In trying to make sense of the current flooding in Kwazulu-Natal, it is immediately obvious that we cannot afford to continue with a 'living in a bubble' mindset. Yes, flooding has occurred before and we rose from the devastation. Yes,infrastructure is ageing, maintenance has not been kept up by municipalities and yes, the volumes of water were unpredictable . . . but there is a far greater problem here.
The truth is that much of what has happened to those living in areas on lower ground is due to mismanagement and a lack of understanding about the power of water, from those living on higher ground.
If you look at the damage, it has resulted from water accumulating on higher ground - often hundreds of kilometres away and taking the line of least resistance as it finds its way to lower ground. On a smaller scale, it could just be water from a neighbouring property or from the top of the street (as happened to my client).
I certainly don't have all the answers but what I know is that those who live on higher ground - residential, commercial and especially current developments, have a moral obligation to monitor the movement of water from their properties when it is raining and track its direction and progress. We also need to check retaining structures to ensure that they are erected properly, allowing water to drain away slowly and safely without exerting undue pressure on the structure, causing collapse and resulting in a mudslide of varying volumes.
What can we do to ensure that this doesn't happen again?
There is no one solution to what has happened but I will say that every homeowner needs to do an immediate audit of their property to see what, if anything, went wrong this time around or what could potentially go wrong in the future. Here are a few things you can check:
1. Ensure that your or your neighbour's boundary walls/structures have regularly spaced
drainage holes that will allow water to seep through and not dam up behind the structure.
Slow but steady seepage will not result in the same devastating damage as full-force water
causing an entire boundary wall to collapse. (Case study - in my road, someone has dug a
single hole under their wall and the water exiting the property is flowing so fast that it has
gouged a channel out of the verge and is spilled in a strong stream across the road which
can be dangerous for traffic. The neighbour across the way has no weep holes in his wall
and it is about to collapse);
2. If you live at the top of a road, gauge the camber of the road, monitor how the water flows
off the road, where it might enter your property and whether it can be diverted away from all
houses and hopefully to a drain nearby;
3. If you have recurring water issues on your land, find out from your municipality where the
storm water drainage is situated. It could be leaking, damaged or simply unable to cope with
volumes of water. After this fiasco, your municipality will have no option but to fix it;
4. Ensure that all bare land is covered with either a fabric such as Soilsaver from Kaytech in
Pinetown, a biodegradable jute fabric that you can plant into, or plant it up thickly with
groundcovers, lawn or anything else that will slow the movement of water.
5. Developers should pay special attention to vacant sites on higher ground, especially when
heavy rain is predicted. I am not an engineer so I don't know exactly what to suggest, but
they must take action. Again, Kaytech has a number of products to alleviate this problem.
(Please note that I have no shares in the company!) A major distaster occurred in
Amanzimtoti some years ago where water rushed across a vacant building site and took out
a home below, and now again in Umdloti where soil from a bare piece of land has (see behind
the blue house) wiped out homes and apartment blocks below and the chasm will most
likely remain a scar on the earth forever.
(Photo received from a friend whose in-laws live in the house on the left of the blue
house)
6. If you have unprecedented water rising from the ground, check to see whether your home is
built on a vlei (wetland) which remains dry for most of the year until heavy rains occur and
then it is suddenly swamped by rising water. An engineer will be able to advise you on
how to treat this problem. (Case study : I have a student in north-west province who
experienced this flooding recently. She has since discovered that their home was built on
reclaimed vlei (wetland) and, an added complication, they also receive all the run-off from
their neighbour.)
Practical solutions
There is no one-solution-fits-all for this problem. I hope though that this conversation will cause you to think, take stock and, above all else, observe and take preventative action for the future.
So what can one do?
Retaining structures : As mentioned earlier, ensure that all retention on your property has drainage holes, a lining of a permeable fabric such as bidim or Weedguard behind the retaining material, and is back-filled with stones, building rubble - anything that will slow the water but allow it to drain, irrespective of the material you are using. I have seem timber, rock and retaining blocks collapse in these floods. We just have to do as much as we possibly can to minimise damage.
SoilSaver® is made from a biodegradable 100% jute yarn woven to form a 65% open mesh structure which is ideal for erosion control. The open structure of the material provides space for plant propagation and growth.
Read up on the benefits of creating berms if you live on sloping land as these 'channels' will
catch the water and redirect it into the soil, instead of allowing it to flow steadily downhill. In
my client's garden where a bank has washed away from the water coming off the
neighbour's driveway, their back garden which is even steeper has suffered no damage
because we introduced berms across the full width of the property and planted it up with
water loving plants. (You cannot see the full extent of how deep that berm is because we had just mulched it, but the grass has managed to establish itself below that berm now instead of always washing away in heavy rains.)
Plant slopes with a thick groundcover (Plectranthus, loads of Agapanthus, Clivia or Tulbaghia (wild garlic), the normal mondo grass (Ophiopogon japonicus) or lawn. This again will slow the movement of the water. We know that you cannot stop water, but both the roots and foliage of these plants will assist to prevent severe damage.
Reduce the amount of hard surfaces around your home, and this I cannot stress enough. We have courtyards, patios, driveways - all of them constructed from non-absorptive materials and the perfect scenario for water to hit and pick up speed. That water will either return into the home if it cannot find an escape route or it will find a weak spot, go underground and cause washaways. If you are going for the hard surface look then you need plenty drainage that won't flow into a neighbouring property, so consult your plumber/builder/architect about french drains and soakaway pits. Decking, underplanted with a shade-loving groundcover, is more expensive but will save you the heartache in the long term.
Where necessary, plant lawn above your slopes and don't let anyone tell you that lawn is sterile, high maintenance, blah blah . . . It is a lifesaver! It is absorptive, it's a carbon sink, there is plenty of life in and under lawn, and it has hundreds of other positives. Yes there is a downside to lawn when it is not balanced with planting for wildlife but that is a different matter. And no, you do not need to water your lawn or ply it with fertiliser every 5 minutes. I never feed or water my lawn, but I cut it correctly and it is lush and healthy. I have removed all the bricks around my pool and replaced it up to the coping with lawn and what a pleasure. My house is cooler, it is nicer underfoot . . . and it is absorptive.
Plant Vetiver grass to hold banks. Vetiver is not indigenous but neither is it invasive. It has a root system of up to three metres (non-aggressive and not a butress root system) but it acts as a great soil-stabiliser as well as having many health and socio-economic benefits. Do some research. They used it initially on sugar cane farms in the early days to trap soil that was blowing across the land. Another plant you can mass to minimise water damage is Juncus kraussii, a lower- growing, water-loving plant with good clumping roots. It saved my client's garden from disappearing completely when the water flooded in from the neighbouring property.
In conclusion, I think I have illustrated the point that we each need to have take control of the water situation on our own property, with co-operation from neighbours, municipal authorities, etc.
We do not live in a bubble and every single thing we do on our land affects someone else down the line. (Don't even get me started on bad tree choices!)