Every year, with unfailing regularity, the residential locality of HSR Layout — developed on a lake — gets inundated when a heavy spell of rain lashes the city. In an attempt to address this problem, the civic body wants to build a new water diversion channel.
HSR Layout, especially Sector 3 which is most prone to flooding, was developed on Yellukunte lake that falls between Somasundara Palya lake and Agara lake downstream. This has disrupted water flow channels in the watershed area. The drains in HSR Layout that are tasked with carrying water overflow from Somasundara Palya lake are too narrow.
“The rajakaluves have been encroached upon by the Bangalore Development Authority, and the Revenue Department has converted this land into B Kharab land, which we will take up with the agencies concerned,” said BBMP Commissioner B.H. Anil Kumar, who inspected the spot recently.
The Bruhat Bengaluru Mahanagara Palike has now decided to build a 1.24-km-long stormwater drain (SWD) from Somasundara Palya lake to Agara lake, which they hope will provide an alternate channel for flow of water and not flood HSR Layout.
Water conservationist S. Vishwanath said the drain must be designed for high intensity rainfall and a high run off coefficient as the area is now completely paved. “Given that the layout is developed on a lakebed, there is potential for recharge wells. The BBMP should consider this as well,” he said.
Mr. Kumar said that immersion pits will be integrated into the plan.
However, there seems to be some opposition to the route this drain will take. Civic officials plan to build it from the SS Palya lake to Agara lake in HSR Layout. However, residents are not convinced that this is the best plan.
“The drain must go through the 19th Main Road, but instead it is now being routed through narrow residential by-lanes,” said Zahid Javali, a resident activist.
The civic body has identified two other missing stretches of drains between Garvebavi Palya lake and Agara lake that lead to flooding of Mangammana Palya, and between Madiwala lake and Agara lake flooding Anugraha Layout. BBMP will build drains on these stretches as well.
The SWD stretch between Madiwala and Agara lakes is very narrow, and has sharp 90-degree turns that block water flow, which will be corrected now, said civic officials.
Pre-cast drains
The civic body has decided to build these drains with pre-cast material to ensure that the project is ready before the next monsoon. “I have directed that the DPR be prepared by January and tenders issued. We will deploy multiple teams, and use pre-cast elements to finish work in two months,” said Mr. Kumar.
