Change in stormwater mgmt need of the hour, say experts

Bommai said on Monday that he has instructed the officials to see to it that water is drained out from the inundated roads at the earliest.

With continuous rains causing flooding in low-lying regions of Bengaluru, the urban experts have called for a change in the way the storm water in the city is handled. Flooding has left a trail of destruction and suffering for people living in low-lying regions of the city and other places where drains and lakes have overflowed into homes and basements.

People pull a car through a waterlogged road following torrential rains in Bengaluru. (REUTERS)

The rains have again exposed chinks in Bengaluru’s poor quality of infrastructure and planning, with Karnataka chief minister Basavaraj Bommai admitting that there was a lack of town planning and unscientific methods were used for creating new residential layouts.

Bommai said on Monday that he has instructed the officials to see to it that water is drained out from the inundated roads at the earliest, as reported by PTI.

“There have been heavy rains in Bengaluru, I have spoken to the commissioner (BBMP) and other officials. I have asked officials to depute two state disaster response fund (SDRF) teams to Mahdevapura and Bommanahalli zones in the city that have been worst affected, with boats and other equipment..also engineers are there,” Bommai was quoted as saying by PTI.

“There is a plan on how to create a temporary drain and how to go about it (drain out water), it will be operationalised...”he added.

Meanwhile, urban planner V Ravichandar said unless a change in storm water drainage is brought about, the situation in the city is going to be difficult. “Our growth is unplanned and rampant. We have occupied several low-lying areas in the city and these areas don’t have a storm water drain. A re-look at the drainage system is much needed now,” he said.

Ashwin Mahesh, an urban planning expert, said that a fundamental change is needed in the idea of transporting rainwater through stormwater drains. According to him, the design of the city storm water drains is wrong. “Water moves faster in a cylindrical space than rectangular space. It is scientifically proven. Except for the TenderSure roads in Bengaluru, we have rectangular drainages. Apart from transporting we should use socking pits to absorb water locally,” he said.

On September 15, 2020, the Comptroller & Auditor General (CAG) had pulled up the agencies for inefficiency in identifying and managing storm water drains (SWDs) in the city. A performance audit report tabled in the legislative assembly on Wednesday mentioned a lack of financial discipline, shoddy mapping of SWDs and tertiary drains, lack of documents related to various works taken up, and failure to clear lake and SWD encroachments.

“There were discrepancies between the figures exhibited in the budget estimates and actual expenditure recorded in the cash book. This indicated the lack of reconciliation mechanism and correct reporting of expenditure, and exposes the financial indiscipline reigning in BBMP,” the report said.

It also added that out of the 1,988 encroachments identified by BBMP, 1,225 were declared to be removed. However, evictions were incomplete and did not improve the condition of drains.

“Bengaluru’s storm water drain network is over 850km. While it’s supposed to channel storm water during the rains and be empty the rest of the year, the reality is different, with the drains filled with sewage and garbage,” said Naresh Narasimhan, architect, and urban activist.

Meanwhile, following Bommai’s directions, the Bruhat Bengaluru Mahanagara Palike (BBMP) started clearing properties, which have encroached storm-water drains in the city. On Saturday, constructions were razed in Dodda Bommasandra as well as Varthur.

“Encroachments have to be removed immediately as they have reduced the width of our rajakaluves. We are also doing some lining and cleaning work due to which rainwater flows quickly now. In zones like Mahadevapura and Bommanahalli, previous authorities had given licences to build, but now the drains at those places are affected. Hence, we are concentrating more on clearing encroachments in Dasarahalli, Rajarajeshwarinagar, Yeshwanthpur, KR Puram, and Mahadevapura,” said BBMP chief civic commissioner Tushar Giri Nath.