across the city to treat every drop of the 1600 mld of wastewater generated and discharging the clean water into lakes, streams and wetlands would not only automatically push up groundwater levels and address the biodiversity, but wipe out the issue of pollution in the Arkavathy and eventually in the Cauvery,” summed up Mr. Vishwanath, bringing to the fore the potential resource the city’s wastewater generation poses.
Grow it on concrete
While water is the life force, to sustain life, food is basic necessity and that food is connected to the extent of greenery prevailing in and around the city. Stressing on bringing back the greens even on concrete spaces was permaculturist Binay Kumar Singh, using the techniques of permaculture. He contended that lack of soil or open ground is no deterrent to usher in the greens. “Every household produces waste and 60 per cent of it is wet waste which can be turned into compost. The terrace of each house is potential ground for cultivation using this compost. When gardens are turned into edible ones from the present ornamental leaning, transformation automatically happens, ecological restoration effortlessly materialises”, he explained.
