The hottest year in recorded history has just passed, and we face record levels of water scarcity—across the country, and in Karnataka in particular. This is alarming, if for the reason that This calls for introspection about what could have been done differently, and what can be done now.
Dr. T.V. Ramachandra is an expert in the field of water conservation, and a frequent public commentator on our ongoing water-scarcity related problems. He will talk to us on Thursday the 27th of April, at 5pm, at Kanada Auditorium, JNCASR, about the enormous challenge facing us and how we can overcome it. An abstract from the speaker follows.
Abstract
Water is one of the fundamental elements of the universe from which early life originated millions of years ago on earth. Every life on the earth is primarily dependent on water which hosts innumerable aquatic species from single cell creatures to gigantic blue whales. As the evolution of human took place, civilized human settled down on the fertile river banks. In other words, river banks are the motherhood for civilized human and most of the civilization around the world. These river or lake banks gave water for drinking and also for cropping along with mineral rich soil. Civilized men knew the importance of water and respected these water bodies. However, deterioration of traditional water harvesting practices in most parts of burgeoning Bangalore has resulted in the inequity in water distribution and growing water scarcity, which has escalated water conflicts during the 20th century. Irresponsible management of natural resources is evident from (i) sustained inflow of untreated sewage and industrial effluents; (ii) dumping of solid waste (with 70% being organic); (iii) transport of untreated wastewater in storm water drains (water drains are essentially arteries of a landscape carrying water), etc.
Unplanned rapid urbanisation during late nineties, witnessed large-scale unrealistic, uncontrolled developmental activities in the neighborhood of wetlands. Land use analysis in Bangalore City shows 1005% increase in urban (built-up) area between 1973 and 2016 (i.e., from 8.0% (in 1973) to 77% (in 2016)) with a decline of 88% tree cover and 79% water bodies. Land use prediction using Agent Based Model showed that built up area would increase to 93.3% by 2020, and the landscape is almost at the verge of saturation.
Average annual rainfall in Bangalore is 787 mm with 75% dependability and return period of 5 years. Catchment wise water yield analysis indicates the total water available is about 14.80 TMC. Domestic demand of water (at 150 lpcd) is 20.05 TMC per year (1573 MLD). This means about 73% of Bangalore’s water demand can be met by efficient harvesting of rain water. Quantification of sewage generated shows that about 16.04 TMC (1258 MLD) of sewage is generated in the city. Sewage treatment with complete removal of nutrients and chemical contaminants is achievable by adopting decentralized treatment plants similar to the success model (secondary treatment plant integrated with constructed wetlands and algae pond) at Jakkur lake. In addition to this, water available with efficient rainwater harvesting is about 14.8 TMC. This means that total of 30.85 TMC of water is available annually to cater the demand of 20.05 TMC, provided the city administration opts for decentralized optimal water management through (i) rainwater harvesting by rejuvenating lakes. The best option to harvest rain water is through interconnected lake systems, (ii) treatment of sewage generated in households in each locality (opting the model at Jakkur lake – STP (Sewage Treatment Plant) integrated with constructed wetlands and algal pond; (iii) conservation of water by plugging the pilferages (due to faulty distribution system); (iv) ensuring water supply 24×7 and (v) ensuring all sections of the society get equal quantity and quality of water. Rejuvenating lakes in the region helps in retaining the rain water. Treating sewage and options to recycle and reuse would minimize the demand for water from outside the region. The analysis illustrates that the city has at least 30 TMC (Bangalore city) of water, which is higher than the existing demand (20.08 TMC, at 150 lpcd and 2016 population), if the city adopts 5R’s (Retain, Rejuvenate, Recycle, Reuse, Retain and Responsible citizens). In order to enhance the water retaining capability in the catchment, it is essential to harvest rain water and undertake large scale watershed programme (soil and water conservation). Lakes are the optimal means of rainwater harvesting at community level.
Reference: Bangalore’s Reality: towards unlivable status with unplanned urban trajectory, Guest editorial, Current Science (June 2016).
About the Speaker:
Dr. T.V. Ramachandra, FIE, FIEE (UK) obtained Ph.D. in Ecology and Energy from Indian Institute of Science. At present, Coordinator of Energy and Wetlands Research Group (EWRG), Convener of Environmental Information System (ENVIS) at Centre for Ecological Sciences (CES). During the past twenty years he has established an active school of research in the area of energy and environment (http://ces.iisc.ernet.in/energy). He is a member of Karnataka State Audit Advisory Committee (2014-16). He was a Member of Karnataka State level Environment Expert Appraisal Committee (2007-2010), appointed by the Ministry of Environment and Forests, Government of India and a member of Western Ghats task force appointed by the Government of Karnataka. He is a recipient of Johny Biosphere Award for Ecology and Environment (2004), Satish Dhawan Young Scientist Award, 2007 of Karnataka State Government and Best ENVIS award (thrice – 2015, 2014, 2004), the Ministry of Environment, Forests and Climate Change, Government of India, and recently Our Bangalorean, 2016 award (Namma Bengaluru Foundation).
He is an Elected Fellow of the National Institute of Ecology (2011), Indian Association of Hydrologists (India; 2006), Institution of Electrical Engineers (IEE, UK; 2005), Institution of Engineers (IE, India; 2003), and a Senior Member, IEEE (USA; 2000) and Association of Energy Engineers (USA; 2000).
TVR’s research interests are in the area of energy systems, renewable energy, energy conservation, energy planning, aquatic ecosystems, biodiversity, ecological modelling, geo-informatics, environmental engineering education research and curriculum development at the tertiary level. He has published over 264 research papers in the reputed peer reviewed international and national journals, 52 book chapters, 302 papers in the international and national symposiums as well as 17 books. In addition, he has delivered a number of plenary lectures at national and international conferences. Publication “Milking diatoms for energy” is seminal work in biofuel research evident from reports in Scientific American, BBC, national dailies, etc.
He has guided 110 students for Master’s dissertation and nine students for Doctoral degrees. TVR has travelled widely across the country for field research and also for delivering lectures at Schools and Colleges. He has taken initiatives through biannual symposium (popular as Lake series), training programmes and workshops for capacity building at various levels. Details of the Lake Symposium are available at
http://wgbis.ces.iisc.ernet.in/energy/lake2016/index.php
Dhwani @ JNC 