Can South Africa build flood resilience in Durban?

Rising sea levels caused by climate change are fast becoming one of the biggest threats to our homes and communities. Catastrophic floods like those experienced in Durban last month are increasingly common all over the world.

In the first six weeks of this year alone, three tropical cyclones and two tropical storms hit southeast Africa, and scientists from the World Weather Attribution (WWA) network have issued stark warnings that heavy rains, especially along Africa’s southeastern coastline, are likely to become heavier and more frequent in the years to come.

The floods in Durban are likely to be a turning point for everyone, especially after President Cyril Ramaphosa’s promise to take measures to deal with climate change. So, what are the options for property developers wanting to better equip themselves against future calamities?

Financial assistance in the short term

Residents, business owners and specialists in the property sector in Durban were not fully prepared for last month’s large-scale and forceful flooding and so, for now, the immediate recourse for all affected is financial.

So far, the government has allocated R67 million for flood relief, but throwing money retrospectively at the problem is unlikely to fix things in the long term or prevent such floods from occurring in the future. For that, government and the industry need to think of creative materials and building designs that reduce flood risks and adapt to climate change.

You don’t need to look far to get some ideas. A popular technique used in flood-risk areas of Australia, Southeast Asia and Brazil is to build homes on stilts, above ground level. It’s proved successful for now, but it is already proving harder to predict the water levels, especially as rains become more forceful.

In Boston, America, city planners are taking matters into their own hands, asking developers who are keen to build in the Marine Industrial Park to help fund a sea wall. The local authority, much like in Durban, is aware of the city’s flood risk, and the colossal costs of managing it, and so feels that developers wanting to build there should invest in the area’s future resilience.

In other parts of the world, flood reduction is prescribed into law. In Canada, for example, the local authority amended the Vancouver Building By-law, raising the flood construction level of new buildings and reinforcing setbacks from the shoreline for properties in designated flood plains, while in some parts of the UK, developers must seek permission from a local authority to build new houses, and a flood barrier must be part of their plans.

The UK has also enjoyed some successes with its Community Infrastructure Levy (CIL), which is a charge levied by local authorities on new development that doesn’t contribute to things like flood defences.

Some of the most inventive solutions come from Europe. Dutch architects have just designed an amphibious house that can float safely in the event of flooding. It works because the base is made from buoyant, air-filled concrete as opposed to the conventional foundations that anchor houses to the ground.

Can these solutions work in South Africa?

Any of these ideas could work in South Africa, but their success relies on whether property developers are included in the conversation from the start and whether developers want to be a part of the solution.

In the end, everything comes down to price. Flood-reducing materials and technologies are a great investment, but they still cost lots of money. The Dutch amphibious houses, for example, cost about 20% more to build than a normal home.

Working out who pays for this is usually the biggest sticking point. Until then, South Africa and Africa as a whole are likely to experience many more devastating floods.