19 years later, Mumbai still drowning

On July 26, 2005, Mumbai endured a catastrophic deluge, with an unprecedented 944 mm of rainfall pummeling the city in just 24 hours. The torrential downpour triggered widespread and devastating flooding, claiming over 1,000 lives and inflicting immense damage on infrastructure and property. This cataclysmic event, one of the most severe in the city's history, exposed the critical deficiencies in Mumbai's urban planning and flood management systems.

As we remember, that bleak day today 19 years ago, the ongoing 2024 monsoon season too is witnessing Mumbai once again grappling with severe flooding, disruption of transportation, closure of schools, and once again exposing the city's vulnerability to extreme rainfall. In a single day this season, Mumbai recorded over 300 mm of rainfall, leading to widespread waterlogging and significant disruptions in daily life. ​

Infrastructure improvements since 2005

Since the 2005 floods, Mumbai has made significant strides in improving its stormwater drainage system. The Brihanmumbai Municipal Corporation (BMC) has undertaken various projects, including the installation of high-capacity pumps and the expansion of stormwater drains to handle up to 50 mm of rain per hour, doubling the previous capacity​. Additionally, new pumping stations have been constructed to expedite water removal during heavy rainfall​​.

Floodgates have been introduced to control seawater ingress, a critical measure given Mumbai's coastal location. Currently, only three out of 105 outfalls are equipped with floodgates, highlighting both progress and limitations in this area​​. While these improvements have mitigated flooding to some extent, challenges remain in terms of the comprehensive implementation and maintenance of these systems​​.

Persistent challenges

Despite infrastructure improvements, Mumbai still faces persistent challenges, exacerbating flood risks. Uncontrolled urban development has significantly impacted the city's ability to manage floodwaters. Unplanned construction, particularly in the northern suburbs, has led to increased surface runoff and overwhelmed drainage systems. For instance, areas like Andheri and Goregaon frequently experience severe flooding due to inadequate planning and drainage capacity​.

Additionally, the city's infrastructure suffers from inadequate maintenance and upgrades. Many drainage projects face delays or fail to deliver expected outcomes due to insufficient funding and bureaucratic hurdles. For example, the long-proposed BRIMSTOWAD project has seen partial implementation, leaving many areas vulnerable during heavy rains​.

Climate change and its impact

Climate change has dramatically intensified the frequency and severity of extreme weather events in Mumbai, with monsoon flooding emerging as a particularly devastating consequence. A stark indicator of this trend is the threefold increase in heavy rainfall events across central India, including Mumbai, between 1901 and 2015. This alarming surge is primarily attributed to the warming Arabian Sea, which fuels moisture-laden winds that deliver intense and prolonged precipitation.

The big question - What needs to be done?

Since the devastating 2005 floods, both governmental and community efforts have been mobilised to enhance Mumbai's resilience to extreme rainfall events. The establishment of the Mumbai Disaster Management Cell has centralised disaster response and coordination. Furthermore, advancements in early warning systems, including the use of meteorological data and advanced modelling, have improved the city's ability to predict and prepare for heavy rainfall. Regular emergency drills, involving various stakeholders, have sharpened response capabilities.

On the community front, a surge of grassroots initiatives has emerged. Local residents have formed flood response teams equipped with the necessary resources to assist during emergencies. Moreover, extensive awareness campaigns have been conducted to educate the public about flood safety measures, evacuation procedures, and the importance of disaster preparedness. These community-driven efforts have significantly contributed to building a more resilient and informed citizenry.

The city needs to implement an integrated water management plan that includes the rejuvenation of natural water bodies such as wetlands and lakes, which historically acted as sponges, absorbing excess rainfall and acting as natural buffers. Additionally, the city must commit to extensive mangrove reforestation. These coastal ecosystems serve as natural barriers, dissipating wave energy and reducing flood impacts. By reviving these vital ecological systems, Mumbai can significantly enhance its resilience to extreme weather events.

Upgrading and maintaining existing drainage systems are crucial, as is ensuring strict adherence to building regulations to prevent encroachment on floodplains. Public awareness campaigns on waste management can also help prevent blockages in drainage systems. Collaborative efforts between government bodies, urban planners, and the community are essential to creating a resilient Mumbai capable of withstanding future monsoon seasons.

The 2005 Mumbai floods highlighted critical gaps in infrastructure, urban planning, and disaster management. While progress has been made, significant challenges remain. Continuous improvement in flood mitigation strategies, environmental conservation, and robust community involvement are essential to protect Mumbai from future climate-induced disasters. A collective effort is needed to build resilience and safeguard lives.