Our river beds are mined and mountains are being destroyed continuously to build new roads and restore the existing ones all over the country. Indiscriminate & excessive mining can lead to deforestation, soil erosion and water pollution. This can result in the destruction of habitats for wildlife, which can have serious ecological consequences in the long term. However, sustainability is an aspect that is not often considered when carrying out civic work in Chennai and across the country.
While infrastructure development is crucial to achieving economic growth, what we are getting to see is temporary cosmetic makeovers. There is no clear vision or conviction on the part of the local administration to deliver roads or other basic infrastructure that will last for a long period of time and prevent the need for more destruction to secure resources.
Creating sustainable roads in Chennai
These days the roads across our cities are being milled and resurfaced. The local administration must make it mandatory for all road contractors to recycle the milled debris as is being done in other developed countries.
During our discreet conversations with the contract workers, we were told that the milled debris is being sent to the landfills because of the very high costs incurred in transporting and recycling the same. Using advanced technology available to recycle the milled debris on the spot is the way forward.
New road surfacing techniques like Full Depth Reclamation can go a long way in improving the quality and life of the roads within the city and elsewhere. The damages caused to the roads within weeks or months after they are resurfaced are not only due to the quality of the asphalt mix but also due to the underlying problems with the base of the roads.
FDR will not only help in recycling the full depth of the existing road but also strengthen the base and ensure our roads last for a longer period of time.
While this technique has been adopted by corporations in other states within our country, we are left wondering why this is not being adopted by the Greater Chennai Corporation.
Checks and balances must be introduced to curb the widespread corruption as well as the deep-rooted nexus between officials, politicians and contractors. The minimum guarantee period for the resurfaced roads must be increased from 3 years to 10 years or more. It is possible to build long-lasting world-class roads across the city with the necessary political will.
Let us take Downing Street in London as an example, the height of this road has remained the same over the last 300 years as per media reports. In Chennai, the height of the existing roads has increased by over 3 to 4 feet in the last 2 decades.
If GCC can put in place a plan to mine all the existing roads by a couple of feet as a one-time measure, they will have enough, if not more, blue metal to resurface the roads across the state. This will also help save the houses which are flushed with the surface of the road from inundation during the monsoon.
Read more: Explainer: How are roads in Chennai laid?
Dealing with construction debris in Chennai
During the construction of Metro Rail Phase 1 in Chennai, the debris collected during the underground Tunnelling work was dumped into the Villivakkam Lake. The 2014 deluge was an eye-opener when the localities around the Villivakkam lake were entirely engulfed with flood water. But for the intervention of NGOs like Arappor Iyyakkam, it would have been impossible to reclaim the water body and restore it.
Despite all efforts, they were able to reclaim only 70 to 75% of the lake. The erstwhile local administration had decided to dedicate a portion of the lake to be developed as an amusement park. A hanging glass bridge across the lake has been put in place and is likely to be opened to the public.
After the National Green Tribunals intervention, the current administration has planned to extend the water spread area within the lake.
The tunnel boring work for Metro Rail Phase 2 is being taken up at several locations across the city. The onus is entirely on the people to keep a close watch on where the debris is being dumped. We just cannot afford to lose any of the remaining water bodies or marshlands.
All the mud, rocks and sand being excavated must be recycled properly. In the name of infrastructure development, the administration cannot be seen playing with nature. The government authorities must bear in mind the massive destruction we had to face after the tsunami and the deluge in and around Chennai.
Read more: Not just Villivakkam Lake, apartments and malls too can benefit from our technology: BARC scientist
Building sustainable infrastructure in Chennai and beyond
Reducing consumption and use of renewable or recyclable resources should be encouraged.
Illegal mining of beach sand by private players to extract the minerals was rampant along the coastal areas of Tamilnadu & Kerala until 2016. The beach sand in these belts contains various minerals viz: ilmenite, zircon, rutile, garnet, sillimanite, leucoxene, monazite etc. According to reports small quantities of thorium and uranium were also being extracted from these minerals.
In the year 2019, the Central Government issued a notification prohibiting the grant of atomic mining rights to the private sector which was a step forward in the right direction.
Large quantities of sand are being extracted from the riverbeds causing environmental degradation. While the government of Tamil Nadu has put in place a system to supply river sand online, there are widespread allegations that huge quantities of sand are being mined and sold offline to the neighbouring states with duplicate bills. This would not have been possible but for the deep nexus between the officials, politicians and the sand mafia.
Destruction of the hills and mountains to produce blue metal gravel and M sand must stop.
Depletion of natural resources occurs when resources are taken from the environment quicker than they are replenished. While renewable resources can be replenished, there is a finite amount of non-renewable resources. The rate of depletion of natural resources is growing due to the rising population.
Sustainability campaigns aimed at informing people about the value of resource management will go a long way in addressing the risks of environmental degradation.
The government must put in place a plan to reclaim and reuse the thousands of tonnes of construction debris which is being illegally dumped in the marshlands and water bodies.
The use of industrial by-products as an alternative fine aggregate in the preparation of concrete is a sustainable solution to regulate excessive mining and disposal of industrial by-products. The inclusion of recycled ceramic, plastic, rubber, glass, bricks, concrete debris, and copper slag aggregates is being considered. Plastic and rubber are already being used successfully while resurfacing the roads with Asphalt by the local bodies within our state and elsewhere in the country.
Understanding the physical and chemical properties of alternative fine aggregates helps to identify the possible variations in the fresh and hardened characteristics of the concrete and the research studies are going on.
The depletion of natural resources can be a threat to our existence and it’s high time we take notice of this. If all our natural resources are lost, it would be a challenging task for our future generations to sustain themselves on this planet. We must bear in mind that natural resources cannot be produced or generated by human beings, we must learn the art of using, reusing and altering the various resources even as we strive to build better cities.