Risk-informed urban planning vital to mitigate effect of devastating floods

Authorities failing to maintain polluted drainage systems

The devastation caused by the recent floods in KwaZuluNatal, demonstrates again that the country is not moving fast enough to adopt appropriate urban planning. It should be integrating risk assessment and management in the design and development of cities.

I recently edited a book on inclusive cities in which I write about the way SA has dealt with natural disasters. There is a lack of riskinformed urban planning. This aims to create resilient cities that can withstand and adapt to natural disasters, climate change and social vulnerabilities.

In the devastation caused by recent floods, more than 45 people have died in the last two months; more than 250 homes have been severely damaged. Severe flooding and landslides caused the deaths of at least 459 people in April 2022. These floods displaced over 40,000 people, destroyed over 12,000 houses and left 45,000 people temporarily unemployed.

The cost of infrastructure and business losses amounted to about $2bn. It was one of the worst flooding events in KZN’s recorded history and eThekwini (Durban) was the worst affected city in the province.

Studies and scientific evidence have pointed to one significant factor contributing to the occurrence of severe flooding: climate change, and 2023 was the hottest year ever recorded.

The concentration of carbon emissions in the atmosphere has resulted in drastic shifts in weather patterns.

In KZN, the failure to practise risk-informed urban planning has left roads and buildings, often poorly designed, crumbling. The authorities have failed to maintain drainage systems. They have not put in place flood control measures, such as river channelisation where rivers are dredged, widened and deepened to improve flow capacity.

Flood retention basins, designed to temporarily store excess water, would also reduce downstream flooding.

Inadequate waste collection and inappropriate disposal of garbage also blocks the drains, worsening the impact of heavy rainfall. Poor drainage systems are clogged with plastic pollution. Robust waste management systems are needed to ensure water flows properly.

In some cases, inappropriate land use and unchecked expansion of urban areas into flood-prone zones have resulted in increased vulnerability to extreme weather. Strong enforcement of land use policies that restrict development in highrisk areas is essential. Municipalities such as the disaster-hit city of eThekwini in KZN must not allow people to build in floodprone areas, because once people settle in an area it becomes expensive to relocate them.

KZN urgently needs a comprehensive approach, one that involves the local community in decisionmaking around urban planning and climate change mitigation. An inclusive approach would recognise local knowledge and encourage innovative solutions suitable for the area.

Prioritising mixed-use development, density and the preservation of green spaces in city zoning and land-use regulations is essential. Urban sprawl must be curbed. The government must establish compact, walkable neighbourhoods that are not constructed on floodplains, coastal zones, or low-lying areas.

Water-sensitive urban design must be encouraged as soon as possible. This includes green roofs and permeable pavements.

More parks, urban forests and other green spaces must be established in cities and towns. They serve as carbon sinks: places that store carbon dioxide, and acting as natural reservoirs. Wetlands, riparian zones and forests must be preserved because they can act as natural buffers against flooding.

Developing an efficient network of stormwater drains, sewers and retention ponds to control the flow of water during heavy rainfall events is vital. This infrastructure should be regularly maintained and updated.

Public awareness and education campaigns on the importance of flood-resistant measures will foster a sense of responsibility in preventing flooding. Conversation

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