The last quarter witnessed the publication of two promising news stories. Firstly, India achieved the target of 10 % ethanol blending in petrol, five months before the deadline. It is reported that the rise in ethanol blending in petrol from 1.5 % in 2014 to 10 % now has reduced carbon emissions by 2.7 million tonnes and saved Rs. 410,000 millions in foreign exchange reserves. Further, the government has now advanced the target of 20 % ethanol blended petrol by five years to 2025. A welcome development indeed from a sustainability perspective! Secondly, India has urged the Convention on Wetlands to expedite the designation of 26 wetlands in the country as Ramsar sites in addition to the existing 49 sites. This will help in bringing the tally of Ramsar sites to 75, in the platinum jubilee of India’s independence. Already, 5 additional sites received the Ramsar tag. This is also heartening news, as wetlands play a crucial role in flood control and act as sources of water, food, and fibres, supporting vulnerable, critically endangered species and threatened ecological communities.

Simultaneously, there are two disheartening news from climate perspective. First, the average maximum temperature over the Northwest and Central India for April this year has been the highest in the past 122 years and that the higher temperature regime continued in certain parts of Northern India during May and June months too. Secondly, the performance of southwest monsoon, which plays a decisive role in sustaining the livelihood of rural India, has so far been erratic. While there has been a delay in its onset, the month of July witnessed monsoon wreaking havoc in the Northeast and many parts of the India’s coastal regions, including Kerala, Karnataka, Telangana, Konkan and Gujarat. On the other hand, the data from Indian meteorological department shows that Western UP and some parts of West Bengal received 45-72% deficient rainfall till the end of July. Of course, monsoon’s erratic and traumatic performance is not new to India. The country has experienced the flood-drought syndrome many times during the past few decades. This syndrome is now tending to become acute as certain undesirable changes in the patterns in monsoon are discernible, along with its growing uneven spatial distribution, and its near-violent performance at few locations resulting in large damages.

Environmental scientists have largely attributed this to climate change and the rising global temperature phenomenon. One of the recent reports from the Intergovernmental Panel on Climate Change (IPCC) states “Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions”¹.

Owing to the continuing increase in population and growing industrialization and urbanization, the per capita availability of water in India has declined sharply from 6,000m³ in 1947 to 1,846 m³ in 2021. Despite the efforts made in building dams, reservoirs, wells, etc. for storage and use of water, the lower user efficiency has resulted in water-stress conditions in certain parts of the country. A NITI Ayog report highlights that nearly 820 million people in 12 river basins in India are facing high to extreme water stress situation. Referring to available estimates, the NITI reports states “Best estimates indicate that India’s water demand will exceed supply by a factor of two by 2030, with severe water scarcity on the horizon for millions.

The projected scenario for 2050 looks more agonizing. As per the report of National Commission for Integrated Water Resource Development of the Ministry of Water Resources, the water requirement by 2050 in high-use scenario is likely to be a 1,180 billion cubic metres (BCM), as against the present-day availability of 695 BCM.

How do we minimize the projected demand-supply gap in water requirement? Reducing wastage of water and improving water management efficiency are surely the best ways to lessen this gap. However, these will not suffice. Considering the exponentially growing demand-supply gap in water requirement, it is imperative to consider other avenues. According to TERI, India is able to fruitfully utilize less than one-third of the current precipitation³. Can we therefore not use rainwater harvesting and other innovative techniques on a massive scale to tap some part of this precipitation which otherwise is just going down the drains? Adoption of rainwater harvesting, and other techniques involving recycling and reuse of water are not only advantageous but also critically essential now. The inspiring and exemplary work of organizations like Tarun Bharat Sangh from Rajasthan under the leadership Mr Rajendra Singh and Pani Panchayat lead by Mr Vilasrao Salunke near Pune and many others have shown that painstaking work in water conservation can effectively tackle the perpetual shortage of water. “Pani Adva Pani Jirwa” – a slogan in Marathi can be used as an appropriate mantra of water management at national level.

This issue includes a distinctive feature on water conservation which includes two interesting case studies – one highlighting how rainwater harvesting technique was used in recharging ground water table and reducing the rainwater runoff and second on grey and black water recycling and reuse for a residential project.

Water scarcity can adversely affect industrial operations leading to undesirable effects on the national economy. The NITI Ayog report mentions that “industrial water requirement will quadruple between 2005 and 2030”². It is therefore essential for all sectors of Indian industries to prepare action plans and pursue the same to cater to the additional water requirement in the future. Such exercise is incredibly important for sectors that are crucially dependent on water for their operations. Take for example the energy sector. Currently, many land-based thermal power plants in India use fresh water for cooling. With water scarcity becoming acute in their region, these plants may face high water stress which could even adversely impact India’s energy security⁴. The industrial sector in India therefore needs to vigorously adopt water conservation methods and simultaneously evolve innovative techniques to reduce their water requirement.

The concrete industry in India uses substantial quantity of water during production. Unfortunately, no reliable data is available on the same. This issue includes a feature which presents a very rough estimate of such water requirement at the national level based on certain assumptions. The feature also briefly describes the measures that can be taken to conserve water in concrete production. It also advocates the combined use of a reclaimer and filter-press system in ready-mixed concrete operations. This will not only help in reusing the wash water but will also solve the sludge disposal problem, thus leading to zero discharge from RMC plants. Incidentally, an interview includedin this issue with a leading expert throws more light on the operations of the filter press.

We are happy to include a brief contribution from the research team of the Civil Engineering Department of IIT Madras describing a novel technology of extraction of high-quality recycled concrete aggregates from C&D waste using solar energy.

Technological innovations are bound to play crucial role in humankind’s efforts to mitigate the harmful effects of climate change. LCCF would certainly welcome worthwhile contributions on such topic.

References