Stop Chattogram’s Expansion Into Flood-Prone Areas: Climate Risk Must Be Central

By the Editorial Team · Saturday, October 24, 2026

Nearly one-quarter of Chattogram’s urban land has rapidly expanded in flood-prone coastal areas, increasing the city’s vulnerability to severe flooding and infrastructure damage. The Asian Development Bank urges stronger enforcement of building regulations and integration of flood risk into urban planning to protect residents and reduce future economic and social costs.

Nearly one-quarter of Chattogram’s urbanized land is located in areas vulnerable to severe coastal flooding, raising concerns about the city’s rapid and risky expansion in flood-prone zones. The Asian Development Bank’s (ADB) Asia-Pacific Climate Report 2026 highlights that these areas, which face significant flood risks, have experienced faster construction growth compared to safer parts of the city.

Between 2016 and 2025, Chattogram’s built-up area increased from 66.1 square kilometers to 73.5 square kilometers. During the same period, settlements in flood-prone zones expanded by 16.2 percent, outpacing the 9.7 percent growth seen in less vulnerable locations. The report warns that continued development in these zones could place residents and infrastructure at heightened risk, with floodwaters exceeding half a meter capable of damaging buildings and disrupting essential services including water supply, sanitation, and electricity. In the most exposed areas, water levels could reach more than 1.5 meters during severe coastal floods.

While the Chattogram Development Authority (CDA) has been effective in drafting development plans, enforcement remains a critical issue. The CDA’s deputy chief town planner stated that the authority’s master plan does not formally classify any parts of the city as flood-prone, although construction is prohibited in designated water retention areas. This discrepancy between actual flood risk and planning designations suggests a significant gap that could increase the city's vulnerability to flooding.

The ADB report projects that by 2100, as many as 17.5 million people could be affected annually by coastal flooding across the region. Poorer coastal communities, in particular, face disproportionate challenges, already allocating approximately 17.25 percent of their annual income toward flood protection measures. This underscores the necessity of integrating climate adaptation into broader urban planning, poverty reduction, and economic development strategies.

As Chattogram’s new master plan approaches finalization, the report calls for the incorporation of flood risk mapping, independent planning reviews, and stricter enforcement of building regulations. Recommendations include safeguarding natural drainage and water retention areas, enhancing CDA’s monitoring capabilities, and increasing accountability for regulatory violations. Additionally, developing satellite towns and upgrading infrastructure beyond the city limits could alleviate pressure on vulnerable areas.

Experts emphasize that addressing the risks now is critical to avoiding the costly consequences of unplanned urban expansion and repeated flood damage in the future.

This article was reported by synthesizing coverage from multiple independent news outlets to present a balanced, unbiased account. Read about our editorial standards. Spotted an error? Let us know.