YONELA DIKO: Flooding is part of our lives now, and we must be prepared
Last week the Western Cape experienced its annual heavy rainfall, which saw whole neighbourhoods’ knee-deep in water, massive destruction to housing, and disruptions to livelihoods. As would be expected, much of the destruction was in informal settlements, where there are many make-shift structures that characterise a large part of our landscape. But even in neighbourhoods with more resilient built environments, there were clearly glaring inadequacies in ensuring that water does not accumulate and engulf homes when heavy rains pour.
In the last 12 months similar heavy rainfall happened, accompanied by storms and landfalls, in cities like Johannesburg and Durban with equally devastating and destructive results. Again, the most affected areas were informal settlements, especially those built close to the river banks, which tend to break with heavy rain. In Gauteng, it affected areas such as Centurion and Midrand, causing great destruction.
These floods are recurring annually and are becoming more violent and destructive. It's important we accept that heavy rains and flooding are here to stay, so our aim must be to build flood resilient human settlements and communities.
There are many flood defence mechanisms we can put in place to have durable built environments. Many of these measures can be applied when we are building structures, particularly in new communities, and several can be used to complement old areas that continue to experience occasional floods and landfalls.
As part of building full-service communities, we have to think beyond the usual basic needs compact of water, sanitation, electricity, roads etc and start thinking about contingencies. As part of our built environment, we should always consider constructing wetlands around our communities. Wetlands are one of the greatest ways to protect homes and houses from flooding. They are able to absorb huge amounts of water, ensuring that only a little water, if any at all, passes through. Wetlands are not only useful in mitigating floods but are also good for plant life and to protect the environment from the effects of climate change.
It has been proven that areas that are more wooden and have more trees also serve to slow down water when it flows from rains. This means when we remove all the trees and destroy forests to make way for development, we are also pulling down the one great defence mechanism that is supposed to protect those very communities from heavy rains and flooding.
The World Wildlife Foundation says: "Halting deforestation and wetland drainage, reforesting upstream areas and restoring damaged wetlands could significantly reduce the impact of climate change on flooding."
It has been pointed out that during our journey of progress humankind has had to occasionally opened up and straighten our rivers and pathways, mostly for navigation and transportation. This has also made it easy for the flow of heavy streams to flood because a "meandering river channel slows down the flooding of water downstream". This effectively means nature in its original state had built-in mechanisms to ensure a perfect balance, but our industrialisation, development, harvesting and reconstruction for our endless needs have tampered with that balance, and we are now occasionally victims of our own decisions to fiddle with nature.
We can recreate the meandering nature of rivers that was always supposed to be part of the defence mechanisms against flooding. We can also attempt to create new meandering flows to those open rivers that spill water into communities when river banks break.
I has also been proven that building culverts underneath the roads in areas prone to floods is a critical intervention. This gives water clear pathways toward targeted catchments where water can be stored and preserved. Culverts are those open structures under roads and trails that allow water to flow underneath.
We have to build enough culverts that can ensure water does not become stationary but is led into either the wetlands, meandering rivers or any of our other water catchment areas. Culverts have been proven to reduce flooding dramatically.
Home soil care, raised embarkments
It is also important that we take good care of our soil around our homes so that it does not become too compact to absorb and hold water instead of just running off as soon as it lands. This means soil's ability to absorb a lot of water can also become another flood defence mechanism. We must keep our soil dry and well drained so that it can absorb huge quantities of water.
For those areas that flood year in and year out, it is also important that they invest in temporary barriers to flooding. This may include raised embarkments. It would be ideal if these raised embarkments self-activated when water began to rise. Some of these temporary flood barriers are sold at the warehouse down the street and it may well be that every household and or community should invest in them.
There are the basic tenets that we must always adhere to, to avoid our homes being flooded. These include ensuring our drainage is in good working order, placing sandbags in strategic areas and listening to weather warnings in time in order to activate all your flood defences.
We need to waterproof the neighbourhoods we build, fully in the knowledge that floods will come. We must always be prepared when they do. South Africa is not the only country that experiences devastating floods every so often and we can learn from other countries how to build flood resilient communities. Britain, for example, recommends building structures that are one metre from the ground to give homes high ground.
Most structures today, particularly newly built apartment buildings, are two to three meters off the ground, with the ground floor used as parking space. Most of the new structures for social housing built by the Human Settlements Department have followed this pattern, although not always. Once you are a meter above ground you can then focus on having more robust material for building your floors, walls and roof. This also goes for how we protect our electrical wiring and sockets from being engulfed by water by placing it in strategic areas in our homes, ideally also very high up from the ground.
Both government and private construction have to invest enough money in flood defences in the structures they build. Unfortunately, in most areas in South Africa, particularly the City of Cape Town, there seems to be more investment in post-flood responses than in defence progress. The City tends to invest a lot of money in disaster management for floods or fire programmes, but seems less committed to spending on flood defences.
We know the rains are coming, we know they will flood certain areas, and we have a moral obligation to invest in defence mechanisms and preventative measures.
Yonela Diko is spokesperson for the Ministery of Human Settlements, Water and Sanitation. He writes in his personal capacity. You can follow him on Twitter @yonela_diko