Bengaluru's Outer Ring Road completely inundated with only 2mm rainfall, here's why

The area surrounding Savalkere or Saul Kere in Bengaluru received just 2mm of rainfall on Sunday night. Yet, the Outer Ring Road was completely inundated.

Savalkere was filled to the brim and the overflowing water turned the Outer Ring Road into a river, resulting in waterlogging at RMZ Ecospace, the tech park located on the arterial road.

Vehicular movement along the stretch was also grindingly slow.

“The water from Savalkere overflowed and the water went into the nearby sewage drain. This sewage water is now flowing into the Outer Ring Road. The HSR Layout Police have had to literally push two wheelers to safety. They have been working since last night to ensure the safety of commuters. The water has now flooded the service road and vehicular movement is happening only on one side of the road. Pedestrians have been advised to use the skywalk,” said DCP (East) Traffic, Abhishek Goyal.

Employees of Ecospace were advised to work from home and the pick-up facility was cancelled due to severe waterlogging.

“Many employees have been coming in for work. The waterlogging has occurred only near the Ecospace gate. There has been no flooding inside the building. Ecospace security personnel and the Bengaluru Traffic Police have been helping vehicles enter and exit the area without any difficulty. Buses are also able to ply,” a spokesperson from Ecospace told TNM.

What caused a major arterial road to flood with just 2mm rain?

Spread across 62 acres, Savalkere or Saul Kere is one of the largest lakes in the area. Activists say that more than three acres of the lake were encroached upon by illegal occupants, with houses built on the lake bed.

Despite issuing notices to vacate the land, the encroachers paid no heed. In 2013, they were cleared and the restoration process of the lake was started.

“This is also done shoddily. If you see the height of the inlet and the outlet, it is uneven. Water from a lake must not overflow, the height of the inlet and outlet (which themselves are storm water drains) must be equal. In Savalkere, the height of the outlet is lower than that of the inlet. Obviously, the water will overflow. Besides, so many restaurants and houses have encroached on the interconnected system of storm water drains. The BBMP has built several concrete drains but this is not enough,” said Ramprasad, convenor of citizens’ group called Friends of Lakes.

Nagesh, a lake activist from Bellandur area, who is working for the rejuvenation of Savalkere, said that currently, there is only one tertiary sewage drain which is connected to the lake’s outlet.

“The outlet is connected to a drain which in no way is capable of withstanding the outflow from the lake. The main issue is that the storm water drain system has been encroached upon. BBMP has constructed several secondary drains but these are made of concrete and there is no scope for the water to seep into the ground. Besides, none of these storm water drains have been desilted. That’s why just 2mm rainfall has resulted in waterlogging,” Nagesh added.