Water is already an issue in the Western Cape and especially the Scenic South Peninsula, situated as it is at the end of the water pipeline. With the growing population and limited resources for bulk collection of water there will come a time when water restrictions and penalties will be permanently in place. Using water efficiently as well as grey water & rain water harvesting can be used in addition to planting water wise plants? The photo on the RHS is an example of indigenous water wise planting.
Simple and effective ways of water management for all average households:
Water efficiency: Every drop counts – so take responsibility for your own water use.
Water your garden by hand in the cool of the day before 10:00 or after 16:00.
Sweep paving rather than spraying it off with water.
Wash the car using a bucket.
Take short showers and on warm days why not shower in the garden!
Use a dual flush toilet mechanism or place a brick in the cistern.
Rinse washed dishes in a basin and use the rinse water to water herbs or pot plants.
The average suburban garden accounts for about 35% of domestic water consumption, so using your grey water in the garden can significantly reduce your water consumption. Grey water is made up of bath, shower, bathroom sink and washing machine water. It is not advisable to use kitchen water as the fat content is damaging to plant life. An average household (family of 4) typically uses between 200-300l of reusable water per day. The residues, soaps etc in the water, in diluted quantities, can provide useful sulphates and nitrates which if not too concentrated can be beneficial to the garden. It is however advisable to use biodegradable products in the washing machine.
Most of the concerns about grey water are to do with the hygiene aspect and odours of the water. Both these aspects are eliminated if the water is re-used as soon as possible.
Effective grey water management requires the re-use of waste water within 24 hours. This eliminates the growth of bacteria in the water and ensures that the water is still pleasant smelling and hygienic. Systems are available that do this ranging from a small unit that uses the waste water immediately as the bath or shower water flows through the drains.
These through flow systems are ideal for town houses, clusters and small developments. Costs of units start at around R3000.00. Remember that the sooner the water is distributed the better. The photo on the LHS is of a simple home-made flow through solution. Rather get an expert to install a system for you unless you live on a slope where gravity comes to your assistance and you are good at plumbing.
Another option is to collect the waste water in an underground tank. The water is then filtered and re-used within 24 hours with a 0.75Kw pump which distributes the water through an existing or new under or aboveground irrigation system. This system is capable of irrigating a large area, up to 400 m ² and is ideal for a single residential dwelling. Cost of system is about R7000.00 excluding irrigation.
The third option on Grey Water is to have a central tank which water from numerous units is sent to. This means that each unit requires a collection tank and a pump to pump the water to the central tank; it is filtered and treated with either an aerator and a biological additive or is treated with UV to sterilize the water. It is then pumped through a time controlled system into an irrigation system. The only advantage of this system is that the watering times are controlled. Cost implications make this system more viable in larger developments.
Rain water can easily be collected from the gutters of any household and is free water. The cost of an installation for a 5000l tank is about R4500.00 – or if you do it yourself, it costs about R3500. If you wish to use this water for irrigation it is advisable to store at least 15000l to ensure you have enough water for the entire season. Rain water is best used for topping up the swimming pool in summer. Swimming pools loose between 10 and 15% of their water in summer due to evaporation ie: a 50000l pool will need at least 5000l of water to keep it topped up. Although 5000lt rain tanks are large, they can be well screened in the average suburban garden. See photo on the LHS. The old copper drum in the photo on the RHS makes an attractive rain water collector in a courtyard. Save water with a Pool Sediment tank:
Backwash tank for your pool:
Another simple way of saving water and pool chemicals/salt is to have a tank of about 200/300l to backwash the pool into. The water is allowed to settle in the tank and all the sediment will settle at the bottom of the tank over a few days. The water is then drained by gravity feed back into the pool and all the chemicals/salt and water is re-used. An average of about 150l is flushed away during each backwash and rinse cycle.
If all of these measures are put in place the average house hold can save up to 250 l of water per day during the dry season which equates to about 45000 l of water a year. If only 10% of the suburban households would do this it would mean a saving of monumental proportions and would alleviate the pressure on out municipal water supply to a large extent.
For professional advice in the Scenic South Peninsula contact Mike Bekink 0796736240 of Grey Water Systems