Greywater systems to save gardens (and property values) during dry summers

© Thanasak Kusolvisitkul – 123RF.com

“One of the areas in the home that takes a vast amount of water to maintain is the garden. In fact, statistically South African homeowners consume between 30% and 50% of their household water usage on maintaining their gardens, the reason that watering gardens with municipal drinking water is currently prohibited in the Western Cape,” says Goslett. “Homeowners with established gardens they want to maintain during restriction periods will need to find alternate watering methods, such as using water that would normally flow down the drain.”

Grey water is waste water from baths, showers, sinks, and appliances such as the washing machine or dishwasher. It does not include water from either the toilet system or kitchen water, as the fat content can be harmful to plants. With the average daily water consumption per person around 100 litres, a family of four could use as much as 144,000 litres every year, most of which will end up down the drain. That is a vast amount of water that could be redirected and used to maintain a garden.

“While some people might be worried that the soaps in the water could have a negative effect on their plants, experts from Grey Water Systems in Cape Town say that the residues and soaps in their diluted quantities actually provide useful sulphates and nitrates that are more beneficial than using water straight from the tap. That said, they say it is advisable to use biodegradable products in your washing machine,” says Goslett.

Bacteria is another concern that some people have with using grey water; however, if the water is used within 24 hours there is no need for concern at all. Using it within a day will also ensure that it smells good when you use it. Another way to minimise possible odours is by directing the water as close to plant’s roots as possible.

The size of the garden and watering requirements will determine the type of greywater system that the household requires to maintain the garden effectively. Ideally, the system should allow water to run back into the sewer system if required - this would be necessary during periods of high rainfall or when chemicals are added to the water.

For small gardens, a tankless water diversion system would be the best option, such as the G-Flow system from Water Conservation Systems, which uses waste water as it flows through the drain. This is the ideal system for sectional title properties or homes with space constraints. More involved systems are available for larger homes with irrigation systems where the greywater is channelled into a tank or a filter. The filter is imperative if the water is going to be used on fruits and vegetables or any other edible plants. Once collected, the water can then be pumped through the irrigation system to water the garden. The pump will require a waterproof exterior electrical connection, but tankless or not, both systems can be connected to the existing plumbing and are simple to install, provided the plumbing outlets are easily accessible. Companies such as Grey Water Systems and Water Conservation Systems provide DIY kits with detailed installation manuals, alternately there is the option of hiring a reputable plumber to get the job done.

“A greywater system can eliminate the need to use tap water in the garden, which will save water and costs while adding appeal to your property,” Goslett concludes.