Across Asia and Africa in 2025, authorities are once again confronting a familiar problem: unauthorized construction on riverbeds, floodplains, and drainage corridors often identified after floods have already caused damage.
In Vadodara, India, officials recently began clearing debris and illegal structures from the Vishwamitri River floodplain. The action follows flood risk mapping conducted after the 2024 monsoon, where encroachments were blamed for worsening flood impacts. New floodplain maps are now being used to guide enforcement, highlighting how years of unregulated building narrowed the river’s natural flow area.
In Lahore, Pakistan, an official report found that housing schemes built along the Ravi River in flood prone zones suffered heavy losses during recent floods. Regulations intended to restrict development in these areas existed, but enforcement was weak, allowing construction to proceed despite known risks.
Similar concerns persist in the Delhi region, where urban planners warn that encroachments on natural drains and Delhi floodplains are increasing flood vulnerability. Illegal occupation of water channels has reduced drainage capacity, making even moderate rainfall events more disruptive.
In Kampala, Uganda, a city report linked deadly floods in October 2025 to illegal construction over major drainage channels, including the Nakivubo and Jugula channels. Authorities warned that continued violations could lead to catastrophic consequences if standards are not enforced.
Elsewhere, the pattern repeats. Flood surges in the Rawalpindi Islamabad region exposed blocked channels caused by encroachments, prompting emergency removal efforts. In Noida, India, authorities issued notices to remove farmhouses illegally built on the Yamuna floodplain and Hindon floodplains. In KwaZulu-Natal, South Africa, leaders renewed calls to strictly enforce laws against building near rivers after flash floods. In Lagos, Nigeria, officials publicly linked recent flooding to illegal construction on floodplains and blocked drains.
Taken together, these cases show that unauthorized construction on protected land is not a historical issue it remains an active contributor to flood risk today. Engineering assessments, zoning rules, and hydrological studies consistently warn against such development. When those warnings are ignored, the consequences are paid later, often by residents rather than builders or planners.
Floods may trigger the disaster, but the damage is frequently engineered years in advance.
I agree 1000%
If you can don’t construction in a 500 year flood plain!!!
But for some locations with little to no flood data it can be hard to quantify. Not all locations have I-D-F curves!
sometimes not even consistent rainfall records that makes precise return period labels like “500 year floodplain” more uncertain. But uncertainty should argue for more caution, not less. When data is thin, the safest assumption is wider buffers preserved floodways, and flexible land use not permanent structures.
But some infrastructure needs to be permanent like a hospital or a school.
True but that actually strengthens the argument for being more selective about location not more relaxed about risk.
Hospitals, schools, power substations, and water plants should be the last things placed in uncertain or poorly mapped flood zones. When data is weak permanence raises the cost of being wrong.