Bengaluru has a ‘concrete’ plan for uncertain weather

At a time when the city is experiencing erratic rainfall, doesn’t it have a climate emergency action plan yet? Yes, more concrete if you wish, as the civilian authorities would have.

But even minimal rain is a nightmare for people living in low-lying areas or next to storm water drains – the city’s late Sunday night thunderstorms are an example.

A large number of families are living in fear that water may enter their tiny houses and destroy everything that comes in their way.

Experts suggest that instead of more concrete structures, officials should focus on non-structural solutions as much as they do with structural measures to reduce climate change-triggered flooding.

So, what are non-structural solutions?

These include minimum 60 mm of rainwater harvesting facility in each of the 20 lakh buildings. BangaloreGroundwater recharging pits in many open spaces including rejuvenation of shoulder drains and lakes to name a few.

According to conservation experts, the two above solutions – if implemented on a large scale – can stop about 80% of rainwater from flowing into Rajkaluwe and prevent flooding in low-lying areas.

This is absolutely possible because the annual budget of the municipal corporation alone is more than Rs 1,000 crore, which is just for stormwater drainage improvement.

As experts point out, encouraging families to provide rainwater harvesting facilities is one way to encourage a large population of the city to conserve water.

rain water as a resource

Dr. Srinivas Reddy, Former Director Karnataka State Natural Disaster Monitoring Center (KSNDMC) was of the view that no structural measure can prevent floods in the city. “What should be done to reduce the amount of water flowing in the roads and drains. We need to look at rainwater as a resource and conserve it,” he told BM.

According to Reddy, structural measures like re-modelling and de-silting can only increase the carrying capacity of drains. “Floods occur in some parts of the city even when the rainfall is less than 10 to 20 mm. This is the extent of concretization which has happened due to no space for water to drain out or recharge in the ground,” explained Reddy.

S Vishwanath, Founder rain water clubSuggested a change in policy. “Each building shall ensure that at least 60 mm of rainfall does not leave its plot. Water must either be stored or stored. By doing this they will be able to save a lot of money and prevent floods,” he said.

He said a 6,000-liter water tank or a 20-foot deep sump is enough to store the water received from 60 mm of rain. “These facilities are already present in most of the buildings. What the government needs to do is to encourage people to take up rainwater harvesting through incentives and mass campaigns,” he said.

Vishwanath was not happy with the way the roads and shoulder drain have been designed. “Both roads and drains need to be integrated. What we are seeing is the worst form of engineering. The water does not go into the drain at all,” he said.

He suggested making two to five feet deep rings inside the drains so that the water could seep. Another suggestion given by a water expert is the use of open spaces including large parks such as Cubbon Park And Lalbagh The site of water infiltration by diverting water from the road.

traditional approach

Leo Saldanha, Coordinator environmental support group (ESG) wanted the municipal bodies to treat the lakes as irrigation tanks instead of converting them into parks.

“Irrigation tanks – now called lakes – are a technique that is about 6,000 years old, dating back to the pre-Vedic Harappan period, when people discovered how to sustain farming during the non-monsoon period. how to collect rainwater and surface runoff. This perpetuated hundreds of urban centers. The same idea continued for centuries to our time, where lakes and their canals (rajkaluwe) store rainwater, ground water rechargeSupply drinking water, and also act as a buffer against floods,” he said.

He said that the municipal bodies have allowed pollution and encroachment of these water networks. “In their folly, they concretize canals and ring-bund lakes, leaving no room for water that floods our paved and paved roads and areas destroying lives, livelihoods and property. It is really necessary to be smart and rely on age-old wisdom to let water stay, flow and nourish life. Not the cause of death and destruction,” he said.

So far, the Bruhat Bengaluru Mahanagara Palike (BBMP) has spent around Rs 2,000 crore to build a concrete retaining wall over a 389-km storm water drain network. Similar work is currently underway on a 75-km network. In addition, the civic body has appointed a contractor to pay Rs 31 crore per annum for 400 km of drainage.

Additional Chief Secretary, urban development department, Rakesh Singhdid not respond to calls from BM.