Concrete problem in Bengaluru | Deccan Herald

As we enter another monsoon season, Garden City, Bengaluru, is fast becoming a tangible capital, as is the rest of the country.

Name any development/infrastructure project and the likelihood that it involves large amounts of concrete. White roads, Rajakalov reclamation, smart city projects – all are exercises in engineering in concrete.

The fact that we just survived a pandemic and need to protect the planet by engaging in less polluting building methods seems to have been forgotten.

Over the past century, concrete has offered city governments (and the engineers who manage them) an inexpensive and simple way to build cities. Dams, bridges, harbors, city halls, campuses, and shopping malls are all testament to the power of concrete engineering. Concrete politics finance the campaigns of politicians. The result is the relationship of politicians, bureaucrats and construction companies to the perpetuation of environmentally and socially questionable infrastructure projects and “cement festivals”.

Concrete is one of the most polluting materials on earth. However, it is the most widely used material after water. It is the language of engineering and modern development in most urban centers. If the cement industry were a country, it would be the third largest emitter of carbon dioxide in the world, at about 2.8 billion tons, surpassed only by China and the United States. It smothers vast tracts of fertile soil, chokes rivers, clogs habitats, and desensitizes us to what happens outside of our urban castles.

The problem with concrete is that while it has been resilient to nature for decades, events like the annual floods in Bengaluru and Chennai are made more dangerous because concrete streets cannot absorb rain like floodplains, and rainwater drains are woefully insufficient to cope with new . Extremists from a turbulent climate.

Concrete also amplifies the harsh weather it protects us from. It is responsible for 4-8% of the world’s carbon dioxide. Other environmental impacts include absorbing nearly a tenth of the world’s industrial water, which increases the heat island effect by absorbing the sun’s heat and trapping gases from vehicle exhaust and air conditioning units, exacerbating the problem of silicosis and other respiratory diseases. .

Limestone quarries and cement factories are also sources of pollution, as are trucks that transport materials between them and construction sites. The sand mines, which have destroyed much of the world’s beaches and riverbeds, are also on a catastrophic scale. The biodiversity crisis is driven by the rapid destruction of nature and the development of industrial areas and residential communities. The benefits of concrete are now being outweighed by its environmental negativity.

There is only so much concrete that you can put in well without harming the environment. Today, unfortunately, traditionalists and environmentalists are routinely ignored. The engineers responsible for producing master plans and detailed planning reports pay little attention to the classic aesthetic ideals of harmony with nature and an appreciation of the environment. In Bengaluru, we are now drowning in a river of concrete sludge. We see floods with only one day of rain – mostly due to the solidification of banks of water bodies and hillsides (in the name of preventing floods and mudslides) and the destruction of mangroves, self-cleansing streams, storm resistance swamps and flood-preventing forests.

The unfortunate truth is that every new government announces major infrastructure projects. Concrete construction and infrastructure development are now synonymous with the rise from a developing country to an anticipated superpower. China’s real estate sector — roads, bridges, railways, urban development and other cement and steel projects — accounted for a third of its economic expansion in 2017 and used nearly half of the world’s concrete. But, like the United States, Japan, South Korea, and every other “evolved” country before it, China has reached the point where simply pouring concrete does more harm than good. In India, we are on the cusp of expanding our obsession with concrete. If we act quickly, we may be able to avoid the more dire consequences of the overuse of concrete in city building.

Some cities are trying to fix the bug. Seoul removed highways along the Cheonggyecheon Stream, Seattle replaced streets with permeable sidewalks, and Zurich mandated that all flat roofs in the city be green.

The concept of “sponge cities” is being adapted into the infrastructure of cities such as Baicheng, Qian’an, Shanghai, Shenzhen, etc., in China with a goal of 80% urban areas to absorb 70% water by 2030. Instead, only impermeable concrete and asphalt , Sponge cities need contiguous open green spaces, interconnected waterways, canals and ponds that can naturally trap and filter water, enhance urban ecosystems, green roofs, porous roads, sidewalks, and drainage systems that allow water to flow into the land and be recycled.

Bengaluru is close to the tipping point. We need to re-engineer our use of concrete to save ourselves.

(The writer is a Bengaluru-based urban planner)

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