Drought solutions

Jan 22, 2018 | Advice

Thomas JD Murphy explains what your clients should know about residential water-saving systems

The water crisis has had a severe impact on parts of South Africa, particularly the Western Cape. Restrictions and significant predicted tariff increases have made water-saving systems in residential homes no longer a choice, but a necessity. It pays to be up to speed with current regulations and cost estimates of making those types of changes to a property. Whether it’s a new build or renovation, these systems can improve lifestyle and add value to any property.


A residential building is typically supplied with municipal water and produces “black” (toilet) and “grey” (bath/shower, basin, washing machine and dishwasher) waste water. The national water law allows for the point of use (on your property) recycling of grey water for toilet and irrigation uses only. A property owner is also allowed to collect, store and treat rain, borehole, well, river and most other freshwater sources for potable reuse. Point of use black water treatment is prohibited, as is point of use black and grey water treatment for potable reuse. However, this is likely to change.


Homeowners can redirect gutters to rainwater storage tanks above or below ground, depending on budget and preferences. Typical installation costs range from R5,000 for a 1,000l aboveground tank for a small townhouse to R140,000 for 30,000l of underground storage capacity for a large property. Potable treatment systems, starting at about R15,000, allow treated rainwater to be pumped into residential mains or plumbed to a specific appliance.


Homeowners are allowed to plumb grey water sources to a 150l surge tank with basic filtration and pump it to toilets or a garden. Basic systems range from R10,000 to R40,000 installed. This water is reused only once and then goes to waste. Untreated grey water cannot be stored for more than 24-36 hours as bacteria begin to grow. Untreated kitchen sink or dishwasher water cannot be used for irrigation purposes as the oils can kill or degrade vegetation.


Drilling for a borehole or well is a gamble that costs between R30,000 and R150,000 without any guarantee of finding water. All borehole, well, spring and river water must be tested by an accredited laboratory as it is likely to need treatment.

Groundwater sources can go dry or become polluted without notice and need to be continuously checked for potable parameters. Remember that groundwater is a limited resource. A reputable professional should design any such system.


While all the above methods can save thousands annually in reduced water bills and the infrastructure can add major value to a property, there may well come a time when water simply runs out and there is none to save. Water treatment and monitoring technologies including real-time telemetry monitoring allow for the potable treatment and reuse of all waste water. This establishes a “closed loop” within a property’s plumbing and water system, making it drought-proof and highly sustainable.

The method involves treating black, grey, rain, borehole, well, spring, river and other freshwater sources with molecular transformation techniques that do not produce any effluent, allowing homeowners to store and reuse the water indefinitely. Costs start at R275,000 (add R300,000 to R500,000 for a new build of a complete system). These are scalable to accommodate one home, a few homes that want to split the cost, an entire city block or entire residential high-rise complexes. Besides not having to pay for water again, residents will be able to bath, shower and irrigate, and enjoy consistently strong water pressure after filling up the system just once.

The system can be installed to supply non-potable residential water-use applications and includes plumbing connections that will allow an unlimited supply of water in an emergency or when the law changes. Thomas Murphy is an American entrepreneur who founded Afrisoul Life Systems in Cape Town. The company implements water harvesting and reuse projects ranging from single-home micro systems to high-rise residential builds.