Bengaluru may need new canals to handle heavy rains

From financial indiscipline, shoddy mapping of major drains, failing to clear encroachments to making unfruitful expenditure on sewage diversion and ‘misplacing’ documents related to various projects, the recent Comptroller and Auditor General (CAG) report on the BBMP’s stormwater drain (SWD) department exposed all that’s wrong with the system.

While the performance audit report by a premier organisation has been gathering dust with no seriousness to implement the recommendations, a large part of Bengaluru, particularly the IT corridor, has been bearing the brunt of the BBMP’s insensitive and lackadaisical attitude.

The CAG’s 2021 report found that the SWD department neither had a robust policy governing stormwater management nor prepared a manual specifying the design, construction and maintenance of SWD infrastructure of the city. “It failed to factor in reasons for high-intensity rainfall due to rapid urbanisation… Groundwater recharge structures were not taken up due to the flow of sewage in SWDs. Water bodies and drains were not inter-connected and linkage between different drains was absent,” the report states.

During the audit, records such as ‘completion plans’, ‘built drawings’ and ‘works history registers’, which are vital for subsequent planning, were absent.

The CAG also exposed the BBMP’s claim of reducing the drain encroachments to 714 from 2,626. During the joint inspection, the auditors found community halls existed on either side of the drain and were connected with a concrete platform linking the two buildings while the information furnished by the BBMP to the audit team said the encroachment was removed in August 2016.

The BBMP’s carelessness from a position of power has not only caused a huge economic loss to companies that are providing large-scale employment but the floods have destroyed the life and belongings of over 30,000 residents, including the economically-weaker section of society.

Experts hope the authorities use the adverse situation to ensure Bengaluru is flood-proof in the future. They warn the monsoon in the years to come could be much worse than what the city has witnessed in the last week. Besides clearing encroachments in the existing network, some suggested the creation of new canals in the low-lying areas to handle heavy rains.

Raj Bhagat P, senior manager at WRI India (Sustainable Cities), said the BBMP must come up with an SWD master plan for the city with state-of-the-art simulations and discharge calculations. “Based on the plan, new canals and drains need to be created particularly for the areas that have been constructed in valleys,” he said.

Bhagat also advised the authorities to publish the data on stormwater drains in the public domain. “We need to create open-access highly granular datasets on topography, flood risk and stormwater drains. Open data would help the public and experts to better understand the situation and provide insights and solutions to the government which could be cheaper and would consume lesser time,” he said.

Clement Jayakumar, a member of the Mahadevapura Task Force headed by MLA Aravind Limbavali, is of the view that the BBMP should merge the lake and SWD for better coordination. He also said the BBMP’s approach to remodelling drains from upstream has been the cause of flooding. “Drains should be developed from the downstream or the BBMP should ensure they are in a reasonably good shape to carry water in case the funds are not available,” he said.

BBMP Chief Commissioner Tushar Giri Nath said the civic body would re-verify the condition of all stormwater drains to assess their capacity to handle heavy rains. “We are also open to building an entirely new drain by acquiring properties,” he said.

Urbanist Ashwin Mahesh said the BBMP must respect the city’s topography. “There is no point blaming previous governments. What must be done is to stop the construction of new buildings on stormwater drains from now. The integrity of the drain has to be maintained. Permission should not be given regardless of who owns the property,” he said.

On the same point, Bhagat suggested land pooling schemes in developing areas so that the economic aspirations of people who own land in valleys are not affected when the land uses are restricted.