Borehole vs grey or rainwater recycling?


The recent drought across the country has prompted homeowners to consider alternative water supply systems along with a conscious move to becoming more environmentally friendly energy and water systems. Two such options exist in the form of sinking a borehole and making use of grey or rainwater recycling, but which one is more viable?

Borehole water for home use:

As stated above the severe drought has prompted the need for homeowners to switch water supply systems, the drought being so severe that Mayco member for Water and Watse Services, Xanthea Limberg, says She says it is therefore necessary for residents to shift to alternative water sources. One alternative source of water she suggests is the use of boreholes.

Boreholes have been made use of for a number of years; it is a long, narrow well drilled hole that is used to access underground water.  Water is then pumped to the surface. If properly cared for, a borehole can last up to twenty years. Sinking a borehole however, does come with its risks. There is legislation that restricts the use of boreholes for home water use as they disrupt water tables in the area.  Ben Steenkamp, a director at Durban-based T&T Drilling, which specialises in borehole drilling in KZN, Cape Town, Mozambique and Namibia, said “Obviously with the drought at the moment, there is huge demand for boreholes. But we are also seeing a drop in the water table as a result of the drought. In Harding, we used to dig 40m to 60m for water, but we are now digging 80m to 100m. On the north coast where we once could drill 80m to 120m, we have to now dig 150m.” Therefore legislation has been introduced that outlines that your local municipality may need the borehole to be registered. This depends on the amount of water you use, if it is deemed excessive you may need to get a license.

The water brought from boreholes is not always potable; the system also uses a pump that is run on electricity. In addition, drilling a borehole and registering it can be an extremely expensive and arduous task.  This is because there is no way of knowing for sure how deep the borehole needs to be, if the driller has to drill through solid rock such as dolomite then costs could increase, one needs to make sure there are no sewage pipes or electrical cables nearby, allow two weeks for the installation of the pump system and finally one may have to request water use through their local municipality. This whole process costing upwards of R40 000 and once completed, the borehole is dependent on the water supply and therefore if the water source runs dry then the borehole is rendered useless. Therefore making sinking a borehole a huge risk while other alternative options, which are deemed more viable, exist.


Grey and rainwater recycling:

One such option is grey and rainwater recycling. Grey water recycling within domestic homes is the process of taking used water from baths, showers and basins, filtering it and then storing the filtered water for re-use. Rainwater harvesting systems substantially reduce consumption of potable water by using the roof as a collector of rainwater.

It is estimated that up to 50% of domestic water use does not need to be of a potable quality. For example harvested water can be used for flushing toilets, watering gardens and even used in washing machines.

The advantages of a grey and rainwater recycling system include: lower fresh water use, less strain on septic tank or treatment plant, highly effective purification, greywater is purified to a spectacularly high degree in the upper, most biologically active region of the soil. This protects the quality of natural surface and ground water. As plant growth greywater enables a landscape to flourish. With most grey and rainwater systems there is a variety of options to install; from a simple system that recycles greywater from basins, baths and showers for irrigation to a system that recycles greywater for irrigation, flushing and laundry.

Examples of grey and rainwater systems that can be installed, per Green Your Home, include:

Grey water recycling:

1.1) 50LGR7- This is a simple and cost effective system; it is a separate system and cannot be connected to an owner’s existing irrigation system. This system comes complete with a 30m long high pressure hose and Gardena Pyramid sprinkler. It’s a hands on system; whereby one has to move the hose around daily and cleaned weekly. It can be installed anywhere; in a walkway, driveway, flower bed, wherever – it depends on your set-up.

1.1.1)    Entry level (outlets close to one another with not too much paving between outlets, one hose and sprinkler – approx. R 15 500 (fully installed)

1.1.2)    Various outlets around the house with paving etc. in between. Can have more than one hose with sprinkler – between R 15 500 – R 17 500 approx. (fully installed).

1.2) GW5 :  The recycling of grey water for irrigation, similar to option 1.1 except it can be stored in a tank and connected to an irrigation system. Prices range between R 60 000 – R 80 000 (fully installed), price is dependent on the size of storage tank which in turn is dependent on the volume of grey water that is generated per day.



Rainwater harvesting:

2.1) Slimline 750L

2.1.1) Basic entry level, no extras, downpipe will be fitted directly into the tank @ R 6 500 (fully installed)

2.1.2) Downpipe fitted with a rain filter etc. @ approx. R 9 000 (fully installed).

2.1.3) Two x Slimlines interlinked to increase the storage capacity to 1 500L, installed with a submersible pump, rainfilter etc. @ approx. R 16 500 (fully installed).

2.2) Small-ish (2 200L / 2 500L) tank installed right next to the house with a small submersible pump (I love submersible pumps for aesthetics and security reasons) for approx. R 14 000 (fully installed). It’s simple and straight forward – you connect a hose or sprinkler to the tank and voila. You can also use this for either toilet flushing / clothes washing machine (one application per tank) for approx. R 20 500 (fully installed). You’ll be surprised how much water you’ll save (and money).

2.3) A bigger tank (4 500L/ 5 000L) installed anywhere in the garden, harvesting from one side of the house (two or three downpipes), also installed with a submersible pump (can be bigger) for approx. R 25 000 (fully installed)




Both grey and rainwater recycling and boreholes are options available to a consumer who is looking to save money on his/her water bills, save water and aid the environment in doing so. However one option is more viable than the other. Sinking a borehole as explained above can be a long and expensive task to undertake without a guarantee on its lifespan, as it relies on the water source below. Alternatively a grey or rainwater recycling system can be tailored to your budget and what you want. The risks associated with grey and rainwater recycling is less than that of sinking a borehole, as well as being much easier to install and both systems doing similar things. Therefore it’s fair to conclude that grey and rainwater recycling would be the best option if one is looking for an alternative water system.

Contact us for a quote on a Grey or Rain Water Recycling system for your home

Author – Ashton Ibbitson, 13/02/2015 copyright Green Building Africa


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