TECHNICAL 35
How else can we save water?
By
Patrick Gordon- consultant
In the Plumbing Africa article last month, we discussed how to save water by fitting a water saving device to your taps and mixers, but is there anything else that you can do to save water?
A big area of water consumption in any installation is the toilet. Most persons flush the toilet on an average four times a day. If your toilet has a standard 9l cistern, that means 36l per day per person or 252l per week.
You may have seen that some people place a brick in the cistern to minimise the water capacity of the cistern so that you use less water per flush.
The reason that I mention the presence of solids like paper, is because even though the paper may be cleared from the pan, insufficient water will allow this paper to adhere to slow flowing areas. So, if any excrement or paper is present in the toilet bowl, a full flush will be required to prevent blockages. As mentioned earlier the quantity of water discharged during a full flush can be adjusted using the adjustment on the filling valve.
On some discharge valves the amount of water that remains in the cistern at the end of a full flush can also be adjusted.
However, there are different features built into the cistern mechanisms that will allow you to make adjustments so that you use less water per flush. The cistern filling level can be changed by adjusting the filling valve. Different valves have different means to change the level.
This will also reduce the amount of water discharged during a full flush.
By just following these suggestions you could reduce the average volume of water discharge with each flush to 6l. By using the same means of calculation, the average person will now only use 24l per day or 168l per week. If we calculate this to a single person’ s water consumption to flush the toilet for a year:
Secondly, on many discharge valves the quantity of water allowed to flush for a half-flush can also be set. This means that if the toilet has been used for urine only, without any solids like paper, the amount of water flushed can be reduced.
With 365 days in the year at 36l per day, this equals 13 140l. At only 24l per day equals 8 760l. This means a massive 4 380l of water saved per person. Monetarily this may not be a massive saving, but it will definitely help to lighten the stresses that we place on our ageing infrastructure. PA
½ flush volume adjustment
For any further information on this topic please contact the writer: PA Gordon on patrickg @ splashworks. co. za.
Images by permission from Splashworks and free Google images.
" The cistern filling level can be changed by adjusting the filling valve."
May 2025 Volume 31 I Number 03 www. plumbingafrica. co. za