Bengaluru’s Flood Risk Grows: Urgent Need for Infrastructure Upgrades
WATER & WASTE

Bengaluru’s Flood Risk Grows: Urgent Need for Infrastructure Upgrades

Bengaluru, one of India’s fastest-growing cities, has witnessed an average economic growth rate of 8.5 per cent over the past decade. As a major economic hub, it hosts diverse sectors such as technology, banking, consulting, defence, and R&D. However, this rapid development has led to large-scale urbanisation and a significant population influx, severely straining the city's natural ecosystem—especially its drainage infrastructure—leading to recurring urban flooding. 

Bengaluru’s primary stormwater channels, known as Rajakaluves, were originally built to manage stormwater by connecting to the city's lakes. Over time, unplanned development has left many of these drains are outdated or damaged. According to the Central Public Health and Environmental Engineering Organisation (CPHEEO) Manual on Sewerage and Sewerage Treatment, urban stormwater drains in Indian cities are designed for rainfall intensities of just 12–20 mm per hour. However, rainfall events in Bengaluru have significantly intensified. For instance, on 18th May 2025, the city experienced rainfall of 100–135 mm in a single day, far exceeding the system’s design capacity. 

As Bengaluru continues to expand, sustainable urban growth demands robust upgrades to critical infrastructure—particularly stormwater drainage—to prevent escalating social and economic costs.  

One of the biggest hurdles in improving the city’s drainage system is the lack of accurate and comprehensive mapping. This limits the ability of municipal authorities to assess and plan for infrastructure upgrades. Consequently, real estate projects are often approved within drainage buffer zones, further restricting water flow and exacerbating flooding. 

To address this, innovative approaches to stormwater infrastructure are essential. Global examples show that well-designed systems can yield not just environmental but also economic and social benefits. 

Japan’s “Underground Temple”, officially the Metropolitan Area Outer Underground Discharge Channel, completed in 2006, lies 50 meters below Kasukabe City. This anti-flood network consists of five massive silos linked by 6.4 km of tunnels, capturing stormwater during heavy rains and typhoons before discharging it into a nearby river. It also serves as a tourism site, with guided tours generating revenue that helps offset maintenance costs. 

Similarly, Seoul’s Cheonggyecheon Stream Restoration Project, launched in 2003, stands as a benchmark for integrated urban renewal. The initiative involved removing an elevated highway to restore a historic stream, resulting in a 639% increase in biodiversity by 2008 and a reduction in urban heat island effect by 3.3°C to 5.9°C. The upgraded flood protection system can now manage up to 118 mm/hour of rainfall, equivalent to a 200-year flood event. The revitalization significantly boosted the local economy in the form of increase in property values, tourism, public transit usage etc (Source: Landscape Architecture Foundation). 

Another forward-thinking approach is the “sponge city” model, prominent in Chinese cities like Shanghai and Wuhan. It combines traditional drainage with green solutions—rain gardens, permeable pavements, wetlands—to absorb rainwater and recharge groundwater. Backed by national policies and funding, this model addresses flooding, water scarcity, and ecological degradation. 

Bengaluru must adopt similar strategies. According to a 2023 Knight Frank report on Urban Flooding in Bengaluru, the city currently has 842 km of primary and secondary drains but needs an additional 658 km. Revamping the existing network—through desilting, dredging, and unclogging—will also be necessary. The total cost for expansion and repair is estimated at Rs 28 billion. 

Funding can be sourced from multilateral agencies like the World Bank and Asian Development Bank (ADB). For long-term maintenance, Value Capture Financing (VCF) can help ULBs recover costs through increased land values and real estate development in protected zones. 

Bengaluru’s ability to tackle its flooding crisis will depend on how quickly and effectively it can upgrade its stormwater systems—while learning from global best practices to build a more resilient urban future.

