Plastic, debris choking city’s arterial drains

BENGALURU: If encroachment of stormwater drains is a major reason for flooding, another reason is polythene bags and garbage that cause major blockages by hindering the flow of water, say experts.
In Bruhat Bangalore Mahanagara Palike (BBMP) limits, there are 633 storm water drains which run a length of 842 km. Of this, 142 km are primary drains and 426 km are secondary drains. The drains are built to handle 80 mm of rainfall, but over the years, encroachments and poor maintenance have narrowed the capacity to just 35-40 mm of rainfall. Rainfall above this figure results in flooding.

In July 2016, BBMP officials had given a list of 1,953 SWD encroachments to the then Chief Minister Siddaramaiah. Of these, they had cleared 1,255 encroachments by 2017.  Even today, the number remains almost the same.

Urban expert V Ravichandar told TNIE that there were many reasons for flooding of storm water drains. The holding capacity of lakes as well as drains has come down in the city due to encroachment. Added to this, polythene bags, garbage and even debris in drains has reduced the capacity to half. This also means, the remaining water, which otherwise could have flown in drains, will naturally overflow, causing floods, he said.

At many places, the BBMP authorities were seen constructing concrete drains. Ravichandar said this was a bad idea. “Rainwater that falls on the ground has to enter underground so that the underground water is recharged. If water flows slowly into the drains through porous ground, water table can recharge. But concrete drains will make water flow faster and ground water can’t be recharged,’’ he added.
Srinivasa Allur, president of SLN Residency Apartment Welfare Association, said people tend to throw waste into the drains, especially during night.

‘Axe to fall on encroachers’

Bengaluru: Chief Minister H D Kumaraswamy on Tuesday warned that action would be take against those who have illegally encroached on storm water drains across the city. Responding to queries from newspersons at his home-office Krishna on Tuesday morning, Kumaraswamy said: “Anybody who is encroaching illegally will be acted upon, whether rich or poor. I am holding a meeting with top officials on September 28 to proceed about it in a planned manner.” Some houses have come up on drains, the CM explained. "If we act immediately, many will become homeless. This problem is not because of our government but has existed for the last 40 years," he added.  To a query on the same areas which suffered from waterlogging during last year rains suffering again, the CM said, "I have asked the Chief Secretary to convene a meeting and gather all details of the previous year and the steps taken in this connection.”