Water security is an increasingly important issue for South Africans. Drought, deteriorating infrastructure and the questionable safety of our municipal supply puts provision of this – the most essential element for life – in jeopardy.
In the Eastern Cape, a crippling drought, failing infrastructure and recent reports of high levels of cancer-causing chemical byproducts and faecal matter in the tap water has shifted residents’ concerns from simple water conservation to mitigate the looming “Day Zero” to the larger, ongoing concern of ensuring enough potable water for their households far into the future.
Though our country’s landscape is predominantly dry, with only the eastern parts receiving generous rainfall, groundwater has proven a dependable source for many living in arid and desert regions. If your property can accommodate a borehole, you’ll certainly be able to achieve partial or even complete independence from the water grid, though this – of course – is not an option for all.
Harvesting rainwater is, however, an immediate solution that is more affordable and more easily instituted. In most instances, roofs and guttering are already in place and, with a few very simple modifications, rainwater from the roof can be redirected and stored for later use.
Eco-Consulting’s Chris Davidge advises, “Though Gqeberha is in the middle of a prolonged drought, the city itself receives enough rainfall to provide for household requirements if that water is captured, stored, and made safe for consumption.”
Chris explains, “You’ll get one litre of fresh water for every one millimetre of rain that falls on each square metre of your roof. A roof of 100 m2, will gather 100 litres per 1 mm of rain and tanks fill up quickly when we have a good downpour. For instance, in the past two months, Gqeberha has been blessed with about 35 mm of rain … which works out to 3500 litres from a 100m2 roof. The question then becomes: How much water can you safely store?”
Working on an allocation of 50 litres per person per day, a full 2500-litre tank will provide a 4-person household with 12 days of water. Choosing a tank size will depend on the space you have available, your household needs, and whether your goal is to augment municipal supply or replace it completely.
Chris recommends the following to meld harvested water safely into your existing system:
1. Gutter Guards
Hardware stores stock a variety of products to prevent leaves and other materials from polluting or blocking your gutters. Simple gauze protection is the first step in successfully harvesting clean water.
2. First Flush Diverter
To prevent roof dust and dirt from contaminating your storage tank, install a first flush diverter. This device dumps the first few litres of rain that washes your roof clean. Thereafter, only debris-free water will flow into the tank.
3. Water Filtration
To ensure you don’t consume unhealthy water, stored rainwater should be filtered before use. Invest in a separate water filter that removes all parasites and bacteria to safeguard the quality of your household supply.
4. Booster Pump and Pressure Switch
Make it as convenient as possible to use your harvested water. Connect a pump that can deliver filtered water into your house or to a dedicated tap. Save electricity by adding a pressure switch to the pump to make sure it only runs when there is a drop in pressure, that is when a tap is opened.
5. Switch Over
To switch between tank and municipal water, you’ll need a change-over valve. And, if you’re pumping water into your existing plumbing, you should fit a non-return valve to the municipal water inlet to prevent your harvested water from dispersing into the grid.
It’s as easy as that to ensure a reliable flow of healthy water to your family now and into the future. Essential, life-giving rain is delivered to us completely free of charge! All we need to do is ensure we’re making the best use of this gift.