Bengaluru, one of India’s fastest-growing cities, has witnessed an average economic growth rate of 8.5 per cent over the past decade. As a major economic hub, it hosts diverse sectors such as technology, banking, consulting, defence, and R&D. However, this rapid development has led to large-scale urbanisation and a significant population influx, severely straining the city's natural ecosystem—especially its drainage infrastructure—leading to recurring urban flooding. Bengaluru’s primary stormwater channels, known as Rajakaluves, were originally built to manage stormwater by connecting to the city's lakes. Over time, unplanned development has left many of these drains are outdated or damaged. According to the Central Public Health and Environmental Engineering Organisation (CPHEEO) Manual on Sewerage and Sewerage Treatment, urban stormwater drains in Indian cities are designed for rainfall intensities of just 12–20 mm per hour. However, rainfall events in Bengaluru have significantly intensified. For instance, on 18th May 2025, the city experienced rainfall of 100–135 mm in a single day, far exceeding the system’s design capacity. As Bengaluru continues to expand, sustainable urban growth demands robust upgrades to critical infrastructure—particularly stormwater drainage—to prevent escalating social and economic costs.  One of the biggest hurdles in improving the city’s drainage system is the lack of accurate and comprehensive mapping. This limits the ability of municipal authorities to assess and plan for infrastructure upgrades. Consequently, real estate projects are often approved within drainage buffer zones, further restricting water flow and exacerbating flooding. To address this, innovative approaches to stormwater infrastructure are essential. Global examples show that well-designed systems can yield not just environmental but also economic and social benefits. Japan’s “Underground Temple”, officially the Metropolitan Area Outer Underground Discharge Channel, completed in 2006, lies 50 meters below Kasukabe City. This anti-flood network consists of five massive silos linked by 6.4 km of tunnels, capturing stormwater during heavy rains and typhoons before discharging it into a nearby river. It also serves as a tourism site, with guided tours generating revenue that helps offset maintenance costs. Similarly, Seoul’s Cheonggyecheon Stream Restoration Project, launched in 2003, stands as a benchmark for integrated urban renewal. The initiative involved removing an elevated highway to restore a historic stream, resulting in a 639% increase in biodiversity by 2008 and a reduction in urban heat island effect by 3.3°C to 5.9°C. The upgraded flood protection system can now manage up to 118 mm/hour of rainfall, equivalent to a 200-year flood event. The revitalization significantly boosted the local economy in the form of increase in property values, tourism, public transit usage etc (Source: Landscape Architecture Foundation). Another forward-thinking approach is the “sponge city” model, prominent in Chinese cities like Shanghai and Wuhan. It combines traditional drainage with green solutions—rain gardens, permeable pavements, wetlands—to absorb rainwater and recharge groundwater. Backed by national policies and funding, this model addresses flooding, water scarcity, and ecological degradation. Bengaluru must adopt similar strategies. According to a 2023 Knight Frank report on Urban Flooding in Bengaluru, the city currently has 842 km of primary and secondary drains but needs an additional 658 km. Revamping the existing network—through desilting, dredging, and unclogging—will also be necessary. The total cost for expansion and repair is estimated at Rs 28 billion. Funding can be sourced from multilateral agencies like the World Bank and Asian Development Bank (ADB). For long-term maintenance, Value Capture Financing (VCF) can help ULBs recover costs through increased land values and real estate development in protected zones. Bengaluru’s ability to tackle its flooding crisis will depend on how quickly and effectively it can upgrade its stormwater systems—while learning from global best practices to build a more resilient urban future.

Next Story
Infrastructure Urban

Jyoti Structures FY26 profit rises 56.5%

Jyoti Structures (JSL) recently reported strong financial results for the quarter and year ended 31 March 2026, driven by disciplined execution, cost management and steady progress across its order book.For Q4 FY2025-26, total income rose 44.2 per cent to Rs 2.41 billion from Rs 1.67 billion in Q4 FY2024-25. EBITDA increased 58.6 per cent to Rs 237 million, while EBITDA margin improved by 89 basis points to 9.84 per cent. Profit before tax grew 53.3 per cent to Rs 188.5 million, and net profit rose 51.9 per cent to Rs 181.4 million.For FY2025-26, total income grew 53.1 per cent to Rs 7.72 bill..

Next Story
Infrastructure Energy

Cat BEPU to Power Doppstadt Separator at IFAT 2026

Caterpillar’s Cat Battery Electric Power Unit (BEPU) has been selected by Doppstadt to power its SWS 6 Spiral Shaft Separator, which will be showcased for the first time at IFAT 2026 in Munich, Germany, from 4–7 May.The compact plug-and-play BEPU is designed to replace a diesel engine within the same space, using the same mounting locations and relative machine position. It integrates the battery, motor, inverter, onboard charging, cooling and controls, enabling OEMs to electrify existing chassis platforms without extensive redesign.Caterpillar and Cat dealer Zeppelin Power Systems have be..

Next Story
Infrastructure Urban

VECV sales rise 6.9% in April 2026

VE Commercial Vehicles, a joint venture between Volvo Group and Eicher Motors, recorded sales of 7,318 units in April 2026, compared to 6,846 units in April 2025, registering 6.9 per cent growth. The total included 7,159 units under the Eicher brand and 159 units under the Volvo brand.Eicher branded trucks and buses reported sales of 7,159 units during the month, up 6.6 per cent from 6,717 units in April 2025. In the domestic commercial vehicle market, Eicher sales rose 8.6 per cent to 6,797 units from 6,257 units a year earlier.Exports declined 21.3 per cent, with VECV recording 362 units in ..

Advertisement

Subscribe to Our Newsletter

Get daily newsletters around different themes from Construction world.

STAY CONNECTED

Advertisement

Advertisement

Advertisement