Property consultancy firm Knight Frank has recommended an additional length of more than 600 kilometres of stormwater drain (SWD) to be constructed in Bengaluru, to prevent flooding.
The report titled ‘Bengaluru Urban Flood’ stated that a capital expenditure to construct, rejuvenate and rehabilitate the city's stormwater drain infrastructure is estimated to be US$350 million. "In line with our estimates, the Karnataka government in its FY2023-24 budget announced an allocation of US$375 million for developing stormwater infrastructure in the city, with assistance from the world bank," the report said.
"Bengaluru is one of the key engines of the country's economic growth, real estate development will continue to expand to accommodate the city's growth," the report added.
The company stressed that there should be a greater emphasis on the cohesive development of real estate and the strengthening of infrastructure without damaging the ecosystem in the long term. The report highlighted, "Currently, Bengaluru has 842 km of primary and secondary drains. To complement the spatial expansion, the city broadly requires an addition of approximately 658 km of primary and secondary drains adding up to a total length of 1,500 km."
The company noted that the interconnection between water bodies, including lakes and ponds, and stormwater drains have been impacted by recurrent floods due to heavy rainfall. According to the report a reduction in stormwater drain lengths is evident in the Vrishabbhavathi Valley and Koramangala Valley regions of the city.
To prevent urban flooding it is recommended that the city adopt natural solutions such as sponge city, which it described as a "new urban construction model for flood management being implemented in China, aimed at strengthening ecological infrastructure and drainage systems."