Precision Meters: Effective use of Water (Part A)
System Users – Residential , Industry and Agriculture:
All these groups share two areas namely Plumbing / Fixtures and Behavioural that need to be examined together so as to determine the best of practice option for each site in an endeavour to be as water efficient as possible and as a consequence result in more effective use and conservation of precious water resources.
a) Plumbing / Fixtures:
the minimum is to have Plumbing / Fixtures initially installed that are designed to save water from day one.
the minimum is to have older, less efficient water fittings replaced wherever possible.
By following the above, is is estimated that an average three member household could reduce its water consumption by about 20,000 litres per annum.
b) Water Saving Plumbing / Fixtures:
Low Flush Toilet:
Conventional flush toilets use between 13 and 18 litres of water per flush. By comparison low flush toilets use only 6 litres of water or less and since they use that much less water, they also, as a consequence, reduce the volume of waste water produced too.
It is even practical to change conventional toilets to low flush units as the savings, expressed in value terms would be recovered in approximately 5 years.
An alternate to replacing conventional, high usage toilets is to limit to some extent the amount of water that they use with each flush by placing one or more objects such as a conventional brick or plastic bottle filled with water or pebbles, making sure that these do not impede the flushing mechanism or water flow, in the toilet tank. Water used for each flush will then be reduced by the volume of the object/s placed in the toilet tank.
A second alternate is to install, where possible, a composting toilet that uses NO water at all. As these units use no water, they require NO plumbing, are simple to maintain and are available as non electric or with solar powered 12v vent fan if this is a requirement.
Low Flow Showerhead/s:
Showers account for about 20 percent of total indoor water use. By replacing standard 17 litres per minute shower heads with 9 litres per minute heads, a family of four can save approximately 75,000 litres of water per year.
This saving extends too, to the amount of energy that would have been used to heat the 75,000 litres of water now NOT being used so represents a substantial reduction all round.
A requirement when using the kitchen sink is to remove excess food particles on plates and utensils before washing these or to cleanse fruit, vegetables or food prior to processing or cooking.
Effective wetting to achieve the above is therefore necessary and so tap aerators that break flowing water into fine droplets entraining air while maintaining wetting effectiveness, are inexpensive devices that can be installed on sink taps to achieve efficient wetting. These aerators are easily installed and reduce water usage by as much as 60 percent while still maintaining a strong flow.
Couple these aerators with more efficient kitchen and bathroom taps that use only 7.5 litres of water per minute, unlike standard taps, which use 11 to 18 litres per minute for less water usage.
As flow rate is directly related to pressure, the maximum water flow from any fixture operating on a fixed setting can be reduced if the water pressure is reduced. For example, a reduction in pressure from 7.0bar to 3.5bar can result in a water flow reduction of about one third at an outlet.
Water pressure reduction is able to save water in other ways too as it could reduce the likelihood of:
• Leaking water pipes.
• Dripping taps. • Breakdowns in the plumbing system.
Water meters are generally ignored by the industry, residential and agriculture System Users, believing that they are solely for the use of the authority that ‘reads’ them and then charges for the water used at the applicable tariff.
It is, however, recommended that the System User also ‘reads’ their own meter on a given cycle that could be weekly, fortnightly or monthly and preferably when knowing that there is no water being used during the reading and records these readings.
The reasons for this recommendation are:
• The user will rapidly become sensitised to the water used.
• A potential leak will be revealed if the water meter dial or numerical display is moving when it is known that no water is being used at that moment.
• The amount of water used can be compared with the amount that is being charged to determine whether there are any discrepancies.
• Recorded consumption could indicate period/s of increased water consumption.
• These periods would then be apportioned to some or other activity which activity.
• These could then be examined to determine whether a behavioural change would result in less water being used for that activity and so reduce water usage.
Water conservation in landscaping uses plants that need little water and grouping these saving not only water but labor and fertilizer as well.
Scheduling irrigation for early morning or evening reduces water wasted due to evaporation during warm daylight hours.
Another practice that could be applied to residential landscape irrigation is the use of cycle irrigation methods that provides the right amount of water at the right time and place, for optimal growth and to improve penetration and reduce runoff.
Couple the above with the use of low precipitation rate sprinklers that have better distribution uniformity, bubbler / soaker systems, or drip irrigation systems.
Xeriscape landscaping is an innovative, comprehensive approach to landscaping for water conservation and pollution prevention.
Traditional landscapes might incorporate one or two principles of water conservation, but xeriscape landscaping uses all of the following:
• Planning and design.
• Soil analysis.
• Selection of suitable plants.
• Practical turf areas.
• Efficient irrigation.
• Use of mulches.
• Regular and appropriate maintenance.
Benefits of xeriscape landscaping include:
• Reduced water use.
• Decreased energy use due to less pumping and treatment needed.
• Reduced heating and cooling costs because of carefully placed trees.
• Decreased storm water and irrigation runoff.
• Fewer wastes. • Increased habitat for plants, birds and animals.
• Lower labor and maintenance costs.